west

A Pretty Good House in Southern California

Big Bear Lake, CA

May 2 2016 By Stu Turner | 7 comments

General Specs

Location: Big Bear Lake, CA
Bedrooms: 3
Bathrooms: 2.5
Living Space : 2258 sqf
Cost (USD/sq. ft.): $107/sqf

Cost per square foot excludes the PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow. system and all soft costs, and includes the 286-square-foot garage.

Construction

Foundation: Perimeter frost walls and slab on grade.

Foundation insulation: Horizontal layer of 6-in. EPSExpanded polystyrene. Type of rigid foam insulation that, unlike extruded polystyrene (XPS), does not contain ozone-depleting HCFCs. EPS frequently has a high recycled content. Its vapor permeability is higher and its R-value lower than XPS insulation. EPS insulation is classified by type: Type I is lowest in density and strength and Type X is highest. under slab (R-25), with 2 in. of vertical EPS (R-8) at slab perimeter.

Above-grade walls: Double-stud walls (total thickness, 9 in.) with OSB sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. .

Above-grade wall insulation: 3.5 inches of open-cell spray foam and 5.5 inches of mineral wool (totaling R-34)

Siding: Fiber-cement and stone veneer.

Roof construction: Raised-heel scissors trusses, OSB sheathing, asphalt shingles.

Roof insulation: 18 in. (R-60) of blown-in cellulose.

Windows: Pella 350 windows with triple glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill.; U-factors range from 0.18 to 0.26.

Domestic hot water: Navien 199,000 BTUBritish thermal unit, the amount of heat required to raise one pound of water (about a pint) one degree Fahrenheit in temperature—about the heat content of one wooden kitchen match. One Btu is equivalent to 0.293 watt-hours or 1,055 joules. gas-fired condensing tankless water heater (Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners., 0.97 EF(EF). Efficiency measure for rating the energy performance of dishwashers, clothes washers, water heaters, and certain other appliances. The higher the energy factor, the greater the efficiency. In some appliances EF reflects the percentage of energy going into the appliance that is turned into useful energy.).

Mechanical ventilation: Exhaust-only system complying with ASHRAE 62.2A standard for residential mechanical ventilation systems established by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Among other requirements, the standard requires a home to have a mechanical ventilation system capable of ventilating at a rate of 1 cfm for every 100 square feet of occupiable space plus 7.5 cfm per occupant..

Space heating: Two 12,000 BTU/h Mitsubishi Mr. Slim Hyperheat ductless minisplits.

Fire safety: Residential fire sprinkler system, all windows have tempered glass, non-ember admitting attic vents, fire-resistant exterior materials.

Energy

Blower door test results: 1.8 ach50

HERS Index: 53 (without PV), based on California’s 2008 Title 24 Energy Code (in effect until July 2014).

Photovoltaic system rated at 5 kW.

100% LEDLight-emitting diode. Illumination technology that produces light by running electrical current through a semiconductor diode. LED lamps are much longer lasting and much more energy efficient than incandescent lamps; unlike fluorescent lamps, LED lamps do not contain mercury and can be readily dimmed. lighting (except for 2 accent fixtures)

Water Efficiency

Low-flow water fixtures, 1.28 GPFGallons per flush. Measurement of water use in toilets. Since 1992, toilets sold in the United States have been restricted to 1.6 gpf or less. The standard for high-efficiency toilets (HETs) is 1.28 gpf. toilets, no outside irrigation system (100% native landscaping + gravel).

Indoor Air Quality

All paints and adhesives are low-VOC.

All furniture and cabinets are formaldehyde-free.

No carpeting; the upstairs flooring is wood laminate and downstairs flooring is tile.

A high-performance design for the mountains above Los Angeles

A few years into the housing bust, I started shopping around for a cabin to use as a getaway and vacation rental. I live in San Diego and I set my sights on the resort town of Big Bear Lake, in the San Bernardino mountains northeast of Los Angeles. Just 2½ hours away, it was a place where my family and I had spent many weekends skiing, snowboarding, mountain biking, and fishing.

Lessons Learned

Exhaust fans. Although I think the constant pressure exhaust-only fan from Conservation Technologies is a very elegant system, if I did it over again, I would go with something simpler like Panasonic WhisperQuiet exhaust fans in each bathroom. The Conservation Technologies fan required a lot of ducting and is not as quiet as I had hoped. Although it is rated at only 55 decibels, I had to really work on isolating the fan from the mounting and the ducting to get the noise to where it was barely noticeable through an insulated wall. But I think a bigger issue with the fan is that it is such a specialized product, what happens when it needs to be serviced or replaced? If I had used standard bath fans, that would not be an issue. I doubt any HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. companies in Big Bear would touch my “crazy” inline Swedish fan system.

Mysterious air leaks. My air leakage rate (1.8 ach50) came in a lot higher than I had hoped for. At some point I would love to do some follow-up testing to try to figure out where the leakage points are. I don’t think that the air leakage has impacted my performance very much, since I am using an exhaust-only ventilationMechanical ventilation system in which one or more fans are used to exhaust air from a house and make-up air is supplied passively. Exhaust-only ventilation creates slight depressurization of the home; its impact on vented gas appliances should be considered. system that (hopefully) results in a negatively pressured interior with very little infiltration. I suspect that there are leaks at my sliding windows and my sliding glass door, as these are generally more leaky than awning windows. Another factor is the number of exterior doors; I have four but I probably could have made the house work with two.

I should have specified Zip sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. . Another thing I would have changed is my air barrierBuilding assembly components that work as a system to restrict air flow through the building envelope. Air barriers may or may not act as a vapor barrier. The air barrier can be on the exterior, the interior of the assembly, or both. and insulation choices. Seeing all the trimmed-off foam being packed up in trash bags and hauled away seemed like a sickening waste. I would have been better off using Zip sheathing as my air barrier, and some kind of cellulose (I have since found a contractor who installs damp-spray cellulose) or 100% rock wool as my wall insulation.

I should have included energy monitoring equipment. I wish I had invested in a simple energy monitoring system. I am looking to install one before next winter, so I can at least track the energy use of my minisplits.

Minisplits are fairly quiet, but have some noticeable sound. The minisplit indoor units are extremely quiet and unassuming. The outside fan coils are also very quiet, if you are standing right next to them. But because my exterior units were hung on the exterior wall, I do notice some sound vibrations through the wall when the exterior units are really working. So I can see the wisdom of mounting the exterior units on a concrete pad not attached to the house.

Stu Turner, M.S. Architecture, is an occasional environmental science T.A. at the NewSchool of Architecture + Design. He is also a member of the residential committee of the San Diego chapter of the USGBCUnited States Green Building Council (USGBC). Organization devoted to promoting and certifying green buildings. USGBC created the LEED rating systems..


Stu Turner

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Denver Developer Focuses on Zero-Energy Homes

Denver, CO

May 28 2015 By | 1 comments

General Specs and Team

Location: Denver, CO
Bedrooms: 3
Bathrooms: 2.5
Living Space : 2115 sqf

Builder: Bill Rectanus, New Town Builders

Energy consultants:Peter Oberhammer, EnergyLogic, Inc.

Construction

Foundation: Conditioned basement with R-19 interior wall insulation

Wall construction: Double-stud 2x4 walls, advanced-framed, with 9.5 inches blown fiberglass (R-40.7)

Windows: Double-pane, low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor., vinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate).-framed, U=0.25, SHGCSolar heat gain coefficient. The fraction of solar gain admitted through a window, expressed as a number between 0 and 1.=0.27

Roof: Vented attic framed with 14-inch raised-heel trusses

Attic insulation: R-50 blown-in fiberglass attic insulation

Energy

Air leakage rate: 2.11 ach50

HERSIndex or scoring system for energy efficiency established by the Residential Energy Services Network (RESNET) that compares a given home to a Home Energy Rating System (HERS) Reference Home based on the 2006 International Energy Conservation Code. A home matching the reference home has a HERS Index of 100. The lower a home’s HERS Index, the more energy efficient it is. A typical existing home has a HERS Index of 130; a net zero energy home has a HERS Index of 0. Older versions of the HERS index were based on a scale that was largely just the opposite in structure--a HERS rating of 100 represented a net zero energy home, while the reference home had a score of 80. There are issues that complicate converting old to new or new to old scores, but the basic formula is: New HERS index = (100 - Old HERS score) * 5. Index: 38 without PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow.; -3 with an 8-kW PV system

Estimated annual energy use: $1,414 without PV, $5 with PV

Actual annual energy use: Unknown

PV arrays are an available option

Space heat and cooling: Air-source heat pumpHeat pump that relies on outside air as the heat source and heat sink; not as effective in cold climates as ground-source heat pumps., 12.7 HSPF, 19.8 SEER(SEER) The efficiency of central air conditioners is rated by the Seasonal Energy Efficiency Ratio. The higher the SEER rating of a unit, the more energy efficient it is. The SEER rating is Btu of cooling output during a typical hot season divided by the total electric energy in watt-hours to run the unit. For residential air conditioners, the federal minimum is 13 SEER. For an Energy Star unit, 14 SEER. Manufacturers sell 18-20 SEER units, but they are expensive. , with forced-air ductwork for distribution; 97.3 AFUEAnnual Fuel Utilization Efficiency. Widely-used measure of the fuel efficiency of a heating system that accounts for start-up, cool-down, and other operating losses that occur during real-life operation. AFUE is always lower than combustion efficiency. Furnaces sold in the United States must have a minimum AFUE of 78%. High ratings indicate more efficient equipment. gas furnace for backup.

Ventilation: Exhaust-only 15-watt fan rated at 71 cfm

Domestic hot water: 0.947 EF(EF). Efficiency measure for rating the energy performance of dishwashers, clothes washers, water heaters, and certain other appliances. The higher the energy factor, the greater the efficiency. In some appliances EF reflects the percentage of energy going into the appliance that is turned into useful energy. tankless gas water heater

Lighting: 100% CFLCompact fluorescent lamp. Fluorescent lightbulb in which the tube is folded or twisted into a spiral to concentrate the light output. CFLs are typically three to four times as efficient as incandescent lightbulbs, and last eight to ten times as long. CFLs combine the efficiency of fluorescent light with the convenience of an Edison or screw-in base, and new types have been developed that better mimic the light quality of incandescents. Not all CFLs can be dimmed, and frequent on-off cycling can shorten their life. Concerns have been raised over the mercury content of CFLs, and though they have been deemed safe, proper recycling and disposal is encouraged.

Appliances: All Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners.

Water Efficiency

WaterSenseProgram developed and administered by the U.S. Environmental Protection Agency to promote and label water-efficient plumbing fixtures. compliant fixtures

"Smart" recirculation pump that learns occupants' behavior

Green Materials and Resource Efficiency

Beetle-kill lumber used for all framing lumber

Roadways, bridges, and bike paths use recycled concrete

Certification

DOE Zero Energy Ready

DOE Energy Star

EPA Indoor airPLUS

Double-stud walls effectively reduce thermal bridging

A Denver-area developer, New Town Builders, is aiming to make all of its new homes zero-energy-ready by the end of 2015.

“Our goal is to be 100% U.S. Department of Energy (DOEUnited States Department of Energy.) Zero Energy Ready certified on all of our single-family homes,” said Bill Rectanus, vice president of New Town Builders, which plans to build 150 single-family homes in the Denver metro area in 2015.


Courtesy U.S. Department of Energy

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Modern Dream Home is Energy-Positive

Climate Zone 4C, Seattle, WA

May 21 2015 By | 11 comments

General Specs and Team

Location: Climate Zone 4C, Seattle, WA
Bedrooms: 4
Bathrooms: 3.5
Living Space : 3192 sqf
Cost (USD/sq. ft.): $200/sqf

Builder: Ted Clifton, Jr., TC Legend Homes

Construction

Foundation: Slab on grade with R-28 ICFs at slab edge and R-20 horizontal rigid foam under slab

Walls: 6-inch SIPs rated at R-26

Windows: VinylCommon term for polyvinyl chloride (PVC). In chemistry, vinyl refers to a carbon-and-hydrogen group (H2C=CH–) that attaches to another functional group, such as chlorine (vinyl chloride) or acetate (vinyl acetate). windows with low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. triple glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill.. U-factorMeasure of the heat conducted through a given product or material—the number of British thermal units (Btus) of heat that move through a square foot of the material in one hour for every 1 degree Fahrenheit difference in temperature across the material (Btu/ft2°F hr). U-factor is the inverse of R-value. is 0.14; SHGCSolar heat gain coefficient. The fraction of solar gain admitted through a window, expressed as a number between 0 and 1. is 0.55

Roof: 12-inch SIPs rated at R-46; standing-seam metal roofing

Siding: Prefinished fiber-cement siding over wrinkled housewrap

Energy

HERSIndex or scoring system for energy efficiency established by the Residential Energy Services Network (RESNET) that compares a given home to a Home Energy Rating System (HERS) Reference Home based on the 2006 International Energy Conservation Code. A home matching the reference home has a HERS Index of 100. The lower a home’s HERS Index, the more energy efficient it is. A typical existing home has a HERS Index of 130; a net zero energy home has a HERS Index of 0. Older versions of the HERS index were based on a scale that was largely just the opposite in structure--a HERS rating of 100 represented a net zero energy home, while the reference home had a score of 80. There are issues that complicate converting old to new or new to old scores, but the basic formula is: New HERS index = (100 - Old HERS score) * 5. Index: 42 without PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow., -1 with PV

Projected annual utility costs: $797 without PV, $21 with PV

Annual energy savings compared to code-minimum house: 15,367 kWh without PV, 25,067 kWh with PV

Renewable energy: 9.7-kW PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow. system

Heating, cooling and domestic hot water: 5-ton air-to-water heat pumpHeating and cooling system in which specialized refrigerant fluid in a sealed system is alternately evaporated and condensed, changing its state from liquid to vapor by altering its pressure; this phase change allows heat to be transferred into or out of the house. See air-source heat pump and ground-source heat pump. with a COPEnergy-efficiency measurement of heating, cooling, and refrigeration appliances. COP is the ratio of useful energy output (heating or cooling) to the amount of energy put in, e.g., a heat pump with a COP of 10 puts out 10 times more energy than it uses. A higher COP indicates a more efficient device . COP is equal to the energy efficiency ratio (EER) divided by 3.415. 4.5 provides hot water for radiant floors and preheats domestic hot water; a 50-gallon electric tank stores water and boosts temperature.

Lighting: 100% LEDLight-emitting diode. Illumination technology that produces light by running electrical current through a semiconductor diode. LED lamps are much longer lasting and much more energy efficient than incandescent lamps; unlike fluorescent lamps, LED lamps do not contain mercury and can be readily dimmed.

Appliances: Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. refrigerator, dishwasher, clothes washer

Water Efficiency

Low-flow plumbing fixtures

Indoor Air Quality

Air infiltration rate: 0.97 ach50

Mechanical ventilation: 5.4-watt exhaust fan in laundry runs continuously at 30 cfm to meet ASHRAE 62.2A standard for residential mechanical ventilation systems established by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers. Among other requirements, the standard requires a home to have a mechanical ventilation system capable of ventilating at a rate of 1 cfm for every 100 square feet of occupiable space plus 7.5 cfm per occupant. requirements. A 200-cfm supply air fan comes on automatically when the 400-cfm range hood fan is turned on.

Certification

DOE Zero Energy Ready

Northwest Energy Star Certified

EPA Indoor airPLUS

The PV system provides enough electricity for the home and an electric car

A Seattle couple spent two years searching for their dream home before deciding to build a new custom home. They turned to zero-energy-home builder Ted Clifton, Jr., who built them a modern two-story house with a mother-in-law suite and views of Lake Washington from the rooftop deck.

Clifton, the owner of of TC Legend Homes, calls the home a “positive energy home” — one that produces more energy than the home itself consumes. In fact, the home should produce enough electricity to power an electric car with the charging station set up in the garage.

Lessons Learned

Customers need to be convinced that what they see in magazines isn't always great design, says builder Ted Clifton, Jr. In the case of this house, the plans called for shading some of the windows, but the homeowners had a different idea.

“People look at Dwell magazine and see what they want — simple, clean designs — but that doesn’t always work. The original plans drawn by the architect had shading over the windows on the south side. But the homeowners didn't like the look of them so they weren't included. We used high-solar-gain windows, which are good for the winter, but without shading, they allow heat to pass through in the summer. I would prefer to maintain control over those design decisions if I could,” said Clifton.

The project ended up being inspected more often than a conventional home because the city was unfamiliar with some of the processes.

“The city required special inspections every step of the way because we used SIPs. The jurisdiction wasn't as familiar with those construction techniques.”

Clifton has discovered that inspectors, engineers, architects, and yes, builders too, don’t always keep up with the latest innovations from manufacturers. “There is sometimes a disconnect of industrial standards and engineered standards. For example, we learned that we could use thinner nails for much of this project, built with SIPs. Those nails were half the cost of what the plans called for,” he said.

“All of us are responsible to collaborate and on keep up-to-date. We need to provide each other feedback,” he said.

Overall, the building industry hasn’t changed much, he said. “The best place to point a finger is at yourself. Then do it. That’s my mentality. If we want to change it, we all have to step up and pay attention. I learn something new from my entry-level laborer every day. One needs to be open to new ideas and figure out what works best,” said Clifton.


Courtesy of the U.S. Department of Energy

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New California Home Meets the Passivhaus Standard

Climate Zone 4, San Jose, CA

Apr 27 2015 By | 0 comments

General Specs and Team

Location: Climate Zone 4, San Jose, CA
Bedrooms: 5
Bathrooms: 3.5
Living Space : 3198 sqf
Cost (USD/sq. ft.): $350/sqf

Design-BuildCompany that handles house design and construction. Since both services are provided by the same firm, integrated design can often be more easily achieved. Team: Allen Gilliland and Bronwyn Barry, One Sky Homes

Construction

Foundation: ICFInsulated concrete form. Hollow insulated forms, usually made from expanded polystyrene (EPS), used for building walls (foundation and above-ground); after stacking and stabilizing the forms, the aligned cores are filled with concrete, which provides the wall structure. crawl space walls, total of 4 in. of EPSExpanded polystyrene. Type of rigid foam insulation that, unlike extruded polystyrene (XPS), does not contain ozone-depleting HCFCs. EPS frequently has a high recycled content. Its vapor permeability is higher and its R-value lower than XPS insulation. EPS insulation is classified by type: Type I is lowest in density and strength and Type X is highest. plus 8 in. concrete (R-22 for perimeter wall).

Crawl space floor: 4 in. of crushed stone, polyethylene vapor barrier, 3 in. horizontal EPS (R-14), concrete slab.

Above-grade walls: 2x6 24 in. o.c., advanced framed, R-23 dense-packed cellulose cavity insulation plus 1-in. EPS over plywood sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. ; ¼-in. plastic mesh to create ventilated rain screen; housewrap, wire lath; traditional 3-coat stucco claddingMaterials used on the roof and walls to enclose a house, providing protection against weather. .

Windows: Serious & Sorpethaler wood-framed windows with low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor. argonInert (chemically stable) gas, which, because of its low thermal conductivity, is often used as gas fill between the panes of energy-efficient windows. -filled triple glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill.; SHGCSolar heat gain coefficient. The fraction of solar gain admitted through a window, expressed as a number between 0 and 1.=0.49 on south and SHGC=0.29 on north, east, and west windows; U=0.2.

Roof/ceiling construction: R-51 blown cellulose on attic floor; raised-heel trusses; foil-faced radiant barrier sheathing; asphalt shingles; continuous eave and ridge vents.

HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building.: Split-system air-source heat pumpHeat pump that relies on outside air as the heat source and heat sink; not as effective in cold climates as ground-source heat pumps.; SEER(SEER) The efficiency of central air conditioners is rated by the Seasonal Energy Efficiency Ratio. The higher the SEER rating of a unit, the more energy efficient it is. The SEER rating is Btu of cooling output during a typical hot season divided by the total electric energy in watt-hours to run the unit. For residential air conditioners, the federal minimum is 13 SEER. For an Energy Star unit, 14 SEER. Manufacturers sell 18-20 SEER units, but they are expensive. 21, HSPF 10.

Energy

Blower-door testTest used to determine a home’s airtightness: a powerful fan is mounted in an exterior door opening and used to pressurize or depressurize the house. By measuring the force needed to maintain a certain pressure difference, a measure of the home’s airtightness can be determined. Operating the blower door also exaggerates air leakage and permits a weatherization contractor to find and seal those leakage areas. results: 0.57 ach50

Estimated energy use: 10,000 kWh/year, of which 2,000 kWh is for heating and cooling

Estimated annual utility costs: Without PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow., $1,972; with PV $0.

Estimated annual energy cost savings: (When compared to a home built to the 2008 California Title 24 Energy Code) Without PV $1,095; with PV: $2,900.

Actual annual energy use (2013): Not counting the electric vehicle, the house used 9,325 kWh. PV production exceeded use by 1,492 kWh. Including electric vehicle charging, the PV array produced 84% of the total site electricity consumption.

PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow. system: 6.4 kW of PV (28 panels, each 230 watts)

Solar thermal system: 3 solar thermal collectors are connected to a solar storage tank; backup provided by a gas-fired, 96% efficient condensing tank-type water heater.

Appliances: Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. clothes washer, dishwasher, refrigerator/freezer

Lighting: 40% CFLCompact fluorescent lamp. Fluorescent lightbulb in which the tube is folded or twisted into a spiral to concentrate the light output. CFLs are typically three to four times as efficient as incandescent lightbulbs, and last eight to ten times as long. CFLs combine the efficiency of fluorescent light with the convenience of an Edison or screw-in base, and new types have been developed that better mimic the light quality of incandescents. Not all CFLs can be dimmed, and frequent on-off cycling can shorten their life. Concerns have been raised over the mercury content of CFLs, and though they have been deemed safe, proper recycling and disposal is encouraged. , 40% LEDLight-emitting diode. Illumination technology that produces light by running electrical current through a semiconductor diode. LED lamps are much longer lasting and much more energy efficient than incandescent lamps; unlike fluorescent lamps, LED lamps do not contain mercury and can be readily dimmed. and 20% halogen; vacancy sensors in all rooms. Closets, bath heaters, and utility lighting on count-down timers. All exterior lighting is Energy Star rated and on timers with photocell shut-offs.

Other: Energy management system. Electric vehicle charging station with prewiring for a second charger

Water Efficiency

• Low-flow plumbing fixtures

GraywaterWastewater from a building that does not include flush-water from toilets and (as most commonly defined) water from kitchen sinks or dishwashers. In some places, graywater can be collected and used for subsurface irrigation. irrigation system

• On-demand hot waterSystem to quickly deliver hot water to a bathroom or kitchen when needed, without wasting the water that has been sitting in the hot-water pipes, which circulates back to the water heater. recirculation with occupancy sensors

Indoor Air Quality

HRV(HRV). Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor. HRVs recover 50% to 80% of the heat in exhausted air. In hot climates, the function is reversed so that the cooler inside air reduces the temperature of the incoming hot air. with MERV 13 filters, 84% sensible heat recovery efficiency.

Night Ventilation (economizer) with MERV 13 filters.

Meets or exceeds EPA indoor airPLUS verification checklist.

Certification

  1. PassivhausA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates.
  2. LEEDLeadership in Energy and Environmental Design. LEED for Homes is the residential green building program from the United States Green Building Council (USGBC). While this program is primarily designed for and applicable to new home projects, major gut rehabs can qualify. Platinum
  3. DOEUnited States Department of Energy. WaterSenseProgram developed and administered by the U.S. Environmental Protection Agency to promote and label water-efficient plumbing fixtures.
  4. EPA Indoor Air Plus
  5. DOE Zero Energy Ready

ICFs and advanced framing techniques used throughout

This energy-efficient house in San Jose, California, not only produces enough solar electricity to meet its annual energy needs, it also complies with the stringent PassivhausA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. standard.

The design-buildCompany that handles house design and construction. Since both services are provided by the same firm, integrated design can often be more easily achieved. team of Allen Gilliland and Bronwyn Barry of One Sky Homes were behind the spec home and succeeded in meeting the Passivhaus standard and the performance requirements of the U.S. Department of Energy’s Zero Energy Ready Home program.

Lessons Learned

Gilliland is looking forward to the day when smart heat pumps will integrate all of the HVAC(Heating, ventilation, and air conditioning). Collectively, the mechanical systems that heat, ventilate, and cool a building. functions — heating, cooling, HRV(HRV). Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor. HRVs recover 50% to 80% of the heat in exhausted air. In hot climates, the function is reversed so that the cooler inside air reduces the temperature of the incoming hot air. balanced ventilationMechanical ventilation system in which separate, balanced fans exhaust stale indoor air and bring in fresh outdoor air in equal amounts; often includes heat recovery or heat and moisture recovery (see heat-recovery ventilator and energy-recovery ventilator). , and night cooling — into one system with one controller for the homeowner. He noted that the 2013 California Energy Code, which went into effect July 1, 2014, makes mechanical night ventilation prescriptive in some climate zones in California and gives credit for it in other locations in the state.

Bronwyn Barry shed some more light on the cooling system: “It turns out that we didn’t need such a large mechanical cooling system which we installed in this project. We’ve found that we can eliminate additional cooling systems because in our climate we can use a minisplit in conjunction with the HRV in bypass mode to supply all the cooling we need.”

Barry said that the design of the project evolved once they decided to go for the Passivhaus standard. “The house wasn’t originally designed for the Passive HouseA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. standard but we discovered and used the Passive House Planning Package (PHPP) after the design was set. That allowed us to dial in everything on this house to meet our NZE performance targets." And this change now informs their latest projects. "We’ve moved away from designs that include too many bump-outs. Our newer projects are much simpler shapes as they are more cost-effective for high efficiency.”

The firm's approach to air sealing also evolved, said Barry: “One thing we now do differently: Instead of using the drywall ceiling as an air barrierBuilding assembly components that work as a system to restrict air flow through the building envelope. Air barriers may or may not act as a vapor barrier. The air barrier can be on the exterior, the interior of the assembly, or both., which proved difficult because of all our lighting penetrations, we now establish the air barrier on the exterior roof sheathingMaterial, usually plywood or oriented strand board (OSB), but sometimes wooden boards, installed on the exterior of wall studs, rafters, or roof trusses; siding or roofing installed on the sheathing—sometimes over strapping to create a rainscreen. . We typically apply an elastomeric liquid sealant to the plywood layer around our whole building envelopeExterior components of a house that provide protection from colder (and warmer) outdoor temperatures and precipitation; includes the house foundation, framed exterior walls, roof or ceiling, and insulation, and air sealing materials.. This is then covered with rigid exterior insulation, a WRB and a rainscreenConstruction detail appropriate for all but the driest climates to prevent moisture entry and to extend the life of siding and sheathing materials; most commonly produced by installing thin strapping to hold the siding away from the sheathing by a quarter-inch to three-quarters of an inch. finish layer.”

Gilliland said One Sky has enjoyed the experience of learning from this project and is committed to zero energy construction. His only concern is motivating buyers to seek it out. “Once people experience it, they want it. Our customers will tell you, you just can’t believe it. It’s so much better living in these homes. People just haven’t heard enough about it yet.”

That may change soon, in California anyway. The California Public Utilities Commission and the California Energy Commission have adopted as a goal that all new residential construction will be zero net energy by 2020.


Courtesy of the U.S. Department of Energy

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  1. One Sky Homes

A Passive Solar Home from the 1980s

Boulder, CO

Feb 25 2014 By Robert Opaluch | 20 comments

General Specs

Location: Boulder, CO
Bedrooms: 3
Bathrooms: 1.5
Living Space : 1480 sqf

Construction

Foundation: Perimeter concrete grade beams surrounding a slab on grade

Vertical insulation at perimeter of foundation: R-45 XPSExtruded polystyrene. Highly insulating, water-resistant rigid foam insulation that is widely used above and below grade, such as on exterior walls and underneath concrete floor slabs. In North America, XPS is made with ozone-depleting HCFC-142b. XPS has higher density and R-value and lower vapor permeability than EPS rigid insulation.

Wall construction: 2x6 studs, 24" o.c.

Wall insulation: R-19 fiberglass batts plus either ½-inch or 1-inch polyisocyanurate on the exterior

Siding: Diagonal 3/4-inch shiplap cedar boards

Ceiling insulation: R-60 fiberglass batts

Windows: Double-glazed sliders, casements, and awnings

Roof framing: Roof trusses (unconditioned attic)

Roofing: Cedar shingles

Domestic hot water: Two batch-type solar thermal collectors with electric resistance backup

Space heating: Passive solar design with electric resistance backup

Energy

5600 heating degree day climate

Renewable energy equipment: Two passive (batch-type) solar thermal collectors

Water Efficiency

Plumbing core was designed to keep pipe runs short

The design of this two-story home in Boulder, Colorado, adhered to timeless passive solar principles

Back in the early 1980s, I built a 1,480-square-foot passive solar home in Boulder, Colorado. There have been substantial improvements in active solar equipment since then. But today’s passive solar design principles are quite similar to the principles preached in the early 1980s. Solar energy provides almost all the winter heating and hot water for this home. The cost savings I achieved by eliminating a central heating system were invested in thermal massHeavy, high-heat-capacity material that can absorb and store a significant amount of heat; used in passive solar heating to keep the house warm at night. , additional insulation, and better glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill., so no additional construction costs were incurred compared to conventional construction.

Lessons Learned

What would I do differently next time? In my most recent design for a superinsulated home designed for a cloudy, cold climate, some specifications were different:

• Use even higher insulation levels (R-80+ ceiling, R-40+ walls and floor, R-5 windows)
• Eliminate leaky sliding glass doors and only use triple-pane, low-eLow-emissivity coating. Very thin metallic coating on glass or plastic window glazing that permits most of the sun’s short-wave (light) radiation to enter, while blocking up to 90% of the long-wave (heat) radiation. Low-e coatings boost a window’s R-value and reduce its U-factor., argonInert (chemically stable) gas, which, because of its low thermal conductivity, is often used as gas fill between the panes of energy-efficient windows. -filled casement and fixed windows
• Reduce the west-facing glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill. to almost none, which is easy with a long east-west axis footprint
• Use updated air and moisture sealing products and techniques
• Install an HRV(HRV). Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor. HRVs recover 50% to 80% of the heat in exhausted air. In hot climates, the function is reversed so that the cooler inside air reduces the temperature of the incoming hot air.
• Don’t use as much thermal massHeavy, high-heat-capacity material that can absorb and store a significant amount of heat; used in passive solar heating to keep the house warm at night. for a cloudy climate, especially the concrete block active hot air storage system

Recommendations based on this experience:

• Choose a lot based on location, location, and location — and also solar access and maybe south-facing views
• Orient the home and most of the windows to face south, with a longer east-west axis
• Make the time and investment for massive insulation, tight building materials and practices, and the best quality materials
• Use kitchen layout standards for sufficient space on the sides of the refrigerator, cooktop, sink, and ovens
• Install lots of electrical outlets and convenience features
• Learn to do what you don’t know from experts, books, the Internet, and educational events
• Take the risk and build your own house

Bob Opaluch has had a lifelong interest in energy-efficient homebuilding, passive solar design, and designing and building furniture. He designed and built the passive solar home in Boulder, renovated a house in Massachusetts, and designed and built dozens of furniture pieces for friends and family. He recently led a course in Sustainable Architecture for Lifelong Learning Collaborative, an adult ed organization in Providence, R.I. Bob has degrees in philosophy and applied mathematics from Brown University, and MA and PhD degrees in psychology from UCLA. He was a psychology professor for five years, and a usability and design engineer for 20 years. Bob is a divorced single parent. His son started college this year.


Robert Opaluch

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  1. Robert Opaluch

A Net-Zero-Energy House for $125 a Square Foot

Seattle, WA

Jan 7 2013 By Eric Thomas | 22 comments

General Specs and Team

Location: Seattle, WA
Bedrooms: 3
Bathrooms: 2
Living Space : 1915 sqf
Cost (USD/sq. ft.): $124/sqf

(Note: Reported cost of $124/square foot excludes the cost of the land and the value of the PV incentives. The cost per square foot after the PV rebates is $114.)

Designer: Zero Energy Home Plans (Ted L. Clifton)

Builder: TC Legend Homes (Ted W. Clifton)

SIP(SIP) Building panel usually made of oriented strand board (OSB) skins surrounding a core of expanded polystyrene (EPS) foam insulation. SIPs can be erected very quickly with a crane to create an energy-efficient, sturdy home. Manufacturer: Premier SIPs, Fife, Washington

Construction

Foundation: Slab on grade, R-20 horizontal rigid foam insulation beneath, R-10 vertical rigid foam to footing at perimeter

Walls: 6 1/2" SIPs, R-26 including siding and drywall

Roof: 10 1/4" SIPs, R-42 including roofing and drywall

Windows: Vinyltek vinyl windows glazed with Cardinal 180/i81 triple glazingWhen referring to windows or doors, the transparent or translucent layer that transmits light. High-performance glazing may include multiple layers of glass or plastic, low-e coatings, and low-conductivity gas fill. with low-e coatings and argonInert (chemically stable) gas, which, because of its low thermal conductivity, is often used as gas fill between the panes of energy-efficient windows. gas fill. Glazing specs (center-of-glass, not whole window): 0.50 SHGCSolar heat gain coefficient. The fraction of solar gain admitted through a window, expressed as a number between 0 and 1. and U-factors from 0.15 to 0.20, depending on size, configuration, and opening means

Siding: James Hardie HardiePlank fiber-cement siding

Roofing: Pabco Premier asphalt shingles

Space heating: Unico UniChiller air-to-water heat pumpHeating and cooling system in which specialized refrigerant fluid in a sealed system is alternately evaporated and condensed, changing its state from liquid to vapor by altering its pressure; this phase change allows heat to be transferred into or out of the house. See air-source heat pump and ground-source heat pump., 3-ton, 35,400 BTUBritish thermal unit, the amount of heat required to raise one pound of water (about a pint) one degree Fahrenheit in temperature—about the heat content of one wooden kitchen match. One Btu is equivalent to 0.293 watt-hours or 1,055 joules. /h capacity, 9.2 HSPF. Space heat distribution: hydronic PEXCross-linked polyethylene. Specialized type of polyethylene plastic that is strengthened by chemical bonds formed in addition to the usual bonds in the polymerization process. PEX is used primarily as tubing for hot- and cold-water distribution and radiant-floor heating. tubing in first-floor slab. Hydronic heating system is supplemented by electric-resistance in-floor heating mats in upstairs bathroom.

Ventilation: Balanced ventilationMechanical ventilation system in which separate, balanced fans exhaust stale indoor air and bring in fresh outdoor air in equal amounts; often includes heat recovery or heat and moisture recovery (see heat-recovery ventilator and energy-recovery ventilator). system using a Fantech 240-cfm supply fan with HEPA filter, a Fantech kitchen exhaust fan, and Panasonic WhisperGreen exhaust fans. Supply air is delivered to the bedrooms and great room; exhaust air is pulled from the bathrooms, kitchen, and laundry room.

Domestic hot water: Preheated by the air-source heat pumpHeat pump that relies on outside air as the heat source and heat sink; not as effective in cold climates as ground-source heat pumps. and brought up to temperature by electric resistance water heater

Appliances: Energy StarLabeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market; applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners. rated appliances (where applicable), LG front-loading clothes washer and dryer set, Bosch dishwasher, Frigidaire refrigerator, Viking electric range

Lighting: Solatube daylightingUse of sunlight for daytime lighting needs. Daylighting strategies include solar orientation of windows as well as the use of skylights, clerestory windows, solar tubes, reflective surfaces, and interior glazing to allow light to move through a structure., combination of LED can lights and LED and CFLCompact fluorescent lamp. Fluorescent lightbulb in which the tube is folded or twisted into a spiral to concentrate the light output. CFLs are typically three to four times as efficient as incandescent lightbulbs, and last eight to ten times as long. CFLs combine the efficiency of fluorescent light with the convenience of an Edison or screw-in base, and new types have been developed that better mimic the light quality of incandescents. Not all CFLs can be dimmed, and frequent on-off cycling can shorten their life. Concerns have been raised over the mercury content of CFLs, and though they have been deemed safe, proper recycling and disposal is encouraged. Edison-base lights

Energy

Blower-door testTest used to determine a home’s airtightness: a powerful fan is mounted in an exterior door opening and used to pressurize or depressurize the house. By measuring the force needed to maintain a certain pressure difference, a measure of the home’s airtightness can be determined. Operating the blower door also exaggerates air leakage and permits a weatherization contractor to find and seal those leakage areas. results: 0.56 achACH stands for Air Changes per Hour. This is a metric of house air tightness. ACH is often expressed as ACH50, which is the air changes per hour when the house is depressurized to -50 pascals during a blower door test. The term ACHn or NACH refers to "natural" air changes per hour, meaning the rate of air leakage without blower door pressurization or depressurization. While many in the building science community detest this term and its use (because there is no such thing as "normal" or "natural" air leakage; that changes all the time with weather and other conditions), ACHn or NACH is used by many in the residential HVAC industry for their system sizing calculations.@50 Pa

PVPhotovoltaics. Generation of electricity directly from sunlight. A photovoltaic (PV) cell has no moving parts; electrons are energized by sunlight and result in current flow. system: 6.4-kW rooftop PV array (28 Solar World PV modules, each rated at 230 watts), Power One PVI-6000 Aurora String 6-kW inverterDevice for converting direct-current (DC) electricity into the alternating-current (AC) form required for most home uses; necessary if home-generated electricity is to be fed into the electric grid through net-metering arrangements.

Space heat demand: 3.3 MMBtu/yr (1723 BTU/ft2/yr)

Energy used on site (12 months): 6,064 kWh

Energy produced on site (12 months): 7,903 kWh

Net energy balance (12 months): 1,429 kWh surplus

Water Efficiency

• Low-flow plumbing fixtures

• Caroma combination sink and toilet, recycles hand-washing water

• PEX and copper piping

• All storm water handled on site via rain garden and recycled oak wine barrel cisterns

Indoor Air Quality

• No-VOC paints and finishes, hard wax coating on interior wood beams

• Stained concrete slab flooring (first floor), reclaimed wide-plank fir flooring and stair treads with water-based finish (second floor), and tile (upstairs bathroom)

• Balanced ventilation system provides fresh air to living spaces and bedrooms

• Motion-sensor exhaust fan in upstairs bathroom

Green Materials and Resource Efficiency

Regionally sourced reclaimed wide-plank fir flooring (upstairs), fir bar top made from a downed tree, SIPS manufactured 30 miles from site, recycled cast-iron tubs and kitchen sink, low-waste engineering resulted in no dumpster on site during or after construction.

The housing bubble had burst, the banks weren't lending, and we were newlyweds who had no business even thinking about building a custom home, let alone Seattle’s first net-zero house.

By Eric Thomas
We were attracted to an empty south-facing lot, one of the last undeveloped parcels in our neighborhood. Were we naïve to think we could make our dream of an affordable green home a reality?

“Mom and Dad must have paid for that one,” one of our elderly neighbors told me when I met him for the first time.

Lessons Learned

Consider acoustics
During construction, we noticed how footsteps carried from the second floor to the first-floor master bedroom. We asked for fiberglass insulation to be added between the two floors, which helped greatly. However, we didn’t anticipate how vibration from the heat pumpHeating and cooling system in which specialized refrigerant fluid in a sealed system is alternately evaporated and condensed, changing its state from liquid to vapor by altering its pressure; this phase change allows heat to be transferred into or out of the house. See air-source heat pump and ground-source heat pump., carried through the pipes, would make the back wall of the house resonate. We are planning to add flexible rubber hosing from the unit to the exterior wall, but we wished we had paid more attention to sound deadening earlier.

Have your financing in order
Closing on our construction loan was the most stressful and difficult part of the whole process. Most banks were avoiding construction loans at the time. Even after we found a bank that would approve our project, we quickly discovered that the financing process was going to take much longer than we’d expected. The bank asked for more and more documentation and a larger down payment. It came to a head when we received a letter from the seller’s lawyer stating that we would lose the lot if we didn't close within the next week. After countless phone calls and emails, we managed to close just hours before the deadline. Looking back, we wished we had talked to the escrow people we were working with and asked them which banks were lending and, equally importantly, which were quick to close.

Find a trustworthy builder who shares your vision
Despite our best efforts to put every detail of construction in the building contract, the fact is that some things are still subject to the builder’s interpretation. And, for people like us who could never afford an expensive lawsuit, a lot comes down to trust. Luckily, we chose Ted Clifton Jr., our designer’s son, to be our general contractor. When we went to see his work, we fell in love with a pared-down yet refined home he had built for a budget-minded young couple in his Bellingham, WA, neighborhood. We liked how he had used trees from the building site to make massive exposed beams and had made creative use of inexpensive materials that cut costs while giving the house a solid feel and a pleasing look. Knowing that his design sense matched ours gave us peace of mind going into the project, and we were extremely pleased with the results.

Be realistic about DIY savings
In an effort to borrow less money from the bank, we asked our builder if we could lend some sweat equity to the project and even leave some of the upstairs rooms partially unfinished. He was very obliging, but, in the end, the bank was not. After initially approving our DIY plans, the underwriter changed his mind and required that the house be 100% complete. We were still able to do some things ourselves, like paint the trim and install the reclaimed wide-plank fir floors upstairs, but we overestimated the amount of work we would be able to take on and vastly underestimated the time it would take us to complete it, especially since our builder finished a month ahead of schedule. One area where we did save a considerable amount of money was to handle all the permitting and paperwork ourselves.

A marketing copywriter by trade, Eric Thomas founded the Ballard Green Building Talks, is a communications advisor to local environmental and green building groups, and was recently appointed to the Seattle City Light Review Panel. Click here to read Eric's blog.


Eric Thomas

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  1. Bright House Images - www.brighthouseimages.com
  2. Eric Thomas
  3. Ted L. Clifton
  4. Ted Clifton

A Santa Fe Adobe Gets a Modern Addition

Santa Fe, NM

Nov 20 2011 By Michael Grant | 0 comments

General Specs and Team

Location: Santa Fe, NM
Bedrooms: 3
Bathrooms: 3
Living Space : 2400 sqf
Cost (USD/sq. ft.): $250/sqf

Completed August 2010

- Excellence in Green Remodeling from Hacienda's Parade Of Homes (2010)
- Best Design from Hacienda's Parade Of Homes (2010)
- Exemplary Site Utilization from the New Mexico Green Building Council (2010)

Architect/Designer/Builder: Michael Percy Grant,
Percy Home Design, LLC
Structural Engineer: David Grabiel, QPEC

Construction

Roof Type 1: R-49 (torch-down roof over 7" polyiso rigid, unvented)
Roof Type 2: R-56 (standing-seam metal over 2" polyiso over 12" TJI w/ cellulose, unvented)
Walls Existing: R-10 to R-15 (plaster/stucco over 2-3" polyurethane spray foam over 14" earth adobe)
Walls New: R-29 (James Hardie clapboard siding over 2" XPS over 2x6 @ 24 o.c. w/ cellulose)
Floors, existing: 8" inaccessible & uninsulated dirt crawl space, old vents sealed up, exhausted by HRV
Floors, new: R-10 (Concrete slab over 2" XPS throughout, isolated from stem walls for thermal break)
Windows: Serious 725 series windows w/ suspended film glazing (U-0.16) and Pozzi wood-clad windows (U-0.28)

Energy

Passive solar: 250-sf sunroom oriented 16º east of south
5" black slab fully isolated from soil and stem wall by 3" rigid XPS
12" cellulose ceiling plus 1.5" polyiso for R-52 roof

Boiler: Laars Endurance unit for DHW and space heat combined
Heaters: Myson hot water radiant wall heaters
AC: None needed

Water Efficiency

Laundry hoist: Rack that hoists to the ceiling on pulleys to dry clothes; also humidifies our room in our dry climate (see photo)
Rainwater cistern: 1,750-gallon buried tank collecting from 1,500 sf of roof, distributed by a Grundfos pump to drip irrigation
Graywater: Two graywater lines from half of kitchen sink and from master tub, with 3-way diverter valves to feed either landscaping or city sewer in winter

Indoor Air Quality

Whole-house mechanical ventilation: Ultimate Air RecoupAerator HRV runs full time (HRV both provides fresh air and exhausts radon from dirt crawl space)

This addition has a tight envelope, thick insulation, a heat-recovery ventilator, and a roof that harvests rainwater

Michael Grant has been building, renovating, and designing high performance homes in Santa Fe, New Mexico, for almost two decades.

My wife Julia and I stumbled upon this dumpy little adobe home in Santa Fe, NM, which was for rent back in 2003. I thought the place had hidden charm; she was skeptical. After all, it still had double-hung single pane windows that dust could blow through, a smelly gas wall heater, and no insulation to speak of.

Lessons Learned

Like many designers and builders, I have suffered my own slow growth curve and mistakes around building balanced homes: homes that optimize energy performance, spacial function, and artistic form.

My most recent passion is Germany’s PassivhausA residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor. Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is now promoted by the Passivhaus Institut in Darmstadt, Germany. To meet the standard, a home must have an infiltration rate no greater than 0.60 AC/H @ 50 pascals, a maximum annual heating energy use of 15 kWh per square meter (4,755 Btu per square foot), a maximum annual cooling energy use of 15 kWh per square meter (1.39 kWh per square foot), and maximum source energy use for all purposes of 120 kWh per square meter (11.1 kWh per square foot). The standard recommends, but does not require, a maximum design heating load of 10 W per square meter and windows with a maximum U-factor of 0.14. The Passivhaus standard was developed for buildings in central and northern Europe; efforts are underway to clarify the best techniques to achieve the standard for buildings in hot climates. approach, for which I should become a certified designer by next month. My current favorite wall system is a thermal-bridge-free, airtight, high-performance wall consisting of a two-by wood-framed structural inner wall that bears on a raft slab, sheathed to be airtight, and including TJI studs resembling Larsen trusses. The entire wall assembly is then insulated from both sides.

Our home doesn’t have this gorgeous wall system, because I didn’t know about it when we remodeled, which leaves my home, much like me, with room for improvement. But I guess this is also pretty much where I am happy to be.


Michael Percy Grant

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A Deep Energy Retrofit Using Nailbase Insulation Panels

Oak Harbor, WA

May 17 2011 By Peter Yost | 2 comments

General Specs and Team

Location: Oak Harbor, WA
Bedrooms: 2
Bathrooms: 2.5
Living Space : 2900 sqf
Cost (USD/sq. ft.): $100/sqf

Although this per square foot cost does not include the masonry work (done by owner), the cost is well below the "going rate" for new construction in this neighborhood, about $200 per square foot.

HVAC: Barron Heating & Air Conditioning
Energy/Rating Consultant: Pinnacle Inspections
Masonry/Tile: Ward-Johnson Masonry & Tile

Construction

- Foundation: block wall crawl space
- Above-grade wall: 2x4 wood-framed wall
- Roof assembly: Raised-heel truss

Energy

- Foundation: 1st floor, R-38 batt insulation; air barrier sealed floor sheathing
- Above-grade walls: R-29 (4-inch EPS nailbase + high-density fiberglass batts in wall cavity)
- Ceiling: R-38 blown-in fiberglass with 14" raised-heel roof truss
- Windows: Atrium U = 0.28, SHGC = 0.44, VT = 0.46 - 0.56

Water Efficiency

- Low-flow faucets
- Dual-flush toilet (powder room)

Indoor Air Quality

- HEPA filter system
- Rodda zero-VOC paints
- Exhaust fan in garage coupled to door opener and light timer

Green Materials and Resource Efficiency

- 90% recycle rate (commingled off-site recovery)
- Extensive reuse of interior doors
- Extensive continued use of all kitchen cabinets
- Some cabinets reused in garage

Certification

- Energy Value Housing Award, Gold Level Remodel
- Five-star SICBA Built Green®
- Structural Insulated Panel Association Building Excellence Award - Remodel

The use of structural insulated panel (SIP) technology makes for a high-performance “overcoat” for a serious home energy retrofit

Ted Clifton has been building and remodeling homes for more than 45 years. But he continues to recognize good innovations as they come along. That’s why he decided to use nailbase insulation panels on a recent green remodeling project for Bob and Tobie Johnson of Oak Harbor, WA.

What is nailbase insulation?

Lessons Learned

The biggest surprise to Clifton on this project was the crawl space: “The foundation under this house was a crawl space, with unfilled concrete block walls. It was one of the cleanest and driest crawl spaces I have ever seen, so we did the math on whether or not to close it up, or keep it as a vented crawl space. This is the first time in years I have had one come up as more cost-effective to leave as a vented crawl space, partly I think because it had joists deep enough to insulate to R-38. We added the layer of 1/2-in. OSB (3/4 in. in places due to different floor covering thicknesses) to air-seal the existing shiplap board subfloor.”

The other big lesson learned was on the issue of tearing the whole thing down, given that they essentially rebuilt this home from both the inside and the outside. The homeowners first thought that it made more sense to start from scratch, given all of the changes a remodel would entail, but Clifton calculated that he could complete the gut rehab of the home for a fraction of the cost, if, among other things, he used the nailbase insulation panels on the project.

Finally, this from Ted Clifton: "It is very difficult to work around existing masonry fireplaces. Our mason-owners, Bob and Tobie Johnson (Ward-Johnson Masonry & Tile) had a very hard time plugging up all the water leaks and air leaks, but did an excellent job of it in the end."


Peter Yost

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  1. Ted Clifton

The Colorado Chautauqua Cottages

Boulder, CO

May 4 2011 By Peter Yost | 0 comments

General Specs and Team

Location: Boulder, CO
Bedrooms: 2
Bathrooms: 1
Living Space : 500 sqf

The Colorado Chautauqua Cottages range from studios to 3-bedroom units with about 400 to 800 square feet of living space.

Project Manager: Jeff Medanich
The HPP crew:
- Dave Majorowicz
- Brian Hawkins
- Casey Birdsall
- Jeff Strohmeyer
- Steve Watkins
Trade Partners:
- Lind's Plumbing
- Meyer's Heating & Air Conditioning
- Master’s Electric
- EnergyLogic
- ThermalCraft Insulation

Construction

Original:
- Vented, dirt-floor crawlspace
- 2 x 4 uninsulated wood walls
- Vented attic with fiberglass cavity insulation

Post-retrofit:
- Unvented, spray foamed R-12 conditioned crawlspace
- Insulated & air-sealed R-26 wood walls
- Insulated & air-sealed R-40 vented attic

Energy

- Prestige condensing boilers
- Noritz tankless water heaters
- Rinnai wall-mounted space heaters
- Energy Star Panasonic exhaust fans
- Energy Star CFL & LED lighting throughout
- Energy Star ceiling fans
- Tamarack whole-house fans
- BlueLine Energy Monitors

Water Efficiency

- HET WaterSense American Standard toilets
- Low-flow WaterSense Delta H2O Kinetics shower heads
- Low-flow WaterSense Delta faucets
- No dishwasher
- No clothes washer
- Native, drought-tolerant plantings
- ET Weathermatic irrigation controllers

Indoor Air Quality

- Exhaust-only ASHRAE 62.2-compliant mechanical ventilation

Green Materials and Resource Efficiency

- Commingled construction and demolition recycling (65% diversion rate)
- Salvaged framing and attic fiberglass batt insulation
- Green Natura and Amsan Green Solutions housekeeping products

Certification

- 5-star HERS ratings

Jeff Medanich tells the story of preserving the Chautauqua Cottages’ historical character while retrofitting them to high performance

There really is no greater remodeling challenge than green historic preservation. After a 25-year career in East-coast remodeling and then Colorado production homebuilding, Jeff Medanich is tying together all this experience in his green retrofit work at Chautauqua.

A bit of Chautauqua history

Lessons Learned

Chautauqua's Learning Lab encourages both experimentation and sharing results. Here is Jeff outlining what he thinks are the key lessons he has learned from his retrofit work to date:

Using HOBOs
The data loggers we use are Hobo units made by Onset. The model I use mostly logs temperature and relative humidity, and they are set to take a snapshot of those two variables at ten-minute intervals. I have found these devices to be very useful when we are upgrading heating and cooling systems and trying to maintain occupant comfort levels in different spaces within a building. They work well on both our larger buildings and the individual cottages. In several of the cottages that we have converted to the use of wall-mounted, efficient space heaters, the data loggers provide information regarding room temperatures at various locations throughout the cottage and help achieve consistent comfort levels and provide information as to how air is (or isn't) being circulated through the building.

We have also installed two indirect/direct evaporative coolers (Coolerado) in the past two years, and the Hobo units help monitor indoor relative humidity levels as well as temperature. These devices, when used in conjunction with our energy monitors, provide an opportunity to graphically demonstrate the value of taking advantage of Boulder's climate and the value of night-cooling strategies and their effect on energy consumption.

High performance preservation wall assemblies
The nature of our cottages, the way they repeat in design, and our Learning Lab approach provides the opportunity to experiment with various wall assemblies as we conduct our rehab projects. Since we can’t alter the appearance of the cottage exteriors and must we do all our rehab work "from the inside out," we have tried more than one approach to insulate and air-seal from just the inside.

We first experimented with creating a vented air and drainage space between the siding and the insulation through the use of a layer of rigid insulation (see photos). After brainstorming with fellow building scientists at last year's Building Science Summer camp, I decided to try another approach, eliminating the rigid insulation and using Dow Tyvek DrainWrap fastened to the sides of the studs and top and bottom plates, being careful not to attach it to the back side of the siding.

Prior to installing the DrainWrap, we constructed several mock-ups of wall sections and applied various insulation materials, including closed-cell foam and cellulose, to assure that the DrainWrap retained its "wrinkles." This second approach was more cost-effective and provided a continuous drainage plane. To further increase the wall assemblies' R-value and address thermal bridging, we then applied a layer of rigid foam with all seams and edges taped and sealed to create an interior air barrier prior to installing the drywall.

Due to ease of installation, availability of materials, labor and material costs, and performance to date, the DrainWrap wall system is my favorite. We will continue to monitor and observe our retrofitted wall assemblies for any changes.

Tankless water heater performance
Especially with low-flow fixtures, it is easy to “fool” the tankless water heaters with hot water draws too low to trigger the tankless water heater. We have augmented all of our tankless water heaters with a plumbing design that includes booster tanks and sections of larger diameter pipe to promote mixing.


Peter Yost

Tags: , , ,

Image Credits:

  1. Jeff Medanich
  2. Collorado Chautauqua

The ‘Shamrock Shack’ Retrofit – A Family Style of Green

Pacifica, CA

Dec 21 2010 By Peter Yost | 8 comments

General Specs and Team

Location: Pacifica, CA
Bedrooms: 3
Bathrooms: 2
Living Space : 1745 sqf

Interior Design: Alden Miller, Alden Miller Design
Architectural Design & Green Building Consultant: Ann Edminster, Design AVEnues
Contractor: Dan Miller, Daniel Miller Construction
Structural Engineer: Bruce King, Bruce King Consulting
Energy/Mechanical Design: Bill Dakin, Davis Energy Group

Energy

Solar hot water: Heliodyne Gobi 410 solar thermal collectors
PV: 18 Mitsubishi PV-UD185MF5 185-watt modules

• Spray foam insulation added to roof, walls, and floors
• High efficiency Phoenix gas water heater backing up a solar thermal system
• 5 heating zones with programmable thermostats
All new Marvin windows (double low-e, argon-filled) and doors
• Window treatments that modulate solar heat gain and loss
• Grid-tied PV array
• Enclosed stone fireplace to block thermal bridging
• Fireplace replaced with high efficiency Jotul wood stove insert, old chimney sealed
• Energy Star GE refrigerator (GTH22KBRWW)
• CFL, electronic ballast FL, and LED lamps
Sola Tube skylights for natural daylight

Water Efficiency

Bosch (SHV68M03UC) dishwasher
Whirlpool Duet (WFW9400SW) front load clothes washer
Toto Aquia (CST414M), dual flush toilets
Hansgrohe Croma low volume shower heads
• Tub with water saving cross-section
• Remote switch recirculates hot water on-demand to remote bath
• Gray water diversion plumbed in at installation
• Gutters and downspouts designed for catchment and reuse
• Landscaping plan (underway) with native and climate-adapted plants

Indoor Air Quality

Benjamin Moore Natura interior paint low/no VOC
Minwax Polycrylic Clear Satin (water based)
• Cross ventilation and operable windows in all bedrooms
• Doors to outside in 5 rooms

Green Materials and Resource Efficiency

• Reuse of materials (including much of the original wood which was itself reused by Carl McCarthy, the original home’s builder, from demolition of old buildings in San Francisco in 1938 to the early 1940s)
• Salvage of burnable unusable wood for firewood
• Donation of still usable items (Building REsources)
• Minimal volume of demo materials to landfill
• High R-value spray insulation in walls, floors, and ceilings
• All new wood was FSC-certified
• High-volume fly-ash concrete with lower CO2 footprint was used for all new foundation work
• Decorative transparent paneling by 3-form
• RPI 100% HDPE decking

This Bay Area project features family ties to green design and construction spanning three generations

In 1938, Carl McCarthy started his “Shamrock Shack,” a small (700 square feet) weekend retreat overlooking the golf course in Sharp Park (now part of Pacifica), Calif., while he and his wife, Grace, lived 10 miles north in an apartment in San Francisco. He had virtually no building experience and no power tools.

Lessons Learned

Jim and Pat Kremer are really happy with their "new" home. But the performance of their heating system is just not what they were expecting.

Jim Kremer: "Radiant hydronic heat is highly touted and considered to be so green. But we feel it has some drawbacks for our lifestyle and our benign climate. Consider that the system has to heat up the subfloor, the maple hardwood, and in some cases a nice carpet. Under the best of circumstances, this means the lag time to respond is quite long. Unless you keep a room/zone up to temperature full-time, you have to work this lag into the heating program.

"The main living space — living Room, dining room and hallway — are all open and connected. They are served by three PEX zones controlled by one thermostat. I have been using a modest setback at night (at 10 p.m., down to 63°F) and try to heat it up for the morning (by 7 a.m., up to 68°F). Now, when the outside night temperature is in the low 50s, this works OK and it warms OK. But when we got our coldest nights last winter (low 40s — and this is not THAT cold), the system had been unable to get up to temp. Even with progressive recovery set ON with the thermostats, it does NOT bring the space up to heat during the cold snap. And during more normal winter stretches, it is taking 4 hours or more to get up to temp after the setback. If we did NOT set back at night, we could probably keep it at 68°F, but this is certainly wasteful and I am not willing to do that so far.

"The master bath — It is far from the Phoenix water heater/boiler, and the PEX runs along the wall of the Jungle, under the slate floor. It is insulated below, but unless the Jungle is up to temp, the PEX runs quite a ways in the cold slate bed before getting to the bath. So, instead of a small bath area that would heat up quickly, it is slow and very demanding of heat (a large drawdown of the water tank temp — I've monitored it) to warm the floor enough to notice with your toes.

Jim Kremer is determined to optimize the performance of their radiant system. "It's a work in progress; we will learn more about how to tune the system, balancing it's performance with our patterns of use."


Peter Yost

Tags: , , , ,

Image Credits:

  1. Jim Kremer
  2. Alden Miller

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