payback

QA-spotlightheader image

Making the Case for Exterior Foam Insulation

In Climate Zone 3, is installing rigid foam on the exterior side of the wall sheathing worth the effort and expense?

Posted on May 29 2017 by Scott Gibson

Writing from Climate Zone 3, Farm House seems to have worked out many of the details for the dream house he plans to start building in a few months.

"Plan to live in it for 30+ years," he writes in a post at the Q&A forum at Green Building Advisor. "The house will have Zip System 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. and will be well insulated on the inside. I will just leave it at that. Not interested in installing rigid foam on the outside of the roof sheathing. (I have my reasons, so please don't try to convince me otherwise.)


Tags: , ,

Image Credits:

  1. Huber Engineered Woods

guest-blogsheader image

Banish ‘Payback’

Call the money you spend an ‘investment’ rather than ‘costs that must be recovered’

Posted on Oct 13 2016 by Bruce Sullivan

Every conversation about zero-energy homes (ZEHs) eventually comes around to the question of “cost.” The negative connotation of added cost and, even worse, “payback,” always puts ZEH advocates at a disadvantage. For years, I’ve encouraged advocates to call energy expenditures investments rather than “costs that must be recovered.” So, let’s banish the entire idea of “payback” and “payback period.”


Tags: , , , , ,

Image Credits:

  1. Bruce Sullivan

guest-blogsheader image

Number Crunching on a Deep Energy Retrofit

An owner-builder takes a detailed look at how a retrofit added long-term value to his home

Posted on Apr 12 2016 by Christopher Peck

Christopher Peck's original post, The Big Rewards of a Deep Energy Retrofit, was published here on March 15, 2016. That blog and this one both originally appeared at The Resilient Investor.


Tags: , ,

Image Credits:

  1. Joel Schuman

musingsheader image

Solar Hot Water System Maintenance Costs

When you have to shell out a few hundred dollars every time your solar thermal system needs repairs, the maintenance costs will eat into your energy savings

Posted on May 16 2014 by Martin Holladay

I installed my solar hot water system about six years ago. It’s a good system. I have two 4’x8’ AE-32 flat-plate collectors (manufactured by Alternate Energy Technologies), a Superstor Ultra stainless-steel tank (at 80 gallons, it’s a little small, but it’s what I could afford), and an El Sid DC pump from Ivan Labs. Since I installed the equipment myself, it cost significantly less than a professionally installed system.


Tags: , , , ,

Image Credits:

  1. Martin Holladay

QA-spotlightheader image

The Big Allure of Cheap PV

A Connecticut homeowner is tempted by the low cost of solar electricity — but wonders if he should use the money to tighten up the house first

Posted on Feb 10 2014 by Scott Gibson

Until now, Patrick McCombe has believed that improvements to the envelope of his home should come before an investment in photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and result in current flow. panels. Now he's weighing a deal that seems too good to pass up.

McCombe lives in Connecticut (he's an associate editor at Fine Homebuilding magazine) and he recently attended an informational meeting sponsored by an organization working to lower the cost of 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.. Panels could be purchased or leased, but the bottom line was that with federal and state incentives, McCombe could buy a 10-kilowatt array for $15,000.


Tags: , , , ,

Image Credits:

  1. Oregon DOT

QA-spotlightheader image

If We Build It, Will They Come?

A builder wonders why home buyers don’t seem to be embracing super-efficient designs when the benefits are so obvious

Posted on Oct 21 2013 by Scott Gibson

This Q&A Spotlight starts with a simple question from Anders Lewendal, a builder in Bozeman, Montana. If building to the Passivhaus standard is so cost-effective, Lewendal wants to know, why are only a handful of these houses getting built in the U.S. every year?

"Either the cost of fuel is too low or the cost of a 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. is too high," Lewendal writes in a post at Green Building Advisor's Q&A forum.


Tags: , , ,

QA-spotlightheader image

Finding the Insulation Sweet Spot

A builder in Montana wonders whether new tests should be conducted to find the point of diminishing returns for insulation

Posted on Jul 29 2013 by Scott Gibson

Anders Lewendal, a builder in Bozeman, Montana, is wrestling with a familiar dilemma: What's the right amount of insulation to put in a house?

"Our theory," he writes in Q&A post at GreenBuildingAdvisor, "is that too little insulation wastes energy and equally, too much insulation wastes energy. Where is the sweet spot in each climate zone?"

To that end, Lewendal is proposing more performance testing.


Tags: , , ,

Image Credits:

  1. Anders Lewendal

energy-solutionsheader image

Sometimes, It’s Cheaper to Install PV Than More Insulation

Before you decide to add more insulation to your attic, compare the cost of the extra insulation with the cost of supplying the necessary heating or cooling with solar electricity

Posted on Jul 11 2013 by Alex Wilson

There’s an age-old question of how much insulation to install in our homes. Conventional wisdom says to add more until the “payback” for the added insulation isn’t worth it — until the energy savings that will result from the insulation doesn’t pay back the cost of that insulation quickly enough.

Energy and environmental consultant Andy Shapiro, of Energy Balance, Inc. in Montpelier, suggests a different approach: basing that decision on the cost of a solar electric system.


Tags: , , , , ,

Image Credits:

  1. All photos: Alex Wilson

Calculating the Embodied Energy Payback for Passivhaus Buildings

Posted on Jul 19 2012 by mike eliason

A common 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. topic that rears its head every now and again is the embodied energy of construction. While this can be an important issue, we generally feel it’s a moot point for Passivhaus projects – especially the ones we design (owing to better optimized assemblies and less insulation!).


Tags: , , ,

musingsheader image

Payback Calculations for Energy-Efficiency Improvements

How to perform a simple payback analysis and calculate net present value

Posted on Dec 23 2011 by Martin Holladay

If you are considering investing in an energy-efficiency improvement for your home — for example, additional attic insulation or a photovoltaic(PV) Generation of electricity directly from sunlight. A photovoltaic cell has no moving parts; electrons are energized by sunlight and result in current flow. system — you probably expect the investment will lower your energy bills. So it’s only natural to ask, “Is this a good investment?”

For example, let’s say that you are considering spending $5,000 on an improvement that will save you $350 a year on your energy bills. Does the investment make economic sense? The answer, of course, is “it depends.”


Tags: , , ,

Image Credits:

  1. Alexkerhead

Register for a free account and join the conversation


Get a free account and join the conversation!
Become a GBA PRO!

Syndicate content