Green Rating Systems for Home Building

Green Rating Systems With a National Reach — and Some Local Programs

LEED for Homes

LEED for Homes is the Leadership in Energy and Environmental Design program developed by the U.S. Green Building Council.

National Green Building Standard

The National Green Building Standard was facilitated by the National Association of Home Builders and approved in early 2009 by the American National Standards Institute.

EFL Certified Green

Environments for Living Certified Green was developed by a division of Masco Corporation, a construction and home improvement conglomerate.

Local Green Building Programs

In many parts of the country, regional, statewide or local green building programs are better established than the national rating programs.

DIVE DEEPER

Energy Star Just Focuses on Energy

The Energy Star Homes program is run by the U.S. Environmental Protection Agency, not the Department of Energy. It’s limited in scope compared to green-building certification systems, but it remains an important benchmark for energy efficiency and is cited in other rating guidelines.

Energy Star homes are at least 15% more energy efficient than a home that barely meets the 2004 International Residential Code. According to the EPA, an Energy Star house is typically 20% to 30% more energy efficient than a conventionally built house. A more complete description of Energy Star requirements can be found here.

To promote water conservation in new homes, the EPA has launched a companion program to Energy Star called WaterSense. Another companion program, Indoor airPLUS, includes specifications designed to lower risks for indoor mold, radonColorless, odorless, short-lived radioactive gas that can seep into homes and result in lung cancer risk. Radon and its decay products emit cancer-causing alpha, beta, and gamma particles., combustion gases and toxic chemicals. The program mandates more than 30 design and construction features beyond Energy Star requirements.

American Lung Assoc. Health House

The Health House program is sponsored by the American Lung Association.

Health House is focused on healthy interiors. But the national program “fell by the wayside,” in the words of one official, and is now being run only on a regional basis by a Midwest branch of the Lung Association. Officials hope it will be revamped and revived nationally.

PassivHaus Standard is deep green

The Passivhaus standard is a residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low 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. . Developed in the early 1990s by Bo Adamson and Wolfgang Feist, the standard is promoted by the Passivhaus Institut in Darmstadt, Germany and 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. Institute US in Urbana, Ill.

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 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. 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 loadRate at which heat must be added to a space to maintain a desired temperature. See cooling 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.

For more information on the Passivhaus standard, see "Passivhaus for Beginners."

Different Scoring Systems

Each green rating system has a different scoring method. While the maximum number of points under the LEED for HomesLeadership 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. program is 136, the NGBSNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions. allows more than 1,200 points.

The Environments for Living(EFL). A green building program that focuses on building science to improve home energy efficiency and comfort. EFL is administered by Masco Contractor Services. program does not use points to score homes. The standard is performance-based, not prescriptive: a building either meets the standard or it doesn’t.

Of course, the maximum number of points available under a given rating system gives no indication of whether the system is more or less stringent than another system — just as there is no way to compare the value of 5,000 Japanese yen and $800 unless one knows the exchange rate.

ABOUT GREEN RATING SYSTEMS

Getting a label for your house

Green certification can be a valuable marketing tool for builders as U.S. home buyers start to focus more attention on energy efficiency, durability and healthy interiors. Builders who want the advantages of green certification have many options. In addition to the above four programs, dozens of local and regional green building rating programs have been established by local builders' associations. Some have been in operation for more than a decade.

LEED for Homes and the National Green Building Standard (NGBSi) are alike in how they work and what they cover, and at this point, they are probably the two dominant programs in the U.S. Both are point-based systems that rate houses in a number of categories, including water and energy efficiency, resource conservation, and indoor air quality. They require verification by independent inspectors, and both programs grant certification on a four-step scale with progressively more stringent requirements at each step.

Where the programs come from

Commercial buildings came first

LEED was launched in 1998 as a system for measuring sustainable building practices in commercial structures. It has since grown to include houses as well as schools, retail and health care buildings, and neighborhood development.

Both LEED for HomesLeadership 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. and NGBSNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions. are “consensus standards,” meaning they were developed by a diverse group of interested parties rather than written by a single author or entity, and were open to public comment before their adoption. LEED for Homes has not been submitted for ANSIAmerican National Standards Institute. National nonprofit membership organization that coordinates development of national consensus standards. Accreditation by ANSI signifies that the procedures used meet the Institute’s essential requirements for openness, balance, consensus, and due process. review.

Two Paths to Certification

Prescriptive and performance paths

In certain areas, LEED for HomesLeadership 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. , NGBSNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions. and even 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. give builders more than one path toward certification. A “prescriptive” approach is one that tells the builder exactly what steps have to be taken in order for the building to pass muster. This might involve how to install insulation and reduce air infiltration, or which appliances, windows and light fixtures to choose. It’s a checklist.

In contrast, a “performance” approach tells the builder what the building must do to pass. It leaves decisions of how to get there largely, although not entirely, up to the builder.

A prescriptive standard tells you what to do
A good example of how this works can be found in Energy Star. Under the prescriptive approach, which is called the Builder Option Package, Energy Star specifies the energy efficiency of heating and cooling equipment, the type of thermostat to be used, duct and 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. leakage, and lists specifications for windows, water heaters and lighting fixtures.

A performance standard tells you what your goal is
Under the performance-based method, the builder gets to decide how to achieve energy savings. In the end, houses must attain a 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 of either 80 or 85 depending on what climate zone they’re located in, plus pass a ductwork and envelope inspection. (The HERS Index is a 100-point scale describing the energy efficiency of the house. A house built to the 2006 International Energy Conservation Code would score 100. A net-zero house would score 0. Every 1-point drop in the Index corresponds to a 1% decrease in energy consumption).

LEED for Homes and the NGBS both offer this prescriptive or performance option in the area of energy efficiency. Environments for Living(EFL). A green building program that focuses on building science to improve home energy efficiency and comfort. EFL is administered by Masco Contractor Services. offers a single track for compliance.

What LEED and NGBS are looking for

You Need Points In Each Category

LEED for HomesLeadership 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. and NGBS divide the process of building a house into a number of different phases or components, beginning with development of the lot and ending with homeowner education. Builders get points for reaching certain performance or construction goals in each section that count toward the project’s total and, ultimately, its level of green certification.

Generally speaking, the areas concern site development, resource efficiency, energy efficiency, water efficiency, indoor environmental quality, and operations and education. The categories are roughly similar, although not identical. For instance, what LEED for Homes calls “materials & resources” is “resource efficiency” in the NGBS; “energy & atmosphere” in LEED for Homes is “energy efficiency” in the NGBS, and so on. LEED for Homes has a total of eight categories. NGBS has six.

Scoring systems differ
There are some substantial differences. One is how many points are available overall—136 in LEED for Homes and more than 1,200 in NGBS. That means the thresholds for corresponding levels of certification are different, along with the relative weight that each point has. For example, it takes 60 points under LEED for Homes to reach “silver” status. Under the NGBS, a builder would need a minimum of 406 points.

Builders also win points in slightly different ways. Under NGBS scoring rules, of the 406 points needed for silver, 79 (19.5%) have to come in resource efficiency, 60 points (14.8%) in energy efficiency, and 26 points (6.4%) in water efficiency. The project also would also have to accumulate 100 points, about 25% of the total, in other categories the builder chooses.

Adjusting Point Thresholds for House Size

LEED for Homes lowers the minimum number of points required for each rating category for homes that are smaller than average, and raises the threashold for homes that are larger than average. Under LEED for Homes, a 900-square-foot house with one bedroom is defined as an average-sized house. An average-sized two-bedroom house is 1,400 square feet; a three-bedroom house, 1,900 square feet; a four-bedroom house, 2,600 square feet; and a five-bedroom house, 2,850 square feet. Houses that exceed these thresholds need extra points.

Documentation and Fees

From about $900 to about $2,500

In very general terms, getting a house certified as green follows a similar path under LEED for HomesLeadership 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. and NGBSNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions. . The builder is charged a per-house fee for certification and pays separately for performance verification by an independent evaluator whose rates are not standardized. Both programs offer a volume discount.

Third-party verification
In the case of NGBS, “verifiers” accredited by the NAHBNational Association of Home Builders, which awards a Model Green Home Certification. Research Center carry out the inspections. By early 2009, there were 335 verifiers nationally. For LEED for Homes, “green raters” do the field inspections. They work through local and regional providers recognized by the U.S. Green Building Council. LEED for Homes requires early collaboration with a provider; NGBS does not.

NAHB charges $500 per house (discounted to $200 for NAHB members) to enroll in the NGBS program, and estimates that verification fees should cost an additional $700 to $1,200, for a total of $900 to $1,400 per house. (Costs decline sharply for builders who certify more than 500 houses per year.)

Charges for LEED for Homes certification include a $150 registration fee, $225 for certification and separate charges for plan review and field verification.

Prices may vary
The U.S. Green Building Council says each LEED provider sets its own documentation and verification fees. “The cost of verification will vary with size of the home, the certification level sought (i.e. Certified, Silver, Gold, Platinum), travel time required by the rater, the number of homes being built and the builder’s experience with green homebuilding techniques,” LEED says.

How the fees play out depends very much on where the house is located and the particulars of the project. Armando Cobo, a former builder and now a house designer in Albuquerque, New Mexico, has used both LEED for Homes and Build Green New Mexico guidelines, which are based on the old NAHB system. He builds custom homes to “silver” ratings or higher and says costs for certifying a Build Green home are between $1,500 and $1,700 while a LEED for Homes house costs between $2,200 and $2,500.

Although builders and designers in other areas may have very different experiences, LEED for Homes is typically the more expensive option.

Are the systems really very different?

For an entry-level home, choose NGBS

One obvious question is how the various rating systems would treat the same house. Is one tougher than another? If a house scores as gold on the NGBS scale where would it fall on the LEED scale? Could an EFL house be certified under either of the other two big national programs? Do consumers really care who certifies the house?

Highest rungs are comparable
Answers to all of those questions depend on whom you ask. A common refrain in the green-building business is that LEED certification appears harder to win at the entry level but that NGBS and LEED for HomesLeadership 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. are roughly comparable at the top levels (emerald and platinum).

Because LEED and NGBS both give builders some leeway, there is no single spec for houses that can be certified. To some degree, builders can favor one point category over another and still get a certified house, as long as they meet any program minimums. One certified house might rack up more landscaping and site points, another more energy conservation measures.

“NGBS has a low entry-level bar”
Here are several points of view:

“LEED would laugh at an ANSIAmerican National Standards Institute. National nonprofit membership organization that coordinates development of national consensus standards. Accreditation by ANSI signifies that the procedures used meet the Institute’s essential requirements for openness, balance, consensus, and due process. standard bronze house as being pathetic greenwashingDissemination of misleading or false information designed to make an organization or product appear more environmentally friendly than it actually is.,” says North Carolina builder Michael Chandler of Chandler 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.. “But I think most LEED people would look at what’s required for silver and say, ‘Yeah, that’s a pretty decently well built house.’”

“Basically it’s the same,” says New Mexico’s Armando Cobo. “Based on our experience here in New Mexico, overall we could tell that both of the programs are very compatible with one another. … If you were to take 50 different projects and analyze them, I guarantee that you’re going to be within 1% or 2% from one program to another. And that’s a good thing because now it’s brought in both programs to an even playing field.”

Kevin Morrow, NAHB’s green building program manager, says the greater number of line items in NGBS provides more flexibility for builders because there are more ways to gather points for certification. This also helps builders adapt to regional or local conditions, Morrow says. Builders can choose performance goals that make sense for a specific locale. In the desert Southwest, a builder might use more discretionary points on water conservation while his counterpart in New England might be more interested in seeking extra points for energy efficiency.

“NGBS is more flexible”
“It really becomes difficult to compare the two programs,” Morrow says. “They’re quite frankly apples and oranges. They’re similar in spirit in that they’re out to address the same basic requirements in the same basic categories of green building. In fact, in a lot of ways the chapters are separated similarly if not the same. But in terms of weighted points and measures, the Standard has a lot more line items to choose from whereas LEED for Homes has fewer line items overall, a higher percentage of required or mandatory line items and much fewer areas of builder choice credits.

“I think generally speaking you could probably say that they track fairly closely,” Morrow continued. “But are they true to cross-scoring? No, I don’t think you could make that conclusion.”

Green guidelines are the least stringent option
If the NGBS and LEED for Homes are closer in intent, both leave the older NAHB guidelines far behind. “While the guidelines are a great tool, they probably could have been a better tool,” says Don Ferrier, a custom green homebuilder in the Dallas-Fort Worth, Texas, area. “They could have been more stringent, more thorough and required more verification, so the Standard is really a more heavyweight version of the guidelines.”

That leaves Environments for Living(EFL). A green building program that focuses on building science to improve home energy efficiency and comfort. EFL is administered by Masco Contractor Services., not as widely known and more focused than either of the other two. However good an EFL Certified Green house might be from an energy, durability or indoor air quality standpoint, it could not win even a basic certification under either LEED for Homes or NGBS. EFL does not have any requirements for either site development and management, or homeowner education. Both LEED for Homes and NGBS list point requirements for site development.

Who are the programs really trying to reach?

Complementary Programs, Not Rivals

There are certainly some differences in the fine print between green-rating systems. Chandler and others, however, also see a contrast in what the programs are trying to accomplish and whom they’re trying to target.

Green evangelists welcome all comers
The new ANSIAmerican National Standards Institute. National nonprofit membership organization that coordinates development of national consensus standards. Accreditation by ANSI signifies that the procedures used meet the Institute’s essential requirements for openness, balance, consensus, and due process. standard and its NAHBNational Association of Home Builders, which awards a Model Green Home Certification. predecessor are “evangelical” programs aimed at getting builders to think about houses in a different way, Chandler says. “Whereas LEED is a program aimed at higher performance, well-established luxury homebuilders aiming to differentiate themselves from other luxury homebuilders.

“The idea is we’re trying to reach out to people who are just now building 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.,” he adds. “Green building is all about systems approaches. You don’t just take the energy and forget about the indoor air quality and the humidity and the durability and the homeowner education. You’ve got to take them all together as a systems approach. What we’re really working at in the ANSI standard [NGBSNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions. ] is to get people to go beyond Energy Star. It’s mainly about changing the way builders think about houses and systems so they start to see the big picture, see that each part of the system affects every other part of the system.”

Chandler is fan of the NAHB programs, in part because they will help make sustainable building affordable to a greater number of homebuyers. In that sense, NAHB efforts are more in keeping with Masco’s aim to make green building a “value proposition” for builders who might be wary of a huge investment in green.

“Both programs are necessary”
Ann Edminster, a California consultant and architect who was the chief author of the LEED for HomesLeadership 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. rating system, thinks NAHB’s effort to reach a larger number of builders is important.

“More units with smaller incremental changes, but potentially drawing in a much larger fraction of the building population — is that the greener position? I think arguably it is,” she says. “We need both that and LEED. In my view all of these programs are complementary and mutually supportive and reinforcing. Yeah, the NAHB sets a lower bar, but that’s not a critique. I think that’s a deliberate, strategic stance that they took that’s an extremely valid and important one in terms of market transformation.”

“It’s not elitist”
But she disagrees with the notion that LEED for Homes is only for luxury homebuilders. The committee originally working on the LEED for Homes program, Edminster says, was adamant that it could not be “an elitist, boutique program.” And in the end, green building has proved more of a challenge for the middle of the socio-economic scale, not the top or the bottom.

“A lot of entities that either fund or in other ways regulate or approve the creation of affordable housing subsidized housing have mandated green building measures in response to social equity issues associated with poor-quality affordable housing in the past,” Edminster says.

“Because it’s created a level playing field for all developers of affordable housing, they have to build green. Well, if everybody has to then all of a sudden it’s no longer, quote, expensive anymore. It’s part of what you do to get a building built.”

FURTHER RESOURCES

Comparing Green Building Rating Systems

An overview of green rating systems from Smart Communities Network.

An overview of green rating systems from the perspective of remodelers.

The ReGreen Program Web site explains the ReGreen label for remodeled homes.

An overview of green rating systems from a Pacific Northwest perspective.

An overview of green rating systems from a Florida perspective.


Residential Construction Waste Management: A Builder's Field Guide
is a free 30-page booklet available from NAHB.

A Web site with Construction Site Recycling Tips is maintained by RecycleWorks, San Mateo County, Calif.

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2.
Wed, 01/25/2012 - 18:38

Green Rating Systems for Home Building
by Armand Magnelli

What about Green Communities? www.enterprisecommunity.com Its focus is affordable housing, but it is a sophisticated standard that is less costly than LEED to certify.


1.
Wed, 05/25/2011 - 17:07

One That's Missing
by Drew Steves

Earth Advantage Institute in Portland, Oregon has been around since 2000 and has certified over 10,000 homes. "The dream of the 90's is alive in Portland..."


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