National Green Building Standard

After Years in Committee, We Have a Green Building Standard

NGBS

A consensus forged among industry stakeholders

Representatives from a variety of building professions, including the International Code Council, developed the new standard. The proposal went through a lengthy development process before it was submitted to the American National Standards Institute for review. 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. approved the standard in February 2009, thus positioning it for eventual adoption by municipal or state governments as part of their building codes.


Lot

Lot Design and Preparation

Among the actions that yield points in this category: selecting a lot within 5 miles of a mass transit stop equipped with parking; providing walkways that promote pedestrian activity; providing a supervisor with basic training in tree protection; selling cleared trees for pulp; and improving soil with organic amendments.

5 points for bronze
66 points for silver
93 points for gold
119 points for emerald


Resources

Resource Efficiency

Houses between 2,501 and 4,000 sq. ft. are "point neutral."

Houses smaller than 2,500 sq. ft. are awarded points, while houses larger than 4,000 sq. ft. need to achieve additional points.

The size-adjustment factor works as follows:

  • Homes measuring 1,000 sq. ft. or less get 15 points;
  • Homes between 1,001 sq. ft. and 1,500 sq. ft. get 12 points:
  • Homes between 1,501 sq. ft. and 2,000 sq. ft. get 9 points;
  • Homes between 2,001 sq. ft. and 2,500 sq. ft. get 6 points.

For every 100 sq. ft. over 4,000 square feet, builders must obtain one additional point in Category 7 for each performance level.

45 points for bronze
79 points for silver
113 points for gold
146 points for emerald


Energy

Energy Efficiency

Home that qualify for an 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. label fulfill bronze-level requirements for Energy Efficiency.

Buidlers can meet Energy Efficiency requirements by either the performance path (15% better than IECC International Energy Conservation Code.) or the prescriptive path.

The prescriptive path requires builders to obtain 30 points in Section 703 of 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. (covering practices like insulation installation quality, air barriers, and windows) and 2 practices from Section 704 (for example, hard-wired Energy Star lighting fixtures or Energy Star appliances).

30 points for bronze
60 points for silver
100 points for gold
120 points for emerald


Water

Water Efficiency

Among the water-saving measures that yield points:

  • Low-flow (1.28-gallon-per flush) toilets (6 points per toilet, 18 points max.)
  • Rainwater collection system (6 points)
  • Composting toilet (24 points)
  • 14 points for bronze
    26 points for silver
    41 points for gold
    60 points for emerald


    IEQ

    Indoor Environmental Quality

    Keeping the furnace or air handler out of the garage is worth 5 points. Avoiding atmospherically vented space heating or water heating equipment within the conditioned spaceInsulated, air-sealed part of a building that is actively heated and/or cooled for occupant comfort. is worth another 5 points, while a direct-vent furnace or boiler within the conditioned space gets you an additional 5 points.

    Other measures yeilding points in this category:

    • Direct-vent gas fireplace with gasketed doors,
    • Carbon monoxide alarms,
    • Ducting the range hood to the outside,
    • An energy-recovery ventilator(ERV). The part of a balanced ventilation system that captures water vapor and heat from one airstream to condition another. In cold climates, water vapor captured from the outgoing airstream by ERVs can humidify incoming air. In hot-humid climates, ERVs can help maintain (but not reduce) the interior relative humidity as outside air is conditioned by the ERV. or heat-recovery ventilator(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. .

    36 points for bronze
    65 points for silver
    100 points for gold
    140 points for emerald


    Education

    Operation and Homeowner Education

    Four different manuals are worth 1 point each:

    • A building construction manual (including a green building narrative)
    • A building owner's manual (including manufacturers' manuals)
    • A building operation manual (including a list of practices to conserve water and energy)
    • A maintenance manual (including information on changing filters, water heater settings, etc.)

    A builder who provides face-to-face homeowner training can receive an additional 6 points.

    8 points for bronze
    10 points for silver
    11 points for gold
    12 points for emerald


    Extras

    Additional Required Points from Any Category

    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. notes that "the additional points prescribed in Category 7 shall be achieved from any of the categories."

    For houses greater than 4,000 square feet, the number of points needed in this category is increased and the total points required are also increased by the same number of points.

    50 points for bronze
    100 points for silver
    100 points for gold
    100 points for emerald


    NAHB’s Model Green Home Building Guidelines

    NAHB’s Model Green Home Building Guidelines are a less stringent predecessor to the National Green Building StandardNational 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 Guidelines were introduced in 2005 to help NAHB’s 800 affiliate builder organizations develop local programs.

    The Guidelines became the starting point for the new standards when NAHB sought to develop its own standardized green-building certification rules. The Model Green Guidelines gave NAHB affiliates around the country a place to start, and a number of regional programs took root because of them.

    The Guidelines will remain available to builders, but they aren’t likely to get a huge amount of attention from NAHB in the future. Eventually, expect them to fade from view.

    ABOUT THE NATIONAL GREEN BUILDING STANDARD

    The National Green Building Standard, also known as ICC-700, grew out of NAHB’s earlier Model Green Building Guidelines. 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. includes a number of mandatory practices, none of which are worth any points toward certification. Many are in the energy efficiency area and include requirements for caulking or otherwise sealing windows and doors, insulating skylight shafts and kneewalls, using airtight, IC-rated recessed lighting fixtures and running Manual J calculations for sizing heating and cooling equipment.

    SHADES OF GREEN

    The NGBS has four compliance levels. While 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. calls its levels certified, silver, gold, and platinum, NGBS uses the terms bronze, silver, gold, and emerald.

    Builders must accrue points by incorporating features in six areas: site development, water conservation, energy conservation, resource conservation, indoor air quality, and homeowner education. Houses over 4,000 square feet will need more points for a given certification level than smaller houses.

    NGBS requires progressively more points in the energy-efficiency category to climb the ladder from a bronze to an emerald rating, starting at 30 points at the bronze level and going to 120 at emerald. A number of mandatory measures also must be met, for which no points are awarded. On the alternative performance path, at the bronze level the house must be 15% more efficient than a house built to the 2006 International Energy Conservation Code (the same as an 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. qualified home). For silver, it increases to 30%; gold, 50%; and emerald, 60% better than IECC International Energy Conservation Code..

    All houses must include a mechanical ventilation system complying with ASHRAEAmerican Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). International organization dedicated to the advancement of heating, ventilation, air conditioning, and refrigeration through research, standards writing, publishing, and continuing education. Membership is open to anyone in the HVAC&R field; the organization has about 50,000 members. Standard 62.2.

    REGIONAL DIFFERENCES

    Although energy compliance depends strongly on climate zone, most ICC-700 checklist points (including water-saving measures) apply nationwide. There are a few exceptions, however; as Don Carr, NAHB’s national green building certification program manager, pointed out, “The standard includes a termite zone map, a 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. map, and rainfall map.”

    ONLINE SCORING TOOL

    The NAHB Research Center has established a process to certify whether projects meet 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. . The first step is for builders to use NAHB’s free online scoring tool. “The scoring tool sets us apart from our competition,” explained NAHB division director Vladimir Kochkin. “It simplifies implementation. When you get a score, so you can see what level you qualify for. Then you can make changes; you can play around with it. If you decide to go for certification, you fill out an application, which is submitted to an outside NAHB-accredited verifier. The verifier will look at the information submitted. Then, to make sure that that the construction is consistent with the information in the application, the verifier will conduct two on-site inspections: a rough-in inspection and a final inspection.”

    NAHB charges builders $500 per project for certification; the fee drops to $200 for NAHB members. In addition to the certification fee, builders will need to pay several hundred dollars for third-party verification.

    COMPARING STRINGENCY

    Since the NGBS is brand new, it will take a while for energy consultants to determine whether the standard is more or less stringent than 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. . “My opinion right now, subject to confirmation from additional study, is that the basic ICC-700 standard house will be very close to a LEED for Homes certified house,” said Bion Howard, an energy consultant from Valley Center, California. LEED takes a tougher line on certain divisive issues, however, such as certification of tropical woods.

    According to Carr, “Compared to LEED for Homes, I think builders will find that NAHB’s green building standard is more flexible and usually less expensive to meet in terms of hard costs. And it is definitely less expensive to meet in terms of soft costs.”

    When comparing the new standard with the old NAHB Guidelines, NAHB representatives are unequivocal. “The Standard is more stringent than the Guidelines,” said Carr. “The bar has been raised.” Kochkin agrees. “At the end of the day they ratcheted up the Standard compared to the Guidelines quite a bit,” said Kochkin. “The new Bronze corresponds more or less to the silver level in the Guidelines.”

    AN INSIDE TRACK FOR WIDESPREAD CODE ADOPTION

    BUILDERS WANTED A LOWER BAR THAN LEED FOR HOMES

    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. approval of the NAHBNational Association of Home Builders, which awards a Model Green Home Certification.-inspired standards, which were developed with the help of the International Code Council, brings green building one step closer to wider adoption by state and local governments.

    Ready for code adoption
    The standard is already written in code-speak. A local governmental agency could ramp up to mandatory green building virtually overnight because the standard is ready to go — compatible with the International Residential Code and with the ANSI stamp of approval. This will leave LEED for Homes, EFL and other rating systems an optional and probably less-traveled path. And that’s apparently just what NAHB had in mind.

    Ray Tonjes, an Austin, Texas, builder who helped develop the original NAHB green building guidelines, summed it up this way: “The intent was that the standard be voluntary, but I’m sure it will in some municipalities and some states become mandatory and that’s a big reason why NAHB went through this process, so that it had the credibility of a standard and it would be a credible code if that’s what happens.”

    To make the transition, start at the bottom rung
    For NAHB, helping a less aggressive green building standard through to code readiness was a service to its builder members, especially those who didn’t have a lot of green building experience under their belts. Moving from simple code-compliant houses to LEED for Homes certified houses might seem like a big step all at once. Getting to the lower rungs of 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. certification should be easier and less expensive.

    “Ultimately, LEED for Homes allows broader interpretation of actions and specifications that might earn the rating points and a measure of freedom in selection of environmental performance areas,” according to an analysis of the competing rating systems prepared by the NAHB Research Center. “This type of flexibility is ideal for more experimental green home designs.”

    Keeping mainstream builders in mind
    That is in keeping with the U.S. Green Building Council’s target market of the nation’s top 25% builders, the report adds, while the original NAHB guidelines and then the NGBS were developed with the mainstream builder in mind.

    “The standard that we’re talking about just puts [green building] into the same administrative process that we are used to doing with the code, and I don’t see how you can possibly find fault with that process,” Tonjes says. “If you think about it, building a green house is no different than dealing with any other kind of specifications you’ve got in the house. The ANSI standard and the national scoring tool put it into the normal building process. That was the motivation for NAHB, to provide that service to its members.”


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