New Houses are So Last Year

Build It Green recently launched its newest program - GreenPoint Rated Existing Home.

January 03, 2009
January/February 2009
A version of this article appears in the January/February 2009 issue of Home Energy Magazine.
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GreenPoint Rated Existing Home is the nation’s first comprehensive third-party rating system for evaluating the environmental impact of existing and remodeled homes. The existing homes program is modeled after the highly successful GreenPoint Rated New Home rating system, which launched at West Coast Green in 2006, and currently has 6,000 homes enrolled in the program, with another 7,000 in the pipeline. In addition, 70 city and county governments have tied to the new homes program for their green building ordinances, and it has been endorsed by multiple regional home builder organizations, and the California Air Resources Board. The new rating system for existing homes is compatible with state and national standards such as the California Energy Commission (CEC) HERS Phase II, Home Performance with Energy Star (HPwES), and many of the Building Performance Institute (BPI) energy evaluation programs. GreenPoint Rated Existing Home will help upgrade our existing housing stock in a way that is environmentally beneficial and marketable, by capitalizing on one of the most sustainable building practices we have—reuse.

The Opportunity  

As California tackles its ambitious
goals for energy efficiency and
greenhouse gas reduction, existing homes have been
a major focus.
California has one of the most progressive energy codes in the country; the state was recently awarded the highest score on the American Council for an Energy Efficient Economy (ACEEE) 2008 State Energy Efficiency Scorecard. Title 24 Part 6 of the California Building Code sets stringent requirements for new homes and major remodels. Homes built under the California Energy Code are approximately 15% more energy efficient than homes built elsewhere in the country. These requirements bode well for new construction in California, but do not address the 70% of California’s housing stock built prior to 1980 and the adoption of the Title 24 Energy Code. Unless they were recently remodeled, these homes are not likely to have wall or attic insulation, and most have 3+ gallons per flush (gpf) toilets, electrical systems that may not conform to current code, and outdated HVAC equipment. Clearly, existing homes can make significant gains in those areas addressed by Title 24 as well as other segments of green building.

As California tackles its ambitious goals for energy efficiency and greenhouse gas reduction, existing homes have been a major focus. With the passing of Assembly Bill 32, which targets a state reduction of CO2 emissions to 1990 levels by 2020, California has taken a hard stance on cutting CO2 emissions. Using the building sector, and including the remodeling industry, is a primary strategy to help meet these goals. In addition, the California Public Utility Commission’s 2008 Strategic Plan calls for new net zero energy homes and a 40% improvement of the existing home stock by 2020. GreenPoint Rated Existing Home provides a mechanism for meeting these state goals, and Build It Green has begun collaborating with key stakeholders in the industry to make these objectives a reality.

GreenPoint Rated Existing Home measures the performance of an existing or remodelled home in the five key environmental categories of Community, Energy, Indoor Air Quality, Resource Efficiency, and Water. The goal is to provide homeowners with a label they can trust. The GreenPoint Rated label adds value to the home; it gives owners confidence that their home is not only more resource efficient, but also more comfortable and healthy. David Gottfried, CEO of Regenerative Ventures and founder of the U.S. and World Green Building Councils, describes his recent experience with the program:

Having my home certified as a GreenPoint Rated home offered me the opportunity to ensure that the specified green energy systems were installed correctly and performed as the manufacturer intended. Having the thorough and knowledgeable GreenPoint rater and home performance contractor inspect and verify that the appliances and heating and ventilating systems were operating at their optimal performances was an invaluable asset. During the rating process, the GreenPoint rater found several items that were not operating as intended and identified air leaks in the home that would have resulted in less comfort and higher energy bills. Had we not gone through the GreenPoint rating program, we would not have been able to identify and address these problems quickly and easily.

Two Tiers of Labels

GreenPoint Rated Existing Home provides two tiers of labels, the Elements label and the Whole House label. The Elements label is for homes undergoing a minor remodel, and for homes undergoing a full remodel over an extended period of time (see “Elements Case Study”). The Whole House label is for homes undergoing a comprehensive upgrade, and for recently built green homes that did not participate in the GreenPoint Rated New Home program (see “Whole House Case Study”). Both tiers are graded in five GreenPoint Rated environmental categories and require projects to meet minimum point thresholds in four key categories (Energy, Indoor Air Quality, Resource Efficiency, and Water) as well as meeting total point thresholds and the program prerequisites. Both tiers serve to educate homeowners, providing them with information about the environmental benefits of the improvements they have made, and, in the case of Elements projects, a road map to additional improvements they could make in order to receive the Whole House label.

The thresholds for participating in the Elements program have been scaled to reflect the smaller scope of Elements projects. The minimum point total is 25, with additional thresholds in the four key categories. Elements projects must complete a set of four prerequisites in order to participate. These include passing a combustion safety backdraft test; having no plumbing leaks; recycling all cardboard, concrete, and metal (for projects undergoing a remodel); and undergoing a basic HVAC and thermal envelope evaluation. Points in the Energy category are derived from a prescriptive list of measures, such as increasing insulation values, sealing ductwork, and installing Energy Star appliances.

The Whole House program has a more strict set of requirements, with a minimum point total of 50, and  higher thresholds in the four key categories, as well as eight, rather than four, prerequisites. These include the four prerequisites required for the Elements label, plus four more: bringing plumbing fixtures up to the Federal Energy Policy Act of 1992 (EPAct 1992); conducting CO testing and correction; repairing any water intrusion sources; and meeting an energy budget (discussed below). The gains can be significant, regardless of which program the house qualifies for. For example, a pre-1980 home that qualifies for the Elements label is likely to see an increase in energy efficiency of at least 5%–10% as a result of meeting the energy points requirements, whereas a pre-1980 home meeting the computer modeled energy budget for Whole House will show an increase in energy efficiency of at least 37%. The home described in the sidebar “Whole House Case Study” saw a 62.1% improvement over the California Energy Commission’s default home for the same vintage in the same area.

Calculating the Energy Budget for a Whole House rating requires a comprehensive performance-based energy evaluation and upgrade. In order to receive the Whole House rating and consumer label, a home must meet or beat an energy budget based on the GreenPoint Rated Existing Home energy thresholds for its age. The energy budget is calculated with performance inputs such as diagnostic testing and equipment efficiencies, in addition to some prescriptive measures, such as installing Energy Star appliances.

Points are given for performance metrics that meet the budget, with additional points for exceeding the budget. There are four Energy Vintage thresholds, categorized by standard California construction practices in four different eras. These are pre-1980, 1980–2000 (the advent of Title 24), 2001 Title 24 Energy Code, and 2005 Title 24 Energy Code. To receive the Whole House label, the house must meet or beat a budget based on the threshold for the era in which it was built.

The house is modeled in an Energy Pro modeling software package comparable to those designed to calculate Title 24 requirements for new homes (see “Fixing California's Existing Homes,”  HE Nov/Dec ’08, p.16). Individual upgrades to the building envelope (such as added insulation) and the mechanical system are not awarded individual points; instead, they are input into the modeling software. The software inputs are based upon the draft version of the California Energy Commission’s HERS Phase II protocols for the evaluation of existing homes, and will be updated to match the final version adopted by the state. These protocols include some appliance and lighting loads, and closely match the HERS index system used nationwide, except that these protocols use time-dependent valuation (TDV) evaluations.

Training and Certifying Raters

To implement the program, Build It Green has tapped its growing pool of nearly 300 certified GreenPoint raters throughout the state of California. These building professionals have been trained to become third-party verifiers for GreenPoint Rated New Home and have passed a rigorous building plan review and field examination (see “California’s Green Rating System,” HE, Sept/Oct ’07, p. 28). From this group, subsets of third-party raters have gone on to complete the Existing Home course for certification. This training requires the GreenPoint rater to have prior experience with HERS rating or home performance testing in addition to a working knowledge of current and vintage construction methods and a sound understanding of building science.

Many raters certified for Existing Home are associated with professional organizations already familiar with home upgrades, including the California Building Performance Contractors Association (CBPCA), the National Association of the Remodeling Industry (NARI), and the California Real Estate Inspection Association (CREIA). Once certified, Existing Home raters act as verifiers and educators for the GreenPoint Rated Existing Home system.

The rater meets with the homeowner or builder to establish a project scope and to determine which of the two tiers, Whole House or Element, is most appropriate. This is a great educational process for the homeowner, as John Eckstein, an Existing Home rater, points out, “I am excited about the Existing Home program because it is much more than a rating program. Existing Homes will motivate homeowners to make better choices about how they build, remodel, maintain, and live in their homes. Its potential extends beyond rating—it is as much a tool for homeowners to understand where a home stands today as it is a path for where they can go tomorrow.”

Once the rater and homeowner have established a preliminary checklist for the project, the rater sets about coordinating with the appropriate parties, including the remodeling contractor, subcontractors, and home performance contractors, to make the necessary verifications. If the homeowner is seeking a Whole House rating, the rater will be responsible for completing the energy budget as described above. The rater is then responsible for making the required submissions to Build It Green in order to complete the rating.

Next Steps

When Build It Green was in the final stages of designing the Existing Homes rating system, it asked a group of GreenPoint raters with extensive home performance experience to participate in a pilot program to help identify areas for improvement and refine the system. Twelve homes participated in the pilot, with a mixture of Whole House and Elements projects. These pilots helped finalize the program. Following the official launch of the program, Build It Green offered a second GreenPoint rater Existing Home training course, and certified Existing Home raters throughout the state.

Looking forward, Build It Green is in the process of developing a Web-based tracking system, which will include a climate calculator tied to GreenPoint Rated, allowing projects to quantify emissions reductions. Also in development is GreenPoint Rated Existing Home for Multifamily housing units, to launch in the second quarter of 2009. A full schedule of New Home and Existing Home GreenPoint rater trainings is planned for 2009.

The California Public Utilities Commission’s (CPUC) strategic plan calls for new net zero energy home construction by 2020. But the more daunting goal is to remodel 25% of the existing home stock to consume 70% less purchased energy by 2020 than it consumed in 2008, and to remodel the other 75% to use 30% less purchased energy than in 2008 by 2020. California has 13.2 million existing homes, which, given the CPUC’s goals, represent a massive environmental challenge—or opportunity, depending on how you look at it. The goals have been set, but the mechanism for meeting them has not been outlined. By using third-party verification and diagnostic evaluations to test true home performance, Build It Green stands to be the instrument by which California can meet the lofty goals it has set for statewide energy reduction. At the same time, Build It Green can provide a consumer label homeowners can trust, and a marketing tool builders can use to distinguish their work.

Corey Fitch is a GreenPoint Rated program associate at Build It Green, where he helps to train and support raters, helps develop green building protocols, and consults with builders. He is a certified GreenPoint rater, a HERS rater, and a member of the California Building Performance Contractors Association (CBPCA). Prior to his work at Build It Green, he spent two and a half years working on sustainable development and alternative energy projects in the Philippines.

For more information:
For more information about GreenPoint Rated and to download the Green Point Rated Checklist, go to Or contact
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