- Overview of the Massachusetts Stretch Code
- February 3, 2011 | Author: Jennifer Sacco Smith
- Law Firm: Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. - Boston Office
In May 2009, Massachusetts became the first state to adopt a “reach” or “stretch” code above the Commonwealth’s base building energy code, which consists of the International Energy Conservation Code (IECC) 2009, further described below, and Massachusetts-specific amendments.1 In response to municipal demands for additional stringency in the building energy code, the Massachusetts Board of Building Regulations and Standards adopted an optional appendix to the Massachusetts Building Code, 780 CMR. The appendix, Appendix 120.AA, is known as the “Stretch Energy Code” or more simply, the “Stretch Code.” While it is optional for municipalities to adopt the Stretch Code, as of November 19, 2010, 64 municipalities in Massachusetts have adopted the new Stretch Code, including the City of Boston and the City of Cambridge. Once municipalities have opted in and adopted the Stretch Code, compliance with its terms is mandatory.
The purpose of the Stretch Code is to increase energy efficiency in buildings across Massachusetts. The Stretch Code regulates the design and construction of buildings for the effective use of energy and is intended to provide flexibility to permit the use of innovative approaches and techniques to achieve the effective use of energy. The Stretch Code requirements result in 20% greater building efficiencies over the Massachusetts base building energy code. As previously indicated, the Commonwealth’s base building energy code is currently the International Energy Conservation Code (IECC) 2009 with Massachusetts-specific amendments. Pursuant to the Green Communities Act of 2008, Massachusetts is required to adopt each new IECC (updated every three years) within one year of its release; the next version will be IECC 2012. During that year of transition, an updated stretch code will be considered and the current Stretch Code is expected to be incorporated into the 2012 state building energy code update, thus making the current Stretch Code mandatory for all municipalities at that time. By putting an optional Stretch Code into place now, expectations are set for the 2012 state building energy code update and municipalities are provided an opportunity for early adoption of the future 2012 state building energy code.
The Stretch Code applies performance measurements to both new construction and renovations of residential buildings and new construction of commercial buildings, but does not require modifications of existing buildings. New construction requirements in municipalities that adopt the Stretch Code are as follows:
Under the Stretch Code, the performance measurement used for residential construction is the Home Energy Rating System (HERS).2 New low-rise (three stories or less) residential buildings including townhouses are required to (1) obtain a HERS rating of 65 or less for units equal to or greater than 3,000 s.f. of conditioned floor space; (2) obtain a HERS rating of 70 or less for units less than 3,000 s.f.; and (3) demonstrate compliance with the Energy Star Qualified Homes Thermal Bypass Inspection Checklist (visual inspection of framing areas where air barriers are commonly missed and inspection of insulation to ensure proper alignment with air barriers).3 A HERS index of 65 means that the residence is estimated to use 65% as much energy as the same home built to the 2006 IECC for a 35% annual energy savings.
For additions and renovations to existing residences, either the HERS performance measurement may be used or a prescriptive approach may be used. Under the HERS option, the following is required: (1) obtain a HERS rating of 80 or less for units equal to or greater than 2,000 s.f. of conditioned floor space; (2) obtain a HERS rating of 85 or less for units less than 2,000 s.f.; and (3) demonstrate compliance with the Energy Star Qualified Homes Thermal Bypass Inspection Checklist. Under the prescriptive option, the affected portion of the residential building envelope shall (1) demonstrate compliance with the Energy Star Qualified Homes Thermal Bypass Inspection Checklist and (2) meet or exceed IECC 2009 requirements for climate zone 5 or fully fill existing cavities with insulating material which meets or exceeds an R value of R 3.5/inch.
For new construction of commercial buildings, the Stretch Code uses ASHRAE 90.1-2007 Appendix G (an industry-accepted energy modeling methodology) as the performance measurement and also offers an option of a prescriptive code for small and medium-sized commercial buildings. Large buildings over 100,000 s.f., special energy use buildings (supermarkets, warehouses, and laboratories) greater than 40,000 s.f. in area, and additions to such buildings greater than or equal to 30% of the existing conditioned floor area must be designed to achieve energy use per square foot equal to at least 20% below the energy requirements of ASHRAE 90.1-2007 Appendix G.
Small and medium-sized commercial buildings between 5,000 and 100,000 s.f. and additions to such buildings greater than or equal to 30% of the existing conditioned floor area where the addition has its own heating system may meet the same 20% better than ASHRAE 90.1-2007 Appendix G performance standard or use a simplified prescriptive method. The prescriptive method requires compliance with certain building envelope requirements, building mechanical system requirements, service water heating requirements, electrical power and lighting system requirements, and one of three compliance options: efficient mechanical equipment, reduced lighting power density, or on-site supply of renewable energy. Commercial buildings smaller than 5,000 s.f., building renovations, and special energy use buildings (supermarkets, warehouses, and laboratories) below 40,000 s.f. in area are exempt from the Stretch Code.
In deciding to adopt the Stretch Code, municipalities must weigh the expected benefits against the anticipated costs. Anticipated costs include higher initial construction costs; however, after energy cost savings on heating and electricity are taken into account, the higher performance standards lead to savings. Noted benefits include meaningful action on energy consumption, cost savings for residents and businesses, increase in design and construction firm competitiveness, and eligibility for Energy Star rebates and utility energy efficiency rebates. One Stretch Code municipality noted that benefits included consumer protection in the form of a marketable performance measure to provide a basis upon which to compare the energy use and cost of operating a building as well as savings over the life of the building. While each municipality will need to evaluate these costs and benefits, property owners and building professionals will need to fully prepare for possible changes and obtain the knowledge to carry out the new Stretch Code requirements.
1 The current base building code for Massachusetts is the 8th edition of the base code at 780 CMR (the “MA State Building Code”) which consists of the International Building Code (IBC) 2009 with Massachusetts-specific amendments. The energy conservation provisions of the MA State Building Code incorporate the International Energy Conservation Code (IECC) 2009 with Massachusetts-specific amendments and such energy conservation provisions are included in Chapter 13 Energy Efficiency (Commercial Energy Code) and Appendix J (Residential Energy Code). See http://www.mass.gov/?pageID=eopsterminal&L=4&L0=Home&L1=
2 The HERS Index is a scoring system established by the Residential Energy Services Network (RESNET) in which a home built to the specifications of the HERS Reference Home (based on the 2006 IECC) scores a HERS Index of 100, while a net zero energy home scores a HERS Index of 0. The lower a home’s HERS Index, the more energy efficient it is in comparison to the HERS Reference Home.