Massachusetts "Stretch Code" Appendix 120AA (Voluntary)


In July 2009, Massachusetts became the first state to adopt an above-code appendix to its state code - the 120 AA ‘Stretch’ Energy Code. The ‘Stretch’ Code is an enhanced version of the 2009 IECC with greater emphasis on performance testing and prescriptive requirements. It was designed to be approximately 20 percent more efficient than the base energy code - the IECC 2009 for new construction, with less stringent requirements for residential renovations.

It divides commercial buildings by size and type. Buildings less than 5,000 sq. ft., “specialty buildings” less than 40,000 sq. ft. (supermarkets, warehouses, and laboratories), and renovations are exempt. Buildings larger than 100,000 sq. ft. and “specialty buildings” larger than 40,000 sq. ft. must exhibit a 20 percent reduction in energy use from ASHRAE 90.1-2007 using approved energy modeling. Buildings between 5,000 and 100,000 sq. ft. can meet the same performance requirements or a prescriptive code based on a codified version of New Buildings Institute’s (NBI) Core Performance Guide, which includes more stringent building envelope and HVAC equipment requirements than the 2009 IECC and new requirements for commissioning, air barriers, and lighting controls.

New residential construction will require a Home Energy Rating System (HERS) score of 65 or less for homes 3,000 sq. ft. and larger and 70 or less for those smaller than 3,000 sq. ft., as well as compliance with the ENERGY STAR Qualified Homes Thermal Bypass Inspection Checklist. Additions must meet the same performance requirements, whereas renovations will require a less stringent HERS rating (80 or 85 for homes 2,000 sq. ft. and larger or smaller, respectively). Both can also comply with ENERGY STAR for Homes prescriptive requirements, plus meet or exceed 2009 IECC insulation requirements.

Fifty-nine Massachusetts cities and towns have adopted the stretch energy code as of November 18, 2010. An updated map is available here. A town or city which adopts the appendix must also provide energy code training to the building officials in its area. This requirement is supported by stimulus funded training on energy codes offered around the state on both residential and commercial IECC 2009 and stretch energy codes. Under state law, the more stringent standards will be mandatory statewide by the end of 2012, eliminating any differences between communities.

A concurrency period and a training policy were approved at the Massachusetts Board of Building Regulations and Standards (BBRS) meeting on May 12. A concurrency period exists when either the new code or the existing code can be used, but not combined. The BBRS approved a concurrency period of six months, with such period to begin on either January 1 or July 1 of any year.

Massachusetts was selected as one of BCAP's 'Ten Places to Watch' for the state's efforts to distinguish itself in the energy codes world.  As the year advances, BCAP will track their progress, highlight their successes, encourage dialogue with interested outside organizations, and share their best practices and lessons learned with other places throughout the country looking to improve their energy code policies.

Back to Massachusetts Code Status

Date Passed: 
Wednesday, July 1, 2009
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