As of January 1, 2011, 58 Massachusetts communities have adopted the “Stretch Energy Code in which weatherization, insulation, heating, cooling, and mechanical air exchange requirements are more stringent than the state’s already strict laws. The stretch code appendix offers a streamlined and cost effective route to achieving approximately 20% to 35% better energy efficiency in new residential buildings, and 20% in new commercial buildings, than is required by the existing base energy code.

Why?  Implementation of the stretch energy code in new construction can add $10,000 or more, as well as a imposing a huge new hurdle for homeowners, contractors and handymen in the towns that adopt it. Contractors are already reeling from the very severe requirements and penalties related to the new EPA lead paint law.  On the other hand, the state has sweetened the pot for town officials, because dopting the stretch code would make towns eligible for grants as a Massachusetts Green Community.  However, these grants are funded by Federal energy grants to the states which have not been renewed for 2011.  The Stretch law has been defeated in several town meetings.

Towns in Massachusetts that have adopted the Stretch Energy Code as of 2011.
Towns in Massachusetts that have adopted the Stretch Energy Code as of 2011.

Adoption: Towns and cities in the Commonwealth may adopt Appendix 120.AA as an alternative to the base energy efficiency requirements of 780 CMR and the forthcoming 8th edition, which will be based on the recently published IECC (International Energy Conservation Code) 2009 energy code. The stretch code may be adopted by any municipality in the commonwealth, by decision of its governing body.

For residential construction a performance-based code requiring a Home Energy Rating System1(HERS) index score  of 65 or less for new homes above 3,000 square feet and 70 or less for new homes below 3,000 square feet, HERS index of 80 or less for major renovations to homes above 2,000 square feet, or 85 or less for homes below 2,000 square feet. All renovations and additions may instead use a “prescriptive” approach, where specific efficiency measures are required rather than a HERS index number. The HERS rating is roughly the inverse of the energy saved under these standards as compared with the state’s standard code, ie 35% energy saved = 65 HERS index.

Renovations: The ‘stretch’ energy code has less stringent energy performance requirements for renovations than for new buildings, and  renovators may install  specified efficiency measures and opt out of performance testing. For existing homes being renovated or expanded you may use a HERS rating or the voluntary Energy Star Builders Option Package  and the base IECC 2009 code for  wall insulation. Only new commercial buildings are covered by the stretch code requirements. Only the systems being modified have to be brought up to code. Additions to existing buildings are treated in the same way as new construction. The stretch code allows an exemption for listed historic buildings. There are no standards for renovating commercial buildings

Testing:  Residential buildings meeting the stretch code through a HERS rating and thermal bypass checklist require independent certification by a HERS rater.  Submission of a copy of the HERS report, a completed Energy Star Thermal Bypass checklist, and posting the relevant energy data on the electrical panel in the home are required and must be submitted to the local building inspector prior to receiving a certificate of occupancy.

Wall insulation:  R-19 wall cavity insulation is now required in an update in the Massachusetts 7th Edition Building Code.

Resources:
Massachusetts New Homes with Energy Star program
RESNET
ICC
Core energy code
The ASHRAE 90.1-2007 standard
Q&A for MA Stretch Energy Code

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