Friday, October 2, 2009
Selectmen consider “stretch code” for new building projects
To promote improved energy-efficiency for new and renovated buildings, Carlisle Energy Task Force member Glenn Reed and Building Inspector John Luther asked the Selectmen on September 22 to consider adoption of the “stretch code” to the current building code.
Luther said that it is a performance-based code requiring that a Home Energy Rating System (HERS) index score be certified by a third party rater and submitted to the Building Inspector. Lower scores mean better efficiency. When asked about the impact on cost, Luther said that it would be about $8,000 to $9,000 for a typical 2,700 square foot house but with first-year energy savings estimated at $800 to $900.
As stated in the web site http://bcap-energy.org/note/418, the stretch code is an optional amendment to the seventh edition Massachusetts Building Code 780 CMR, and was developed in response to the call for improved local building energy efficiency in the state. Towns and cities may adopt Appendix 120AA as an alternative to the base energy efficiency requirements of 780 CMR. The appendix, intended to improve energy efficiency of both residential and commercial buildings, is designed to be about 30% more stringent than the 2006 IECC/ASHRAE 90.1-2004.
Board of Selectmen Chair Tim Hult said that they should schedule a public hearing and that builders working in the community should be invited. He said, “I don’t pretend to know how they would respond.”
Selectman Peter Scavongelli said, “Depending on timing, Benfield (Benfield Farms 40B development) could be subject to this.”
Easier requirements for renovations
The stretch code specifies a HERS index of 60 or less for new homes, both single-family and multi-family; HERS index of 70 or less for major renovations; or 85 or less where existing heating systems are retained. A HERS index of 60 means that the home is estimated to use 60% as much energy as the same size and type of home built according to the standards of the 2006 Massachusetts energy code, which would have a HERS index of 100. ∆
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