STRETCH CODE RESIDENTIAL REQUIREMENTS
PER 780 CMR 115.AA:
NEW RESIDENTIAL CONSTRUCTION (780 CMR, Section 401.2)
New low-rise (three stories or less) residential buildings including townhouses shall require a HERS (Home Energy Rating System) index rating as verified by a RESNET (Residential Energy Services Network) certified HERS rater.
1. For units equal to or greater than 3,000 SF, in conditioned floor space, a HERS rating of 65 or less is required.
2. For units less than 3,000 SF, a HERS rating of 70 or less is required.
3. In addition, all new construction shall demonstrate compliance with the Energy Star Qualified Homes Thermal Bypass Inspection Checklist.1
RESIDENTIAL ADDITIONS (780 CMR, Section 401.3 & .4)
Prescriptive Options: Additions to an existing building, building system or portion therof shall conform to IECC 2009, Chapter 4, and shall further demonstrate compliance with:
1. The Energy Star Qualified Homes Thermal Bypass Inspection Checklist.1
2. Fenestration U-factor requirements as listed in Energy Star program requirements for Residential Doors, Windows and Skylights – Version 5. 2
3. Ducts for new HVAC systems shall be sealed and test post-construction to demonstration leakage to outdoors of less than or equal to 4 cfm per 100 SF of conditioned floor area, except where the air handler and all ducts are located within conditioned space.
Performance Options: The performance approach and HERS ratings of 401.2 may be followed in lieu of the prescriptive requirements of this section.
RESIDENTIAL ALTERATIONS, RENOVATIONS OR REPAIRS (780 CMR, Section 401.5 & .6)
Prescriptive Options. Alterations, renovations or repairs that involve accessing the building envelope shall require the affected portion of the envelope to comply with 401.3. Envelope insulation shall meet or exceed IECC 2009 requirements (Chapter 4, Section 402) for climate zone 5, or fully fill existing cavities with insulating material which meets or exceeds an R value of R 3.5/inch.
Performance Option: In all cases of alterations, renovations or repairs the performance approach of 401.2 may be followed in lieu of the prescriptive requirements of Section 401.5 with the following HERS rating requirements:
1 For units equal to or greater than 2,000 SF in conditioned floor space, a HERS rating of 80 or less is required.
2 For units less than 2,000 SF, a HERS rating of 85 or less is required.
3 Compliance with the Energy Star Qualified Homes Thermal Bypass Inspection Checklist.1
The documents referenced above can be found at the following links or as attachments to this page.