|Action||Update the Uniform Statewide Building Code|
|Comment Period||Ends 5/26/2017|
Thank you for the opportunity to submit comments.
My comments pertain to the State Building code 13VAC5-63. The Commonwealth should adopt all of the 2012 and 2015 energy conserving provisions recommended by the International Energy Conservation Code (IECC) which the state promised to do when it accepted its stimulus grant funds when Kaine was governor.
If that is not possible, I urge you to address the following issues:
1) Building envelope tightness—The envelope is the air barrier. The IECC’s current standard is 3 air changes per hour using a mechanical blower door to verify compliance. The current Virginia code (VAUSBC) “requires” an independent blower door test with no more than 5 air changes per hour with the option of permitting a visual inspection in lieu of the the blower door test. Please institute a code amendment to delete the visual inspection option from the code and to lower from the current 6 to 3 the permissible number of air changes per hour as recommended by the IECC.
2) Duct tightness—Ducting in new construction usually penetrates the building envelope to enter into attic space or crawl space. If the ducting is leaky, the conditioned air is vented out (into the attic or crawl space) and the energy used to condition (heat/cool/ dehumidify) it is of course entirely wasted. The IECC’s current standard is 4 CFM using a mechanical duct blaster test to verify compliance. Ideally the ducting would have zero leakage. Currently the VAUSBC limits leakage to 8 CFM determined by a duct blaster test with the option for a visual inspection. Please implement code amendments to delete the visual inspection option and lower the leakage rate to 4. A higher rate may be suggested if the entire system, air handler and all ducting are within the building envelope, i.e. not in the attic.
3) Increase wall R value from 15 to 20. In conventional stick built construction this typically means installing an insulated exterior sheathing or using 2 X 6 exterior studs.
4) Increase attic R value from 38 to 49. Here we are also looking for use of elevated hip roofing at the top of the exterior walls to permit sufficient space for insulating at R49.