Stretch code
anderslewendal
| Posted in Energy Efficiency and Durability on
Martin: If you wanted your town to encourage a “stretch code” or encourage builders to surpass the state IECC, what five things would you ask for? Remember that cities likely cannot afford to incentivize Passive Homes. The options should produce long term efficiency and be affordable. I am asking all of my energy efficiency gurus for ideas.
Anders Lewendal, Bozeman, Montana
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Replies
Anders,
I can answer questions about heat flow and moisture accumulation, but not about the U.S. political process.
If there are any political consultants who happen to read GBA, perhaps one of them can offer some advice.
You could take the California Title 24 approach, and require Manual-Js for specifying the HVAC equipment, as well as duct leakage testing (with specified limits.) Oversized air handlers/furnaces can mask the deficiencies of leaky ducts- it's common to find 25% or more of the air going somewhere unintended.
The Energy Star duct leakage limits and 3 pascals max room-to-room pressure limit when air handlers are operating (doors closed or open) aren't ultra stringent, but sure beats "typical" performance of leaky untested unbalanced duct systems. There may or may not be sufficient contractors to provide those services though.
Similarly, requiring blower test reports verifying it meets the IECC's 3ACH/50 limit prior to sale/occupancy might fly, provided there are sufficient contractors who can provide that service.
You'll need large bags of money because vested interests will point to the high cost of housing in markets such a Colorado and Calif as examples of the assault upon the "American Dream" of home ownership for middle class Americans. People generally aren't receptive to someone who lives in a 6k sqft house to telling them that they should be happy with an energy efficient 1k sqft house.
Montana, like most States, is now requiring older codes. You really don't need "stretched codes", you need the State of Montana to update to the 2015 or 2018 code, and truly enforce it.
Unfortunately, most municipalities around the country are underfunded and uneducated in new building practices and building sciences, so many building departments are passing the buck to Raters and Verifiers, many of whom are not sufficiently educated or experienced.
If any Builder in Montana, or anywhere else, wants to build a great house, all he/she needs to do is follow the new code to the "T", just as a matter of pride and doing an honest job. Its all about paying attention to details. No Builder needs to have any "verifier" looking over their shoulder just to do the job he/she is hired to do.
All our projects are Zero Energy Ready homes and we take additional steps above code and make it a written goal of our Plans & Specifications to have 1ACH50, HERS45, all HVAC systems inside the conditioned space and properly designed, installed and commissioned with good fresh air make-up and ventilation. In addition, no indoor open flame fireplaces, no gas stoves, improved wall and roof assemblies, insulated foundations and flatwork, etc.
Here at the GBA you can find "Best Practices" for anything you want in Green Basics, Detail Library, Green Homes and Q&A, to build any house well and above code. You just have to make the time and do the research.
You can also go the following program's websites for FREE INFORMATION: DOE's Zero Energy Ready Home Program, Building America Solution Center, EPA Indoor airPLUS, NAHB Green, USGBC-LEED and Building Science Corporation, just to name a few.
>"You really don't need "stretched codes", you need the State of Montana to update to the 2015 or 2018 code, and truly enforce it."
Hear hear!
The number of states & towns that actually require blower door testing to demonstrate compliance with the IRC limits as a condition of getting an occupancy permit are few.
Occupancy Permit! My town doesn't even require a building permit.
That's fine Stephen, but do you live in Bozeman MT?
Does Bozeman require inspection sign-offs for occupancy on new construction? (apparently yes: https://www.bozeman.net/Home/ShowDocument?id=74 )
A code that has no enforcement teeth may be a nice guideline but doesn't necessarily change how things are actually done.
It looks to me like model code has been stretched to the point insulating much beyond it will not make economic since. Now actually enacting and enforcing the most current model code would be a great goal because it so rarely happens.
Walta
You may want to take a look at the British Columbia Step Code.
Thank you everyone for the input. Yes, Bozeman does enforce Montana's adopted code and yes, we are still on the 2012 IECC. However, we do require a certified blower door test to 4ACH @50 to get a certificate of occupancy. The city cannot force builders to go beyond the code, however, they are hoping to incentivize some improvements. Designing south facing pitches on new homes that can accommodate a minimum 5KW PV system is one option. A 2ACH certificate could be another option. I like the idea of the manual J option.
I agree that funding incentives will likely kill the idea of going beyond the code. We'll see if Montana adopts the 2018 IECC in the next cycle.
Thanks.