Summit County set to adopt new sustainable building code to prepare for ‘net zero’ future

The Wintergreen housing development under construction in March 2018 near Keystone. New home construction in Summit County is set to require much higher standards for energy efficiency with the adoption of new building and sustainability codes.
Hugh Carey /

BRECKENRIDGE — Summit County is set to adopt a sustainable building code that would require new residential construction in the county to be among the most energy efficient in the nation. If adopted by the Summit Board of County Commissioners, Summit would be the first county in Colorado to adopt the Zero Energy Ready Home standards for new construction.

The standards were produced by the Department of Energy to get new homes ready for a “zero net energy” future, when home energy usage will not exceed the home’s own power generation through solar or other means of renewable energy production. The standard does not require new homes to be net zero but does require new home construction be much more efficient than current standards in preparation for the eventual jump to net zero.

High Country Conservation Center Climate Action Director Jess Hoover said the new code will supplement the already-adopted 2018 International Energy Conservation Code to help the county achieve its Climate Action Plan goal of zero carbon emissions by 2030. 

“Developing and updating the existing sustainable code was one of the strategies that came out of our Climate Action Plan that all of Summit County’s largest municipalities adopted last year,” Hoover said. “When we created the Climate Action Plan, our first step was to do greenhouse gas emission inventory, and we learned that two-thirds of greenhouse gas emissions in Summit County come from energy use in buildings.”

To reduce the carbon footprint that Summit’s homes produce, the county has ramped up the efficiency standards for new homes. The Zero Energy Ready Home standard uses the Home Energy Rating System to assess a home’s efficiency.

The rating requires a certified third-party auditor, called a HERS Rater, to assess a home’s efficiency on a scale from zero to 100. The lowest number is for a home that is net zero for energy efficiency, while 100 is based on the efficiency of a “reference” home as measured by the 2006 International Energy Conservation Code.

Homes rated higher than 100 are considered to be more inefficient than standard. To be Zero Energy Ready Home standard certified, a new home must have a rating in the 40s or 50s.

Summit County’s interim Chief Building Official Jeff Flynn said the various factors that goes into a rating are complicated and have to do with a home’s framing, insulation, windows, air filtration, plumbing, lighting, electricity and appliances. Overall, new homes are meant to be built more airtight, with little to no energy loss and highly efficient systems to keep energy use to a minimum.

Flynn said the county already had adopted standards “above and beyond” what is required for Zero Energy Ready Home requirements, but that the new sustainability code would require third-party verification.

Flynn said that while there hasn’t been any significant organized opposition to the new standards, there have been concerns about how much these new standards would add to home building costs. The Summit County Builders Association, representing the interests of area builders and developers, is not entirely convinced by rosy outlooks of long-term energy savings making up for increased costs, which High Country Conservation Center downplays as adding only 1% to 2% to overall costs.

“We’ve heard different things from different people, so I think that’s a point of debate,” Summit County Builders Association Executive Officer Marilyn Hogan said. “Some people are seeing 1% to 2%, but it seems significantly more to some builders who have looked at it.”

Another sustainable code requirement is requiring new homes to be electrical vehicle ready, having the required build out and electrical planning to accommodate charging stations. 

At the board’s work session Tuesday, Feb. 4, the commissioners floated the possibility of adopting a code similar to the one in Boulder, which requires future multifamily condo developments to have 50% of parking spaces accommodate electrical vehicles. That would be much less aggressive than Denver’s new standard of requiring 80% of parking spaces in multifamily units be for electric vehicles.

If the board adopts the new code, it would be implemented along with the new building code July 1, with a six-month grace period. The commissioners will pick the topic back up for discussion in March.

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