What other communities are doing California: Non-mandatory initiative that all new residential construction will be net zero by 2020 Montpelier, Vt.: Stated goal of making most homes “net zero ready” by 2030 Cambridge, Mass.: Goal of new homes achieving zero net emissions by 2022, pending economic analysis and public review Lancaster, Calif.: Requires that new homes have a minimum of 1 kWh of solar PV collectors

If You Go What: Boulder County Board of Review meeting When: 4:15 p.m. Tuesday, Oct. 13 Where: Boulder County Courthouse 3rd floor hearing room, 1325 Pearl St. Info: Public input and feedback will not be taken at this public meeting

Boulder County may be the only government in the U.S. with a legal requirement that all new homes must produce as much energy as they consume by 2022, according to interviews with a dozen national and regional energy experts.

“Nationally, there are communities and states with net zero goals,” said Jim Meyers, with the Southwest Energy Efficiency Project, including Colorado municipalities with sustainability initiatives. “But the plans do not specify to the level of detail that Boulder County has specified.”

The mandate, established in 2013, is part of the county’s ambitious sustainability plan, which also includes reducing vehicle traffic and other activities that produce harmful greenhouse gases in an effort to dramatically reduce carbon emissions and slow global warming.

On Oct. 13, the county Board of Review, a panel of building professionals who review and modify codes, will decide whether to recommend continuing the next phase of the net zero program to the county commissioners, bringing homes of 5,000 square feet or greater into the fold by Jan. 1, 2016.

The program is being phased in over ten years, with large homes targeted first, then smaller homes facing the same requirement over time. Initially, only homes 8,000 square feet or larger were held to the standard. Currently, it applies to houses 6,000 square feet or greater.

Cost concerns slow program goals

The original plan had been to apply the standard in 2016 to smaller homes at 4,000 square feet, the average size of a home in unincorporated Boulder County, the only area affected by the requirement. But concerns over cost in the already-expensive market caused staff to pull back slightly.

“The decision was made early on that this might have been too fast, too early,” said Ron Flax, sustainability examiner for the county.

How to measure the costs of net zero construction is a contentious issue, with advocates saying the practice can be done in an affordable way, and builders and others saying there’s no question but it adds significant cost.

Local architects and builders say a 15 percent increase is the generally accepted cost associated with net zero builds, but those in the sustainable space argue that efficient homes can be built for much less if designed well.

For now, there has been no effort by the county to analyze the costs, in part because of the lack of data available.

“We don’t have access to good data,” Flax said, because parties applying for building permits self-report the proposed cost of the project — and those figures often leave out “soft costs” such as architectural and engineering fees that can be higher when working with professionals experienced in sustainable building.

“We are looking at numbers that aren’t quite as accurate as we would hope.”

What’s being done around the nation

A 2012 report in California reported that “recent studies have indicated that the efficiency components of a new zero net energy home have an incremental cost” after incentives, a multitude of which are available for homeowners for everything from efficient appliances to solar panels.

California has set a statewide goal of all new home construction being net zero by 2020 — but there is no legal mandate to do so.

Similarly, the city of Cambridge, Mass., set a goal of new residential homes achieving zero net emissions by 2022. It was approved by the city council earlier this summer.

But Cambridge differs from Boulder County because its goal isn’t backed by a legal requirement that new homes produce as much energy as they consume.

The city plans to submit a proposal for a legal mandate in 2020, following an economic analysis and reception of public feedback.

“You have to make changes in the context of what makes sense economically,” said Susanne Rasmussen, director of environmental planning for Cambridge. “That’s why we didn’t want our plan to lock in when those (goals) will become regulations.”

Several other communities around the state and country have set goals for energy efficiency and reduced emissions without mandating that net zero requirements be met.

Montpelier, Vt., has a stated goal of making most homes “net zero ready” by 2030, meaning they can accommodate a renewable energy source at some point in the future. In Lancaster, Calif., any single-family homes built in 2014 or after are required to be equipped with at least 1 kilowatt-hour of solar photovoltaic (PV) panels.

‘What the future is going to be’

Closer to home, both Aspen and Fort Collins have set carbon reduction targets, and Aspen, which operates a municipal utility, this year achieved its goal of producing all its energy from renewable sources —the third U.S. city to do so, after Burlington, Vt., and Greensburg, Kan.

Sustainablility leaders for both municipalities said the discussion on net zero is ahead.

“Specifically in building construction, net zero so far hasn’t picked up a lot of speed in Fort Collins,” said John Phelan, energy services manager. “I’m sure it’s going to be part of our tactical discussion, because it has to be, but we’re not quite there yet.”

With an aggressive goal of 80 percent reduction in carbon emission by 2030, Phelan said residential impacts will have to be considered at some point.

“We won’t get there if we don’t radically address our building goals.”

Nationally, residential and commercial energy use accounts for about 12 percent of greenhouse gas emissions. But in smaller study areas, the high percentage of homes and relative lack of industry means that residential energy use is a bigger piece of the emissions pie.

In unincorporated Boulder County, for instance, residential energy use accounts for 28 percent of the area’s total emissions.

As the role of homes in energy consumption and emissions becomes better understood, more municipalities will look to building standards as a way to achieve climate goals, said Boulder County’s Flax. That is evidenced by the adoption of energy efficient standards into the national and international building codes in 2012 and 2015.

“That really has been the biggest tool in our tool box for increasing energy efficiency,” he said. “This is what the future is going to be, and we’re at the forefront.

“What was at one point really cutting edge is becoming the standard.”

Shay Castle: 303-473-1626, castles@dailycamera.com, @shayshinecastle