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Colorado’s Pitkin County wants to begin taking steps to net-zero energy homes by 2030

  by Allen Best

Aspen has long had a love-hate relationship with its big, fancy houses. On one hand, the houses there and in surrounding unincorporated Pitkin County keep real estate agents, builders, and remodelers gainfully employed.

Energy use by these big houses rankles local sensibilities. Some of it has to do with the sheer size: The largest—a 56,000-square-foot edifice built for a Saudi prince—redefines the word “mansion.” Even newer and smaller houses, now capped at 14,000 square feet, use disproportionately more energy on a square-foot basis than smaller houses. Then there are the heated driveways, outdoor swimming pools, and patio hot tubs.

The first response of Aspen and Pitkin County in the late 1990s was the Renewable Energy Mitigation Program (REMP), which applied to both houses of more than 5,000 square feet and their outdoor spaces. Builders and homeowners had a choice. They could install on-site renewable energy to compensate for the energy extravagances, or they could pay into a fund used for energy efficiency or renewable energy elsewhere in the Roaring Fork Valley.

REMP was provoked by concerns about the pollution caused by burning coal, but growing climate change worries have now driven Pitkin County to embrace more aggressive efforts to reduce greenhouse gas emissions caused by buildings.

Now comes climate change

The county adopted a climate action plan in 2017. In September 2019 it adopted a resolution declaring a climate emergency. It was at that time one of six such resolutions in Colorado and 50 nationally.

The requirements governing energy use in residential buildings now being considered by Pitkin County represent small, incremental efforts to back up those declarations.

The first hearing by the Pitkin County commissioners is expected in late May, followed by a second hearing a month later.

This is from the May 11, 2020, issue of Big Pivots. For a sample copy, send you e-mail address to [email protected]

Buildings, both residential and commercial, are becoming a focal point of efforts as Colorado sets out to decarbonize its economy as directed by a 2019 state law. The law sets a 2050 goal of reducing emissions 90%.

A Colorado Department of Public Health and Environment report projects that transportation will become the leading source of carbon dioxide emissions in Colorado during 2020, followed closely by production of electrical power.

Whereas coal plants are being closed and electrified cars, buses and other vehicles are making inroads, buildings normally remain little changed for decades, even centuries. Getting them right the first time matters.

Pitkin County’s proposed regulations—the county’s two principal towns, Aspen and Snowmass Village, are not changing their regulations—would apply to all new and remodeled houses, regardless of size, as well as additions.

Regulations concerning exterior energy uses for heated swimming pools and the like will remain unchanged. The new program employs the Home Energy Rating System, or HERS, the homebuilding industry’s standard for measuring energy efficiency.

How HERS works

HERS ratings provide a tool for comparing the energy efficiency of houses: The lower the number, the greater the efficiency of energy use. A house built to satisfy the energy efficiency requirements contained in the 2006 national building codes will achieve a score of 100. Older, drafty and uninsulated houses might score 150 or even 200. To achieve a house with a HERS rating of zero would require that it produces as much energy onsite as it consumes.

Pitkin County’s program, called HERS30/NET 30, will require that HERS scores of 60 be the starting point. The county looks to get more ambitious yet, requiring net-zero by 2030.

Why not now? Brian Pawl, the chief building official for Pitkin County, told county commissioners in November that building materials and markets by then will have caught up with net-zero goals.

Mona Newton, who directs the Aspen-based Community Office of Resource Efficiency, a non-profit created to drive energy efficiency in buildings, says HERS is a valuable tool. “Everybody is struggling to achieve net-zero (emissions) buildings,” she says. “Even if you can’t meet that goal, HERS can tell you the opportunities for getting there.”

In Colorado, production builders along the Front Range have mostly been getting HERS scoring of 60 or a little better, reports Ryan Meres, a program director for RESNET, a national standards-making body for building energy efficiency and certification systems. In other words, they deliver 40% more energy efficient homes than the 2006 code required.

Role of  building codes

Updated building codes explain some of this gain. Between 2006 and 2012, updates of the International Energy Conservation Code elevated requirements 38%. A new state law requires that jurisdictions that have adopted the codes update them to the most recent three iterations, currently 2018, 2015, or 2012. California’s more stringent requirements governing building energy have a secondary effect in Colorado, as most production builders operate in both states.

In Colorado, both Boulder and Boulder County already have HERS-based building requirements for new and remodeled homes. In one key respect, they’re stronger, not awaiting new materials and markets. Any new or rebuilt house of more than 5,000 square feet must achieve a HERS rating of net-zero in those two jurisdictions. Further, the houses must have designs and materials necessary to achieve a HERS rating of 40 or less. As house sizes decrease, the requirements recede. A house of 1,500 square feet or less need only hit a HERS score of 60.

“As the houses get bigger, they do consume disproportionately more energy, so that’s why we scale it up,” says Ron Flax, the chief building official for Boulder County. The county plans to increase requirements to require all new houses to achieve HERS scores of net-zero beginning in 2022.

The city and county tend to work in tandem, but the same regulations do not apply to Lafayette, Louisville, and other municipalities within the county.

Cost and comfort emphasized instead of climate as natural gas lines stubbed

But in one crucial way, Pitkin County’s new regulations will leapfrog past those of Boulder and Boulder County. Each new house must have 36 square feet dedicated for potential batteries. This matters in a place where real estate gets measured in square inches, not square feet, says Pawl, the building official. The precise requirement for battery storage is 25% of installed kilowatts of photovoltaic production.

This requirement was triggered in part by the Lake Christine wildfire in 2018. Started by target shooters near Basalt, the fire soon engulfed the Roaring Fork Valley in smoke and nearly caused Aspen to be without electricity during the busy July Fourth weekend.

In 2019, the county issued permits for 25 houses. More than a third of the new houses were for between 5,000 and 14,000 square feet.

Starwood in Aspen

Starwood in Aspen will be affected by the regulations. It may be the only subdivision to be a title for a popular song, John Denver’s 1971 “Starwood in Aspen.” Contrary to its name, though, it’s actually outside the city limits and in unincorporated Pitkin County. It has superb views of the ski area and a string of 14,000-foot peaks. Its prices are just as lofty, most houses worth $5 million to $10 million, but some much more. Meg Haynes, executive director of the homeowners’ association, says Starwood is very interested in working with Pitkin County to be a model in energy use. This interest, she confirms, reflects an evolved embrace of the challenge of energy.

The changes underway in Pitkin County echo another time of great transformation. Rich silver ores quickly transformed the mining camp called Ute City in 1879 into a city of wondrous buildings. By 1885, the rushing creeks had been harnessed to electrify street lights, said to be the first in the American West.

As with its founding, the Aspen area wants to be at the front of change, creating a resilient and zero-emissions grid.

See also: Tightening the Roaring Fork Valley’s energy belt

Aspen’s Building IQ benchmarking program

This story originally was published in somewhat revised fashion in the January 2020 issue of Colroado Biz magazine.


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