Pitkin County takes aim on high-energy mansions
Real Estate Report: Aspen has long had a love-hate relationship with its big, fancy houses
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.
But 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.” But even newer and smaller houses, now capped at 14,000 square feet, use disproportionately more energy on a square-foot basis. 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. The county adopted a climate action plan in 2017, and in September 2019, adopted a resolution declaring a climate emergency sold – one of six such resolutions in Colorado and 50 nationally. The county’s new requirements governing energy use in residential buildings represent small, incremental efforts to back up those declarations.
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 2040 goal of reducing emissions 90 percent.
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. But 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 new regulations — the county’s two towns, Aspen and Snowmass Village, are not changing their regulations — 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. 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 produce as much energy onsite as it consumes.
Pitkin County’s new 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 nonprofit 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.
Updated building codes explain some of this gain. Between 2006 and 2012, updates of the International Energy Conservation Code elevated requirements 38 percent. 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. 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.
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 one-third of them between 5,000 and 14,000 square feet.
Starwood in Aspen, located in unincorporated Pitkin County, will be affected by the regulations. It has superb views of the ski area and a string of 14,000-foot peaks and 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 city of Aspen plans to target energy use in its commercial and multi-family building sector in a new program called Building IQ. Commercial and residential buildings in Aspen account for 58% percent of greenhouse gas emissions.
The benchmarking program will entail collecting information on the larger buildings. The city has 205 commercial buildings that account for just over 2.6 million square feet, while the 625 multi-family buildings account for more than 5.5 million square feet.
A proposed ordinance scheduled to be considered by elected officials this spring would require collection of energy use with the local utilities, Aspen Electric, Holy Cross energy and, for natural gas consumption, Black Hills Energy. The thinking, explains Laura Anderson from the city’s climate action department, is that you cannot manage what you don’t measure. Ultimately, the goal will be to take steps to ratchet down energy use through improvements in the buildings and their controls.
Aspen joins Denver, Boulder and Fort Collins among the 31 jurisdictions across the United States that employ energy benchmarking as a tool for driving down building energy use.
Denver’s benchmarking law requires owners and managers of all buildings of more than 25,000 square feet in the city to annually assess and report the energy performance of their buildings. The information is published on a website, which enables the market to better value energy efficiency.