Aspen’s building code headed toward net zero

Aspen City Council is on the fast track to adopting a new building code that focuses on not only energy efficiency but also net-zero waste in demolition of old buildings and onsite renewable sources for new structures, among other measures.

The city’s building code gets updated every six years and is due for one this year or in early 2022.

While the code was forward-thinking in 2015, the updated one will be crafted to be in line with the city climate action plan, council members agreed Monday during a work session.

Buildings are responsible for 58% of greenhouse gas emissions in Aspen, according to city officials.

Between 2004 and 2017, natural gas emissions in Aspen were reduced by 3%, despite significant growth in construction.

That’s attributed to the power of the code to reduce energy use.

Considering the Climate Action Plan goal to reduce community emissions by 80% by 2050, the city’s building codes are ripe for opportunity toward that effort, council members said.

Rather than wait for other jurisdictions to coordinate their building and energy codes, which would put adoption in the middle of next year as suggested by staff, the majority of council wants to expedite the work.

“A regional collaboration is super important, and I want to make sure we are engaged, but the climate is not waiting for their calendars and I don’t think we should, either,” Councilman Skippy Mesirow said. “Let’s do both, but let’s act quickly and we do have a shot clock.”

Nick Thompson, a plans examiner in the city’s building department, said there is some benefit to having consistent code adoption throughout the region.

It will have a greater impact on the regional climate-change efforts to have the most current energy efficiency codes in play in as many jurisdictions as possible, he noted.

“Giving ourselves time to do this right — because some of this stuff is a heavy lift — could be a little controversial, and we want to look toward what other communities are doing,” Thompson said, also acknowledging that jumping ahead would mean fewer buildings built to a lower standard.

Council agreed that further energy savings and greenhouse-gas reduction can come in the areas of net-zero construction, electrification and embodied energy.

Thompson and Bonnie Muhigirwa, also a plans examiner with the city, explained that as officials look to the future, there will likely be a need to improve energy efficiency in buildings but there will begin to be diminishing returns for the effort.

So instead of reducing energy use to zero, the remaining energy is offset with onsite renewable sources such as solar photovoltaic, according to city officials.

To avoid allowing inefficient buildings to just build a larger solar array to get to net zero, a minimum threshold of building efficiency could be established.

Councilman Ward Hauenstein said one way to reduce carbon is to put a cap on how much a structure can produce and limit square footage, which eliminates the inequities of rich people being able to offset their energy consumption by paying for it.

“Perhaps a building is allowed to be larger if it produces less carbon, and I think Boulder has a requirement that if a house were 5,000 square feet it has to be net zero, so something like that gains traction with me,” he said.

Mesirow also said he supported downzoning residential homes and upzoning multi-family buildings.

“More large, empty homes are not good for our lived-in community goal, but they’re really terrible for our environmental goals because those giant structures get heated all the time,” he said.

Council members also were in agreement that electrification can address the conundrum of a net-zero building creating greenhouse-gas emissions if there is fossil fuel combustion on site.

Electrification is transitioning appliances and equipment that would otherwise run on natural gas, like boilers, water heaters, stoves and clothes dryers, to clean and efficient electric versions using electricity sourced from a carbon free grid.

The city’s electric utility grid is currently carbon-free, and the other electric provider, Holy Cross, has committed to being carbon-free by 2030, according to city officials.

The full life cycle of a building indicates that there are significant emissions generated from the harvesting, manufacturing and transporting of building materials, and then from the release of carbon at the end of a structure’s life when it goes into the landfill.

Council members said they want the city to up its game in curtailing construction and demolition waste, recognizing that it contributes to emissions and is shortening the life of the landfill.

“The net-zero waste to me is a really high priority,” Councilwoman Ann Mullins said. “Once that landfill is gone, people keep forgetting the impact that it is going to have on the city and the county.”

Council also agreed to add up to 45 electric vehicle charging stations around town in the next five years, as well as to begin next year charging a fee to users to cover the costs of electricity use.

The city currently has eight public charging stations, and staff is anticipating increased demand as more people buy electric vehicles.

csackariason@aspentimes.com