Mt. CB addressing residential building energy use

Potential programs to mitigate exterior and interior energy efficiency 

By Kendra Walker

The Mt. Crested Butte town council is looking at more measures to work toward additional sustainability and climate action planning. During a work session on December 17, the council discussed opportunities to enhance energy conservation for new construction and remodels in the town. 

This past fall, the council adopted the 2021 Building Codes and the Colorado Model Energy Code, which aim to improve energy efficiency compared to the 2015 Building Codes by incorporating advanced building envelope standards, enhanced insulation requirements and stricter energy performance metrics to reduce carbon emissions and promote sustainable construction practices. These 2021 Building I-Codes go into effect January 3. 

The council is now looking for opportunities to enhance energy conservation beyond the 2021 I-Codes and potentially require above-code standards for new buildings. “This can be achieved by targeting building energy use in new residential construction through programs focused on either exterior and/or interior energy efficiency,” explained planner II Shannon Hessler. 

Town staff has collaborated with a local engineering firm, Resource Engineering Group (REG), to develop options for both interior and exterior energy mitigation for new construction and large renovations.

Exterior energy mitigation

To address energy use from exterior energy systems, such as snowmelt, outdoor gas fireplaces, large hot tubs and pools, Hessler said the town could implement an Exterior Energy Offset Program (EEOP). She said many Colorado mountain communities have EEOPs to help offset the excessive energy used for these exterior systems and mitigate potential greenhouse gas emissions.

“Outdoor energy systems, like snowmelt driveways, spas and heat tape, are energy intensive,” she said. “For example, snowmelt systems use twice as much energy per square foot as indoor heating systems.”

“A study in Crested Butte done by REG found that using snow removal equipment like snowblowers or plows is 100 times less carbon-intensive than snowmelt systems,” said Hessler.

EEOP compliance could include onsite mitigation, such as installing renewable energy systems like onsite solar panels. If onsite mitigation isn’t feasible, the town could implement an offset fee based on the energy use of the outdoor system. “The fee is based on the cost of installing solar electric panels (PV) which produce sufficient energy to offset the annual energy consumption of the given exterior energy uses,” said Hessler. “Any fees collected for exterior energy mitigation would be used to provide a funding mechanism for energy efficiency and renewable energy programs in Mt. CB.”

Potential programs that could be funded by EEOP offset fees could include energy efficiency upgrades for local programs like GV-HEAT, solar installations for affordable housing projects like Homestead, energy efficiency rebates for residents and community renewable energy projects. 

“Do you have a sense as to how many projects would fall under that EEOP umbrella?” asked councilmember Valeda Scribner.  

“Heated driveways are starting to become more of a luxury and not just for safety for steep driveways,” said community development coordinator Todd Carroll. He noted that a handful of heated driveways have been installed over the past year in the town. 

Interior energy mitigation

Hessler also suggested the town implement an interior energy mitigation program that increases the energy efficiency of new residential construction and major renovations. 

She explained that the town has several different levels of requirements to consider, including whether to require the energy efficiency measures to apply to all new residential construction, or only to larger single-family homes. 

For larger single-family home builders, the council could decide on a square footage trigger requirement, such as new homes over 5,000 square feet. “Bigger homes are huge users,” said August Hasz from REG. “That’s driven by a number of factors. A lot of them have really advanced EV systems or security systems. And property managers are definitely afraid of a broken pipe, so they’re actually usually not set colder when they’re not being lived in.”

If the council wants to mitigate energy use in all new residential construction, the town could require that new builds get an energy rating with the Home Energy Rating System (HERS) and an energy assessment before issuing the certificate of occupancy. “It would not require any above-code or added efficiencies, however, incorporating energy modeling into the design and construction of a building may incentivize more sustainable building practices,” said Hessler. “Additionally, modeling provides a more accurate assessment of a building’s energy efficiency, which is particularly beneficial for larger homes that often have complex designs and energy systems.”

Another option is to require that new builds also meet higher energy performance standards. “This would require the above energy modeling, as well as a percentage improvement upon the current building codes, which could be achieved via on-site solar, improvements to the building envelope, mechanical systems, etc.” Hessler said the council would determine the required percentage improvement, as well as how often to strengthen the requirements.

The next step will be to have one or more work sessions in January to get into the nitty-gritty of the interior and exterior energy mitigation programs. The council could start with initiating an EEOP first, or develop the interior program in tandem. “We’ll look at what kind of systems do we want to mitigate, different offset requirements, where we will spend that offset mitigation funding, etc.” said Hessler. 

“I’m a yes on both,” said councilmember Steve Morris. The rest of the council agreed.

“It seems a lot of us are on the same page,” said councilmember Alec Lindeman, but he also wanted to consider how these plans could impact the increasing costs to build in the town. “I personally know people who were priced out from what their intended plan was to build in this valley.”

“I’d be curious to hear more information on what the internal standards would be,” said councilmember Roman Kolodziej. “Are we talking about more efficient windows, or are the lights on in the house that’s actually occupied two weeks of the year?”

Councilmember Bobbie Sferra also suggested looking into some sort of tax or mitigation for empty houses that use lots of energy. “Maybe it would inspire people to rent out their house,” she said.

“Why focus entirely on new builds and renovations and not include existing buildings in this conversation at all?” asked Scribner. “Why do we have to draw the line, especially if we’re going    to be establishing this framework and methodology? There could be an advantage to somehow include existing buildings as well.”

“This is just one pathway. This is the low-hanging fruit as far as mitigating energy use,” explained Hessler. “Focusing on existing construction and other buildings is kind of a separate conversation. Tackling our existing building stock, in which a lot of it is quite old and takes more energy, that is quite a bit more challenging. So this is step one.”

Hessler noted that the town is still partnering with GV-HEAT, which works with residents to identify and implement home energy efficiency upgrades to help reduce their home energy costs. GV-HEAT completed 15 retrofits in Mt. Crested Butte in 2024. 

Town staff and the council will continue the discussion and get into the details of initiating the programs at a future work session.