Residents looking to expand their existing homes or replace them with larger ones will need to conform to new limits as Boulder County officials look to slow a trend toward larger house sizes in unincorporated parts of the county.

The Boulder County commissioners recently voted 2-1 to approve new residential size limits for site plan reviews for homes in unincorporated Boulder County. They also voted unanimously to end a temporary moratorium on applications for homes bigger than the median square footage for the neighborhood. The newly approved size limitations, which only apply to homes in unincorporated parts of Boulder County, go into effect May 13.

People rebuilding homes that were destroyed by the Marshall Fire in December 2021 are exempt from the changes through March 2027. Projects approved prior to May 13 also won’t be impacted by the changes. More than 1,000 homes were burned down in the Marshall Fire, which also killed two people and caused more than $2 billion in damage.

Most of the people who spoke at the commissioner meeting urged the commissioners to vote against the proposal, citing concerns that included the potential to perpetuate economic inequality by disproportionately restricting home sizes in neighborhoods with smaller homes.

The commissioners last year asked the county’s planning staff members to look into updating the land use code based on concerns that increasing home sizes could make housing across the county more expensive and less sustainable. Larger homes may impact the rural feel of unincorporated Boulder County and increase property taxes in the nearby area, according to county materials. They also typically leave a larger carbon footprint than smaller homes.

The county’s previous policy typically allowed homes of up to 125% of the median residential floor area in the surrounding neighborhood to be built, though larger homes had sometimes been allowed.

Generally, the new code replaces that policy with one that limits structure size to the median residential floor area of the surrounding neighborhood. The new policy includes a sliding-scale concept that grants applicants an additional floor area amount if their parcel approaches the structure size limit that’s established in the zoning district standards.

Speakers at the meeting included architects, real estate agents, home builders and property owners. Some property owners said the moratorium would scuttle plans for their dream homes, while others said they believed Boulder County had stringent enough green building requirements to offset negative climate impacts of bigger homes.

Scott Rodwin, owner of Rodwin Architecture, said the building rules were already tough enough to meet the county’s stated goals, including around sustainability. The new rules, he said, will discourage building altogether.

“It has a direct impact because these are houses that are not going to get built or houses that are not going to get expanded or remodeled right now,” he said. “People are losing their jobs over it.”

Paula Shuler, who has lived on an agricultural property on Niwot Road for 30 years, said the new rules exclude a newer, nearby subdivision from the median residential floor area calculations for her property. The result, she said, is she will lose 800 square feet from a planned addition to accommodate her disabled brother.

“The changes being proposed are a knee-jerk reaction and too drastic,” she said.

Commissioner Claire Levy said she was convinced to vote “no” on the changes by the arguments around a lack of equity for those in neighborhoods with smaller properties.

“I’m concerned about the disparity in neighborhoods across Boulder County,” she said. “It really takes away value and reduces resale value and reduces what they can achieve in a place they made the largest investment they’ll probably ever make.”

She added that she’s not convinced the changes will impact affordability.

“I don’t think we are really going to bend the curve on the cost of housing in Boulder County through site plan review,” she said.

But Commissioners Marta Loachamin and Ashley Stolzmann said the changes should provide more certainty in the review process, preserve neighborhood character, slow the loss of more modestly sized homes that contribute to overall housing affordability, and help the county meet its sustainability objectives.

“We’re trying to address some of these issues of sustainability and affordability,” Loachamin said. “This is one piece of that work.”