Planning Commission rejects home size limit proposal

The Boulder County Planning Commission voted unanimously to recommend denial of proposed text amendments to the Land Use Code that would have placed stricter limits on residential home sizes in unincorporated areas of the county.

After four hours of testimony on March 19, during which the Planning Commission heard staff presentations, asked questions, and listened to extensive public testimony, the commissioners unanimously recommended that the Board of County Commissioners reject Docket DC-24-0003, which would have modified the Site Plan Review process.

The proposed amendments sought to eliminate the current "presumed compatible size" of 125% of a neighborhood's median residential floor area (RFA) which would have fundamentally changed how the county regulates home sizes, transforming what had been a presumption that could potentially be overcome in certain circumstances into a strict limit based on the median RFA of each defined neighborhood.

A key feature of the proposal was a sliding scale system designed to address concerns that the median-based limit would disproportionately impact residents with smaller homes. Under this system, parcels with existing homes smaller than 4,500 square feet would receive additional RFA allowances beyond the neighborhood median.

For example, in a neighborhood with a 3,200 square-foot median, a property with an existing 1,400 square foot home could build up to 3,200 square feet, while a property with a 2,700 square foot home could build up to 3,450 square feet. Properties with existing homes exceeding 4,500 square feet would not qualify for additional RFA unless they met specific exemption requirements.

Other elements included exemptions for properties with conservation easements, historical structures, energy efficiency retrofits, and certain rebuilds. The amendments would have applied to all parcels in unincorporated Boulder County, including subdivisions in Niwot and Gunbarrel platted after 1994 that are currently exempted from Site Plan Review.

"While this commission supports the goals of neighborhood character, sustainability, and affordability, we recommend that the county commissioners deny approval," said Planning Commissioner Mark Bloomfield in his motion to deny the amendment. The commission also requested that a moratorium on residential construction exceeding median neighborhood size be immediately lifted while staff explore "further ways of meeting the three goals more equitably and fairly."

The proposed amendments, presented by Long Range Planner Ethan Abner, were developed after the Board of County Commissioners expressed concerns with increasing house sizes and the rate at which they were growing in unincorporated Boulder County.

Abner cited data showing that new homes in unincorporated Boulder County average 3,900 square feet compared to the national average of 2,417 square feet, with some county permits seeking up to 4,733 square feet when including garages and unfinished basements. Staff argued that larger homes have greater climate impacts both in construction materials and ongoing energy use.

However, the proposal faced significant opposition during public testimony, with architects, builders, homeowners, and realtors expressing concerns. In addition, many Boulder County residents expressed their opposition in written responses to the proposal.

Scott Rodwin, coordinating testimony for several professional organizations representing about 10,000 members, claimed the process had a "preordained conclusion" and disputed the energy efficiency arguments, noting that "Boulder County requires that bigger houses use less energy per square foot."

Several commissioners expressed concerns about the proposal's approach. Planning Commissioner Gavin McMillan suggested moving away from using neighborhood medians. Planning Commissioner Rachel Lee supported creating size limits but wanted them to be "fair and well-defined," while Commissioner Kominek favored a county-wide cap rather than neighborhood-specific limits.

The Board of County Commissioners, which originally authorized staff to pursue the text amendments in September 2024 and imposed a six-month moratorium on exceeding median neighborhood sizes in January 2025, will now consider the Planning Commission's recommendation at an upcoming hearing, with the date to be determined.