Correction: This article has been updated to clarify that the amended town code does not permit ADUs in River Valley Ranch, Hendrick Ranch and Roaring Fork Village, as mistakenly stated. Zoning restrictions in these neighborhoods must be amended to permit ADUs.
The Carbondale Board of Trustees streamlined the process by which residents can add accessory dwelling units (ADUs) to their properties.
The board unanimously approved an ordinance at the Tuesday, April 14 meeting amending town code to minimize the ADU review process. The amendment expanded residential districts in which ADUs are permitted, increased the number of bedrooms permitted per ADU and loosened ADU dimension limits and parking restrictions.
The amended code also allows the Board of Trustees to initiate the ADU zoning process.
“Our goal here has been to streamline the process for adding accessory dwelling units to allow for housing as infill,” Carbondale Mayor Ben Bohmfalk said.
The ordinance amending the code cites a “significant and growing housing deficit” in Carbondale, specifically to households earning below the area median income (AMI). It recognizes ADUs as “a tool to provide incremental housing opportunities within existing neighborhoods, while ensuring compatibility with surrounding development and minimizing impact on adjacent properties.”
According to a report by the Garfield County Housing Authority, the 2025 AMI for a one-person household in Carbondale was $105,600 and the 2025 AMI for a four-person household in Carbondale was $128,100.
The amended code reduces the ADU review process by only requiring that proposed ADUs undergo an administrative site review plan by staff, a less arduous review process than the minor site plan review by the Planning & Zoning Commission previously required.
The trustees also reduced the review processes to install ADUs in specific areas of town. ADUs are now fully permitted in Carbondale’s Old Town Residential zone, encompassing 16 downtown blocks south of Main Street. They were previously permitted under special use, requiring more extensive review processes.
ADUs in the town’s Residential/Low Density areas — including parts of southeast and northeast Carbondale — were amended to permitted use rather than conditional use, also reducing the review processes required.
ADUs in Carbondale’s Residential/Medium Density zone, including a series of blocks scattered on either side of Main Street, were also amended to permitted use rather than conditional use. The code amendment, additionally, permits ADUs in agricultural zones.
The amendment allows ADUs to contain two bedrooms rather than one bedroom and increases the maximum size of ADUs to 1,000 square feet, depending on the primary structure’s footprint size, rather than 850 square feet.
The trustees also loosened ADU restrictions on parking. Studios and one-bedroom ADUs are no longer required to provide off-street parking spaces, while two-bedroom ADUs are required to provide just one off-street space. All ADUs were previously required to provide one-to-two off-street parking spaces.
Trustee Chris Hassig questioned the effect the ADU code amendment would have on the proliferation of short-term rentals, ultimately suggesting the possibility of regulating short-term rentals through ADU regulations rather than through zoning regulations. But he added that he thinks the town is “good where we are” on the code amendment.
Bohmfalk said the town can analyze the effect the ADU code amendment has on short-term rentals through annual data collection.
“We can watch, and say, ‘Oh my gosh, we approved 10 ADUs, and they all become short term rentals, and that’s not exactly what we were thinking,’” he said. “But we have heard there needs to be a balance, and we need more beds, so I think that’s a very nimble way to do it.”
In other news …
The Board of Trustees reviewed an update regarding the opening of the Carbondale Aquatic Center. Town staff and contractors told the board that the center will open to the public at noon on May 23.
The board also unanimously approved an ordinance expanding the definition of Carbondale’s Historic Downtown Area to include properties in the Historic Commercial Core, encompassing blocks on both sides of Main Street, as well as Old Town Residential, the series of blocks south of Main Street. The ordinance requires projects that fall within the Historic Downtown Area — including the Historic Commercial Core, Old Town Residential and what the town defines as “structures of merit” — undergo a courtesy review.