To comply with state legislation requiring accessory dwelling units in districts zoned as single-family residential, the Louisville Planning Commission has reviewed and amended a draft ordinance that allows for the smaller residences.

Colorado House Bill 24-1152 requires municipalities to allow accessory dwelling units, or ADUs, in all single-family zoning districts by June 30.

ADUs are internal, attached or detached dwellings that are independent from the primary residence, but still on the same lot. The ADU provides places for living, sleeping, eating, cooking and sanitation.

The Louisville City Council is scheduled to hold a public hearing on the proposed ordinance to allow ADUs at its April 15 meeting.

The current city code does not address ADUs, and they are not currently allowed. The code does provide for guest homes, which can’t be rented, sold or have full kitchens. Short-term rentals are currently not permitted in Louisville, and could not function out of an ADU.

At the Thursday planning commission meeting, Planning Manager Jeff Hirt said city staff reached out to neighborhoods affected by the Marshall Fire in 2023 to get resident input on ADUs.

“The state law really overrides a lot of the questions that we asked during that survey,” Hirt said.

Hirt said there were a lot of mixed opinions on ADUs, with some residents not wanting ADUs to be allowed.

Under state statute, there are ADU standards all cities must comply with, but the city still has leeway to create Louisville-specific regulations. While the bill does allow the requirement of a historic preservation review for an ADU, Louisville cannot require ADUs to be approved through a discretionary process, such as ensuring the ADU is “consistent with neighborhood character.”Any ADU standards a city places must employ objective metrics. Homeowners associations are not allowed to prohibit ADUs, under the law.

A city also cannot require the owner of the ADU to live in the same lot, except at the time of permitting of the ADU. The city’s draft regulations also require parking only if there is no spare parking spot for the primary unit or if on-street parking where the ADU is located is prohibited.

The ordinance only allows ADUs to be built on single-family dwelling unit lots, and duplexes or other multi-family units would not be allowed to build an ADU.

Community Development Director Rob Zuccaro said the state only mandates ADUs on single-family housing units, but the city could look into allowing ADUs on multi-family dwellings units.

Hirt clarified that once the ordinance is formally approved by the City Council, there would be a grace period where residents who have a unit that meets the definition of an ADU, but are nonconforming, could get grandfathered into the ordinance.

“The intent is to have a lot of flexibility to bring those units into full compliance, it considers legal nonconforming, meaning they are not in violation of the code,” Hirt said.

The commission discussed how the council should consider finding a way to lower the cost for water tap fees for new ADUs, in the hopes that by lowering the water tap fees they can lower the obstacles in order to allow residents to reasonably build ADUs.

The commission approved sending the draft ordinance to the City Council with the condition that for ADUs demonstrating a design for accessibility accommodations, the ADU could get an increase on lot coverage and square footage. The increase of the lot would vary on whether the unit is detached or attached.