The Mason Planning Board is preparing to bring a zoning ordinance amendment that will permit residents to have a detached accessory dwelling unit (ADU) on their property to next year’s Town Meeting.

Accessory dwelling units are apartments built on the same lot as an existing primary residence. They can be attached to the main home, or detached from it, with size based on a specific square footage or a percentage of the existing home. Currently, Mason’s zoning ordinance allows attached ADUs, and at Wednesday night’s Planning Board meeting, members held a preliminary discussion on how to best move forward with an amendment. 

Cassie Cashin, a regional planner with the Nashua Regional Planning Commission, suggested that they look to towns like Lyndeborough, where residents recently voted in favor of permitting detached ADUs, for guidance on how to structure the amendment. She will also be compiling a list of other towns that allow detached ADUs for further insight to determine which method would work best for Mason.

Selectman Charlie Moser noted that while many towns require that a property owner apply for a license to have a detached ADU, that might not be the best method for Mason since the town lacks the necessary infrastructure.

“We don’t have the staff – an administrative structure just doesn’t make sense,” he said. 

Instead, the town could consider allowing detached ADUs either by right, variance or special exception. Cashin noted that towns which allow detached ADUs by right usually require that the property owner to apply for a building permit. In that case, a building inspector would inspect the ADU in the same way as a main residential building. 

Since the town already has a building permit and inspection system in place, Moser expressed interest in potentially going that route.

“A lot of towns do that, and it works fine,” Cashin said. “It eliminates a lot of paperwork and procedure.”

The board also discussed holding at least two public hearings for Mason residents to voice their input on the proposed amendment.

Vice Chair Dane Rota suggested the board look to the language in the ordinance allowing attached ADUs to use in the proposed amendment. He told the other board members they should review the current ordinance and prepare for a more-detailed discussion of the issue during next month’s meeting.