Harrisville planning commission begins drafting ADU ordinance; parking, size and infrastructure top concerns

The Harrisville Planning Commission spent the bulk of the meeting on a detailed discussion of accessory dwelling units (ADUs) as part of a proposed general plan amendment and ordinance. Staff (identified in the record as Sarah) walked commissioners through types of ADUs (internal, attached, detached), recommended guardrails to keep ADUs subordinate to primary dwellings, and flagged policy choices commissioners must decide before staff drafts ordinance language.

Key issues under discussion included how many ADUs should be allowed per lot, lot-size thresholds, maximum ADU sizing, height and story limits, parking minimums, design guidance, and utility and impact-fee policy. Sarah recommended allowing one ADU per lot in most cases and noted infrastructure concerns if housing capacity increases without corresponding utility upgrades. "Most cities allow just one," she said while outlining factors such as lot size, setbacks and parking that could justify exceptions. She urged a minimum lot-size threshold (6,000 square feet was discussed) and proposed size limits that would prevent an ADU from exceeding the primary dwelling or a fixed percentage of lot area — staff framed that as "no more than 10% of a lot area or the gross floor area of the primary dwelling, whichever is less."

On design and privacy, staff recommended that detached ADUs placed outside normal setbacks should have no windows or openings on the side adjacent to another property, or otherwise provide privacy screening so the structure functions like an accessory building rather than a second house. For height, staff suggested limiting most ADUs to single-story with attic access, reserving two-story ADUs for very large parcels or limiting their square footage to keep them visually subordinate.

Parking proved a central concern. Staff noted state constraints on what local governments can require for internal ADUs but recommended a local standard of one off-street parking space for internal ADUs and two off-street spaces for attached/detached ADUs larger than 600 square feet. Commissioners debated whether requiring two spaces for larger ADUs would discourage conversions of basements and limit affordability; several members said one space was likely sufficient for many situations, while staff warned about street-parking pressure in winter when on-street parking is restricted.

Utility capacity and impact fees were discussed at length. Staff warned that if the city does not require appropriate impact fees when new services are needed, current residents could bear the cost through tax-funded upgrades. Commissioners asked staff to consult utility providers about separate meters and the fiscal implication of allowing ADUs at scale.

Commissioners asked for a draft ordinance that would incorporate these recommendations and return for a work session and public hearing. Staff also proposed incentives and outreach — for example, a good-landlord training discount — to encourage registration of existing internal ADUs that currently operate without permits. The commission agreed staff would draft ordinance language reflecting the input and bring it back for more detailed review and public input in a future work session and public hearing.