Planning commission hears public comment on draft accessory-apartment rules; leaves record open

The St. Mary’s County Planning Commission on a February 2008 public hearing considered a proposed text amendment to the county zoning ordinance that would change how accessory dwelling units are defined, sized and sited.

County land-use staffer Yvonne Chalay said the amendment, introduced to the Board of County Commissioners in September 2007 and revised in December, would change the name “accessory dwelling unit” to “accessory apartment” and set a maximum size standard intended to preserve the accessory — not duplex — appearance. “Tonight’s amendment … is an amendment to the comprehensive zoning ordinance to change the criteria for an accessory dwelling unit,” Chalay said.

The proposal would keep the current 300-square-foot minimum for an accessory unit but replace the current 30%-of-principal-dwelling cap with a numeric cap: 30% of the principal dwelling or 600 square feet, whichever is less, for units inside a principal structure; and 50% of a detached accessory structure or 600 square feet, whichever is less, for detached accessory apartments. Staff said garages and attached garages would not be counted toward a principal dwelling’s gross floor area when calculating percentages. The draft also would require an accessory apartment inside a principal dwelling to share at least one wall with the principal living space; separate entrances to accessory apartments must be secondary and on the side or rear, not facing the street except on some corner lots.

Why it matters: staff said the change responds to complaints about large houses constructed with sizable accessory units that give the appearance and market intent of duplexes. Chalay explained staff initially considered an owner-occupancy requirement but rejected it because such a requirement would be difficult to enforce and could conflict with local housing realities (for example, military households who temporarily rent while deployed). Instead the county is seeking rules that make an accessory unit clearly subordinate by size and appearance.

Residents, builders and homeowners’ representatives who spoke offered a range of concerns. Larry Aldridge, who gave his address to the commission, said a 600-square-foot cap would be too small for many practical caregiving arrangements: “600 square feet doesn’t do it. You can’t put 2 bedrooms, a 32-inch wide door, wheelchair, that type of thing.” Keenan James, a resident and homeowners-association board member, said his neighborhood has multiple homes built by a developer with accessory apartments that “take on the appearance of a duplex” and that created worries about density, school access and property values. “This was very much a surprise to many of the home buyers,” James said.

Builder and contractor Rick Benafield urged care with code terminology. He told the commission that changing the label from “accessory dwelling unit” to “accessory apartment” could create building-code complications because the International Building Code (IBC) and International Residential Code (IRC) use different definitions and requirements. Benafield recommended using precedents and examples to guide any size cap; his practical sense was an 800-square-foot target “is probably a good starting point” for many accessory apartments.

Commission discussion focused on several recurring points raised by staff and the public: maximum size, how to measure gross floor area (the ordinance references measurement from exterior faces and excludes floor area with less than 6-foot ceiling height), wheelchair/ADA access considerations, whether a detached accessory structure could be mostly living space rather than accessory (staff said the 50% rule was intended to prevent that), and the potential for developers to build “starter” garage/apartment combinations that later become principal dwellings.

Staff emphasized enforcement and permitting changes that would accompany the text amendment: all accessory apartments would require building permits through the Department of Land Use and Growth Management, be limited to one per lot, and include an additional independently accessible parking space. Chalay said staff is “open to recommendations” on the numeric cap and on other technical details.

The public hearing was left open for additional written and oral comments. The commission voted to continue the public hearing and keep the record open for additional input and follow-up, and indicated it would next consider continuing the item at the March 10 meeting. The commission asked staff to return with clarifying materials, examples of completed accessory apartments, and language options for the size cap and appearance standards.

Ending: Commissioners and staff signaled they want clearer language on size measurement, ADA/accessibility implications, and how permitted accessory apartments would affect adequate-public-facilities calculations and neighborhood character. The record remains open for further written comment and examples; staff will return with revisions and additional information at a later meeting.