Montgomery County lawmakers are looking into legislation that would require homeowners with guesthouses to get a license to build that extra space.

After neighbors complained about a woman who wanted to build a guesthouse on her property where she could live temporarily while renting out the main home, county officials decided to redefine what makes a guest home, as well as license the structures to better monitor them.

The County Council's Planning, Housing and Economic Development Committee proposed classifying guest homes as accessory apartments, which would require homeowners with guesthouses to get a license for the space regardless of whether they were renting it out.

Accessory apartments are living spaces, either inside or outside the house, which homeowners can rent to no more than two adults.

Legislative Attorney Jeff Zyontz said because guest homes were allowed under current zoning code and were not required to be licensed, homeowners might have been using them as illegal rental spaces. It's difficult for officials to know exactly how many guest homes are in the county, he added.

"Because it's a permitted use, and it's an accessory building, we don't keep track," he said, saying permitted accessory buildings also include garages and sheds.

Under the proposed legislation, building a guesthouse would fall under the same requirements for building an accessory apartment -- including that the space couldn't be larger than half the size of the main house. Currently, a guesthouse is defined as a space with sewage, water and cooking capabilities where a person stays no more than six months and doesn't pay rent.

Requiring a license for the homes would allow the county to keep track of the number of spaces, as well as potentially catch those who are illegally renting them out, Zyontz said.

Councilman Marc Elrich, D-at large, said the situation came to light because the code didn't define who was allowed to occupy a guest home -- only the occupant as a visitor. By licensing guesthouses as accessory apartments, the county could better define who could live there.

"It accomplishes what we thought the common understanding of the law was," he said.