The D.C. Zoning Commission delayed indefinitely this week a vote on a proposal to regulate the locations of fast food restaurants.

Meanwhile, construction of such a restaurant began recently at 4925 South Dakota Ave. NE. The restaurant would be prohibited under the proposed regulations.

The delay, which occurred at the commission's Monday meeting, marked the fifth time in a year that the commission put off a final vote on the regulations, which have undergone several rewritings since they were first proposed by a community group two years ago.

The latest delay came after Andrea Johnson of the city's legal office said that the city's lawyers needed more time to review the regulations. She said she was concerned that the regulations would be difficult to enforce, principally because of the way fast food restaurants are defined in the regulations.

"When a builder applies for a permit, that application does not ordinarily show whether a restaurant will prepare food in advance, which is one of the ways [the regulations] define a fast food restaurant," said Steven Sher, executive director to the Zoning Commission.

Zoning commissioner Lindsley Williams complained the corporation counsel should have finished its review because the regulations had been published March 1, in the D.C. Register, the city's official publication.

The previous delays were also attributable largely to the problem of defining a fast food restaurant so that it applied only to the national chains and not to small, locally owned carryouts.

Local lawyers hired by the national chains have persuaded the commission to continue to tinker with the definition.

More than 30 fast food restaurants have opened in the District since the zoning commission began working on the regulations. There are about 130 fast food restaurants in the city.