The District of Columbia Zoning Commission is expected to finish hearings next week on widespread changes proposed in the city's parking and loading requirements, including the easing of parking requirements for new buildings close to Metro stops.

The proposals, by the D.C. Department of Transportation, represent the first comprehensive look at parking and loading in nearly 25 years, a period during which significant changes in land use and transportation patterns have occurred in the District.

Sarah Campbell, assistant director of DC DOT for policy and program development, said the zoning proposals attempt to reflect the changes that have taken place since 1958, when most of the existing requirements were established. These changes include construction of the area's subway system; significantly less dependence on the automobile than was anticipated; the smaller automobiles being driven by Americans--and particularly by Washingtonians; the larger commercial vehicles being used today; and increasing emphasis on the efficient use of public and private space.

To reflect use of the expanding subway system, for instance, the proposed zoning revisions would allow developers to reduce by 25 percent the amount of parking space required in a nonresidential building if the building, in a business area, is within 800 feet of a Metrorail entrance. Under the proposal, the Board of Zoning Adjustment would be given the authority to reduce or eliminate altogether the amount of required parking space for nonresidential buildings that are directly connected to a Metrorail station.

The downsizing of cars since 1958 is also acknowledged in the parking proposals. DOT has suggested that a parking lot or garage with more than 25 required spaces be allowed to designate up to 40 percent of them for compact cars. The compact spaces would be smaller: 8 feet wide by 16 feet long under the proposal, compared with the 9-by-19-foot dimensions required for other spaces.

The smaller parking spaces proposed, which reflect the proliferation of smaller cars, follow similar action in other jurisdictions. A recent article in Urban Land noted that 40.5 percent of the autombiles in use in the District of Columbia in 1981 were classified as small cars; only 11 states ran ahead of the District in small-car use.

(The article, by Richard F. Roti, a parking consultant, suggested that a 7 1/2 foot wide stall for small cars would be prefereable because an eight-foot one encourages misuse by large cars, he wrote.)

Recognizing an increased use of bicycles for city travel, the proposed regulations would require, for the first time, bicycle parking spaces for offices and retail buildings. The new rules would require a building to provide a minimum number of inside bicycle parking spaces equal to 5 percent of the number of required automobile spaces. A certain number of spaces would have to be provided even if no auto parking spaces are required.

The proposal outlines the number of parking spaces that would be required for different kinds of buildings in different areas; in some cases, it affords the developers more flexibility, in some cases less.

For example, where parking spaces would fulfill two or more uses or buildings, the Board of Zoning Adjustment would be authorized to reduce the number of spaces by up to half if, say, one use would take place at night and another in the daytime. An office building sharing a parking lot with a theatre would come under this section.

In contrast, the new regulations would impose minimum parking requirements for buildings in the central business district and the Pennsylvania Avenue Development area for the first time.

The proposed amendments recommend that additional parking and loading spaces not be required for historic buildings or landmarks more than 50 years old that are located in an historic district. Added spaces would be required if the structure is renovated and increased by more than 25 percent in gross floor area. These provisions were called "too restrictive" by the Board of Trade, which suggested that buildings that contribute to the historic district, whatever their age, and historic buildings outside a historic district be spared any additional parking and loading requirements.

Another provision would, if adopted, require hotels to provide off-street parking places for tour and charter buses--a minimum of one space for every 100 sleeping rooms, up to a total of six bus spaces. The spaces could be located away from the hotel within four miles as long as they were still in the District and not in a residential area.

Some controversial provisions would affect the city's alley system. For instance, the proposal would require a developer to bring an alley up to "improved" status when a new building will use the alley for access. The proposal also would require that alleys that are now narrower than the required size, be widened through the granting of an easement or dedication of land--a provision the Board of Trade contends the commission has no authority to adopt.

The proposal also would set new requirements for loading berths and platforms and for delivery van parking spaces for new and renovated buildings. The proposals are designed to reflect the different size trucks in use today and the fact that different size trucks are used for different commercial purposes, the District's Campbell said.

Hearings on the proposed zoning changes, which started in November, continue and could conclude on Monday, according to Steven Sher, executive secretary of the Zoning Commission. The five-member agency then will begin assessing and weighing everything it heard and try to come to some resolution. There are so many complicated issues that it will take a substantial amount of consideration, he said, "several, maybe many, months."