Foreign chanceries and missions should be encouraged to locate along four of the city's great avenues - Massachusetts, Connecticut, parts of Wisconsin and 16th Street - and should be kept out of more residential sections of Washington.

This is the central recommendation of a draft proposal scheduled for release today by the National Capital Planning Commission, the federal government's planning agency for the metropolitan area.

In line with the recommendation, which was developed by the NCPC's planning staff and will not be formally acted on for about six months by the planning commissioners, McLean Gardens along Wisconsin Avenue NW north of the Cathedral is ruled out as an appropriate site for a chancery-embassy complex.

The owners of McLean Gardens, one of the largest moderate income rental complexes in Northwest Washington, announced plans over a year ago to demolish the Garden's 723 apartments to make way for a $150 million development on the 33-acre site.

CBI-Fairmax Corp., owner of McLean Gardens, announced at the time that it hoped to build an elaborate diplomatic enclave with apartments, shops, international boutiques and nine to 16 embassies and chanceries, Residents of McLean Gardens have been fighting the plan since it was annnounced.

Yesterday, R. Robert Linowes, attorney for CBI-Fairmac, said he had not seen the NCPC proposal but was generally aware of its recommendation. "It's just the staff position. The NCPC hasn't acted yet," Linoweas said.

He pointed out that, even if the NCPC commissioners approve the proposal in its present form, the D.C. Zoning Commission has to approve it before it becomees part of the city's comprehensive plan. The zoning commission, Linowes said, "will get the facts. From us, the course."

Whatever the final form of the NCPC's policy, the proposal to be released today is thought to be the first time an official planning agency has recommended that diplomatic buildings he concentrated along certain major arteries - where they have been traditionally located.

That tradition has been changing in recent years, however, because suitable and available sites have not been readily available along Embassy Row (Massachusetts Avenue) and Connecticut Avenue - the areas most preferred by foreign nations for their offices in Washington.

Foreign government office buildings have been spilling over into residential areas of the Northwest, according to an NCPC report accompanying its proposal for the comprehensive plan. Homeowners often oppose chanceries in their neighborhoods because of the traffic parking and other problems associated with what are essentially office buildings.

There is far less opposition to embassies where the ambassador or chief of mission actually lives and entertains. The NCP proposal would not discourage embassies from locating in residential areas of the city.

Specifially, the NCPC suggests that foreign nations be encouraged to locate their offices along massachusetts Avenue NW from 2d Street NW, near the Capitol, to the Naval Observatory; along Connecticut Avenue, including land near Van Ness Street NW that has been set aside by the U.S. government for chancery sites; along 16th Street NW; and along Wisconsin Avenue NW between the Whitehaven Parkway and the National Cathedral.

At present, there are official foreign government buildings, either existing or under construction, in all of these areas except along Massachusetts Avenue east of Scott Circle and west of 3rd Street NW.

New chancery development in this area could contribute "to the revitalization of this section of the Downtown Urban Renewal Area and promote an international image and unique character for this section of Massachusetts Avenue," the NCPC said.

Sixteenth Street, on the other hand, was once the most popular place for embassies and chanceries to be located. It has, however, lost about half of the 30 major foreign installations that had 16th Street addresses as recently as 1965.

"Special efforts are needed to retain the existing chanceries and embassies and to attract additional ones to this area as an aid in preserving and enhancing this historically significant street and entrance to the nation's capital," the NCPC said. Sixteenth Street's "early prominence as a prestigious location for diplomatic activities and ambassador's residences should be restored."

The NCPC also recommended that the many international organizations such as the World Bank, located in the area of K and 17th Streets NW should be encouraged to remain and expand near their present sites.

The NCPC found that as many as 15 embassies have moved from the District to the suburbs, mostly Montgomery County, over the past 10 years. While most diplomatic buildings remain in the city, the NCPC report found that foreign nations have experienced increasing difficulty in recent years trying to find desirable sites they can afford.

Statistics compiled by the NCPC suggests that it is in the economic interest of the District to keep as many foreign missions within the city's limits as possible. In 1975, there were 130 missions in Washington, compared with 72 in 1950, employing 6,850 persons in 1975, compared with 3,400 a quarter century earlier.