ABOUT THE TURN of the 19th century, one diplomat described Washington as a city of "magnificent distances" -- which is protocol talk meaning civilized housing here was few and far between. Today the embassy housing shortage is worse than ever. Embassies -- with their needs for office space, entertaining room and an impressive presence -- have always had a hard time finding a home in Washington. A bill currently before the Mayor, and opposed by the State Department, would ban any more embassies from building on Washington's embassy rows -- Massachusetts Avenue and 16th Street. It would also keep them from additions or alternations.

Today there are 140 diplomatic missions in Washington, up from 129 in 1976, and almost three times the number that existed before World War II.

The only government-sponsored diplomatic enclave is on upper Connecticut Avenue, the International Center. About a decade ago, the National Capital Planning Commission finally made available 31.5 acres, part of the old Bureau of Standards location.

The site is adjacent to the University ofthe District of Columbia and across from the Van Ness shopping center and apartment development. The area was laid out to hold 14 chanceries on a steep 19.7 acres, around a central park, with another 11.8 acres reserved for an Organization of American States building. The site plan was designed by Edward Durrell Stone Jr.

Since then, the OAS has built nearer the Pan American Union building. Their 11.8 acres may be used for more chancery sites and/or another international organization.

The State Department, according to Deputy Chief of Protocol Richard Gookin, is interested in another 11 acres behind the UDC buildings. "We have at least another six nations who have asked us to find them space to build chanceries."

Seven countries have plunked down their money -- $12.50 to $15 a square foot for the International Center lots. Several more are in negotiation, Gookin said.

Of the seven, five have had their plans approved by the State Department, the Fine Arts Commission and the Capital Planning commission. (Jordan and Libya are still pending.) The israeli chancery is underway, and expected to be occupied in fall 1980. The Yemen chancery bids have been opened and construction should start soon. The others aren't as far along.

The public will have a chance to look at the plans for Bahrain, Israel, Kuwait, Yemen and Ghana at a show of models, elevation drawings and other sketches of the five opening at The Octagon (1799 New York Ave.) Tuesday. The Show continues through Dec. 30, curated by David Schaff, and architectural historian, and sponsored by the American Institute of Architects Foundation.

The five chanceries planned for the International Center have several points in common.Only one or two seemed to make any bow at all to energy efficency. But then, several of the countries have plenty of oil at home if they run out. All are planned for large entertainments, signalling a shift away from the old custom of parties in the ambassador's residence.

The sites are all difficult. There is little level land, all the lots slope steeply, precipitously. And all the lots are relatively small.

The architects faced another problem: how to build a structure that recalls the country's native architecture, without, as Paul Vieyra of Skidmore, Owings & Merrill put it, "making a Disneyland."

The chanceries, though technically foreign soil, are not geographically in their homeland. They have to conform to the climate and the customs of the United States. It's rather like learning enough of a foreign language to make yourself understood, while keeping the soft tones of your own accent. And, of course, in all these buildings, the architects are American, though many have long experience in other countries.

All except the Kuwait (which makes a lavish use of arches in its current chancery cum residence on Tilden Street) use arched openings to establish the building's rhythm. The arch, a form common to Europe, the Middle East and Africa, makes a good bridge across the continents.

All the chanceries have tall interior spaces -- as do two recent new chanceries, the New Zealand and the Japanese. (None are proper atria. An atrium, if you're going to be correct about it, is an inner court inside a building open to the sky. Currently, people have come to call an atrium any well-lighted two-story or higher space. By this looser definition, all the chanceries have atria in the centers of the buildings.)

This sort of dramatic space seems particularly appropriate in buildings planned to trumpet the importance of nations and enhance the prestige of the visitor. The high spaces serve well as reception halls. They have the sense of the agora , or the meeting place. The same idea worked as well in medieval Britain in the great halls of the castles where the squire and his knights and minions gathered. The tall spaces, always with balconies for observers, also owe something to the theatre.

All the embassies also have great arrival courts, most with porticos so guests arriving in long dresses and limousines don't have to splash through mud. "Arriving at the chancery should be an event," said Gregory Downes, architect of the Bahrain building.

You go into the Bahrain chancery through an arched and skylit portico, set back from the arrival court. You then walk into the two-story reception hall, 40 by 50 feet, topped with a fiberglass dome, floored with an intricate tile pattern in browns to yellows, centered with a splashing fountain. The conference and dining rooms open off the reception hall. On this level as well as library, kitchen and press room. Guests can walk through the reception hall to the south terrace which extends gathering space.

The 13,000-square-foot Bahrain chancery is expected to cost only $900,000 a bargain by embassy standards. The structure is an acrylic-based stucco applied on metal lath.

Downes, who has visited in Kuwait and Saudi Arabia, was chief designer on the project, with Fred Bruck as project architect, for The Architects Collaborative of Cambridge, Mass. Louis McMillen, the principal in charge had 20 years of experience in that part of the world, including work by the firm in Bahrain, an island off the coast of Saudi Arabia, in the Persian gulf.

Downs said, "The client wanted a modest chancery and one to reflect the Arab heritage."

The site is only a half acre, and the building needs to house only 15-20 staffers. Cars are sheltered in two lath pergolas, one on side of the entry.

The Bahrain chancery is one of the few to pay any attention to energy saving. The tall trees shade the glass. And the east, south and west windows are deeply recessed.

On the second floor is the ambassador's suite, and across a bridge, the offices for the staff.

The chancery of Israel also has an especially welcoming entry court.

The Israeli 73,000-square-foot chancery is set well back from the street. It's lot, a bit better than an acre, is one of the larger sites. The large entry court leads to an arched, covered portico and a steeply angled, canopied entrance to the interior court. This roof rises four stories high, lighted from the top by the fourth story's clerestory arches. This hall will have sculpture and wall hangings from Israel to give it color and warmth. The floor will be handmade tile from Israel.

"I hope the balconies on each floor will give the feeling of a hill village," said Luis Bernado. He was the chief designer for architects Cohen & Haft, Holtz, Kerxton & Associates.

On either side of the great hall are 40-by-40-foot reception rooms, to hold 4,000 people or so. The hall adjoins a walled courtyard at the rear.

The embassy has "no marble or gold trim," said Bernardo, "only brick and glass, strong but humble materials. Israel is a powerful but not rich country, and we hoped the building would show that."

Mokhless Al-Hariri of the Georgetown Design Group is the chief designer for the Yemen chancery. Al Hariri -- a graduate of the Ecole Beaux Arts in Paris -- has visited 17 of the 21 Arar countries. His effort is the most strongly accented of all. The 18,000-square-foot building will be built of beige limestone with a strong decortive trim of black granite. The arched windows will have half moons of strained glass in several patterns, all made by Yemen workmen especially brought to do the work.

The cost is expected to be about $2.5 million to $3 million.

"I think of it as a classical building," Al-Hariri said. "It serves two major functions. Those coming to see the ambassador will come up the stately stairs over the portico, be welcomed in the interior courtyard (30 by 30 feet and 20 feet high) and ushered into the reception and meeting rooms.

"Those people who have simpler needs, consular problems or such, will walk down the steps on either side of the grand entrance and into the offices leading from the portico."

The Yemen site, according to Al-Hariri, is the most difficult of all. "It has such a tremedous drop at the back. We have tried to make a virtue of it by building terraces held by rubble stone walls."

The architect said his firm was spending as much time and effort on the interior design as the exterior. "You have to know where all the furniture is going to go, and what the graphics will be. No part of design is unimportant."

Bids have already been opened on the Yemen project and work should begin soon, with completion expected in about two years.

The Ghanaian embassy has been held up by several sudden changes of government. The building's design, patterned after a great chief's house, has been finished since 1975.

It has probably the most elaborate of all interior plans -- stages for talking drums, pedestals for sacrificial libations and an elliptical staircase built around a giant teak or mahogany tree trunk. The roof of the great court will be 35 plastic pyrmids, shaded by deciduous vines. The balconies will be a rain forest with orchids and ferns. Ghanaian woods will panel the offices. And the reception rooms will be furnished with the ornate, gilded, three-legged ceremonial stools of the country.

The exterior is to be of white Georgia marble with retaining walls planted with wisteria.

Vik Adegbite, a former Ghanaian government architect and officer, served as consultant to the firm of Leon Brown and Thomas W.D. Wright on the project.

The Kuwait chancery is the only one of the group that makes no attempt on the outside to speak with a foreign accent. It is an international style building.

Paul Vieyra was the designer for Skidmore, Owings and Merrill (Michael McCarthy, partner in charge). He admitted that the building is large (62,790 square feet) for the land. "The densities are much too great for these sites."

Each side of the rotated square form is the same.

The walls are a matt-finished stainless steel. On the lower floor great walls of slightly reflective glass form the three-story-high reception space, with a central fountain and marble floors, topped with a 15-foot square skylight. The building sits on a podium or platform of granite.

The upper level will be offices for 68 people in the cultural and military sections. The basement will house 38 cars. There is no provision here for the ambassdor -- he's expected to keep his office in the residence on Tilden Street.