A new world beckons Howard University's School of Architecture-the Third World.

The question is only whether the somewhat lethargic university can rise to the challenge.

Since the Iranian revolution, U.S. architects, engineers and city planners-A/E firms, the jargon calls them-are returning from the Mideast and Africa almost as fast as they went there a few years ago chasing petro-dollars.

Most are returning empyt-handed and disillusioned, griping about broken promises and strange business practices. No one will give any details for fear of angering clients who might, just might, still come through.

Tough luck for the eager Americans. But it is fortunate, I think, for the people in the developing countries that Americans are not building all the skyscrapers, housing projects and mega-institutions for them that they had hoped to build.

Not that there isn't any need for building. There is abundant work for good architects, engineers and planners.

The developing countries are urbanizing at a frightening rate. Just as in the industrial countries several decades ago, farmers are leaving the land for city jobs and services. The belts of slums and misery around their cities are growing much faster than their fast growing populations.

Efforts to improve rural productivity-and thus ameliorate rural poverty-usually reduces the need for rural labor and thus further accelerates urban growth.

So do the highways and railroads needed to stave off hunger and disease ease. Improved transportation moves not only food, goods and services, but also still more urban immigrants who need still more housing, schools, clinics, employment centers, sewers, water mains, everything.

American architects, engineers and planners do not lack the competence and-in most cases-understanding and idealism to design what is needed. On the whole, they do better than the Europeans who tend to perpetuate a colonial approach in what used to be their colonies.

But there is a fundamental difference between building design in America and building design in the developing countries. In America, building material is cheap and labor is expensive. In the developing countries, conventional building materials are expensive and labor is cheap.

Our architecture, furthermore, is European. We have ignored the Asian, Mideast and African experience.

The training, the entire mentality which stems from this fundamental difference, is almost impossible to overcome. An MIT-trained designer can, of course, grasp that he has to switch gears and learn to design a building that uses indigenous materials and a lot of workers. He may even learn how to do it.

But, as Glean Chase, the new chairman of the Howard University department of architecture points out, it is almost impossible for an outsider to organize and manage a building process that involves large numbers of unskilled and semi-skilled people. But if they are not involved, if the construction of the housing, schools clinics, employment centeres, sewers, and water mains is not labor intensive, the investment does not pay. At least it does not pay the way it should.

Another problem is that the powers that be in the Third World still associate economic improvement with Western, international-style architecture-no matter how expensive, inappropriate and inefficient a Chicago-style glass-and-concrete tower might be in Nairobi.

But a Kenya architect will have an easier time persuading fellow Kenyans of this than an American architect. And a Kenya architect will have an easier time evolving a more appropriate architecture out of a combination of modern needs and local tradition.

All this points to the need for the Third World to train its own designers and technicians. Universities with architecture schools and polytechnic institutes are proliferating in the developing countries.

Yet many Mid-easterners, African, Latin Americans and West Indians still want to study in this country. They admire American know-how. We must encourage this. We should be proud that roughly half of Howard University's 260 architecture students come from developing countries and intend to practice there.

Under the deanship of Walter B. Lewis, Glean Chase and most of the faculty hope to make their architectural education more relevant to these foreign students than it is now. Chase, who was born and practiced architecture in Trinidad, studied in Germany and Israel and taught at Pratt and MIT, seems well-equipped for the task.

Chase hopes, for instance, to launch courses in tropical architecture. He hopes to help his foreign students (as well as black Americans who may want to work in developing countries) by collaborating more closely with other architecture schools in this area as well as the U.N., federal foreign aid agenceis, the World Bank and International Monetary Fund.

"There is no reason," Chase says, "why Howard should not embark on extension programs and research in building technology and planning in the Third World."

What Howard should probably be aiming for is something like a research and training Institute for an Appropriate Third World Architecture.

It would seem to be in the national interest. CAPTION: Picture, From left, Grazyna ciupinski, Akin Adejimi, Karen Carr and Glean Chase; by Harry Natchayan