A report on America's housing needs issued Tuesday by the MIT-Harvard Joint Center for Urban Studies indicates that one out of every five American households has inadequate housing.

The report, compiled from 1970 Census figures, shows that 13.1 million families live in physically substandard housing units, are overcrowded, or pay an excessively high percentage of their incomes for rent.

The federal Department of Housing and Urban Development provided half of the $170,000 cost of the study. Researchers at the Joint Center expect that the report will have an effect on federal housing policy for the next decade.

David L. Birch '59, principal investigator for the study, said yesterday he hopes the report will demonstrate to federal housing experts the need for a mix of programs--more construction, housing subsidies, rent control, mortgage loans--in order to deal effectively with the range of housing problems across the U.S.

Varied Approaches

"New Haven and Houston are, naturally, very different problems," he said. "President Nixon has accepted the notion of a mix of programs at the national level. We're trying to show that there is also a need of varied approaches within each metropolitan area as well."

The research group chose the criteria for inadequate housing that led to a conservative national figure, Birch said. Physically substandard housing was judged only on the basis of adequate heating and plumbing and discounted such items as lighting, ventilation, and a unit's sanitary condition.

The report's figures are drawn from households with incomes under $10,000 a year. For this group, an overcrowded unit is one with at least three persons and at least 1.5 persons per room.

Households were considered to have an excessive rent burden if more than two persons live in the unit with the head under age 65 and pay more than 25 per cent of their income for rent.

The major problem in metropolitan Boston, a statistical area including Cambridge, is excessive rents, the report said. Of the nearly 86,000 households in the area, 16.2 per cent have a high rent burden, while 9.7 per cent live in physically inadequate units and 1.0 per cent are overcrowded.