HOUSING POLICY in the United States until very recently has been a great success for most people. The average person now enjoys a standard of convenience and sanitation unknown to our forebears and to most of the world. Almost all of the really atrocious housing--the kind with no heat or running water that only a generation ago housed most of the poor--has been torn down. Its former occupants now occupy the dwellings vacated by those who have moved on to fill the expanding supply of better housing.

Direct housing policy had only a minor part in this success story. The featured players have been rising incomes and tax policies that, in a variety of ways, favor housing investment. Billions spent on public housing and other low-income housing subsidies have left millions of the poor still living in overcrowded and otherwise substandard conditions. With newly constructed public units now costing far more than any low-income family could begin to pay, a presidential advisory commission has concluded that it is time to junk federal housing construction programs entirely. The commission, appointed by President Reagan last June, now recommends that some of the released money be used to fund housing vouchers with which the poor could seek better housing in the regular market.

Housing vouchers fit in nicely with the administration's free-market philosophy. Vouchers also put most of their money in the hands of the poor-- rather than the builders--and spreading money among all the needy seems fairer than rewarding a relative few with nice new housing and giving the rest nothing. Vouchers would probably have to be distributed on an entitlement basis--you can't have waiting lines for money the way you can for housing units. Researchers estimate, however, that of the 6 million families likely to participate, over half are already getting housing aid.

The principal shortcoming of housing vouchers is that they don't do much to improve housing. Many of the neediest families--particularly large families --can't qualify for benefits because they can't find housing that meets the required minimum standards. Because the allowances are necessarily small, most of the people who do qualify simply use them to cover part of their present housing costs. The assurance of steadier rent payments may convince some landlords to make small repairs, but most of the voucher money ends up, in effect, being spent for things other than housing.

Whatever else the housing voucher may have going for it, timing is not on its side. Congress, now struggling to control existing entitlements, is not likely to enact another. There is also a Catch- 22 quality about sending the poor out to seek better shelter in a housing market that, thanks to high interest rates, is near collapse. Even with high rates of construction, "trickle-down" of existing stock won't serve all the poor. In the present economic climate, the prospects are dim indeed. The major present threats to improved housing for the poor are not so much budget shortages as the slowdown in key sectors of the economy and the apparent inability of a constrained government to do anything about it.