Washington home buyers make more money than buyers in other large cities, but they pay more of their income for housing.

They are older, have smaller families, live in newer homes and tend more to condominiums than in other cities, as well.

The median price of a house here last year was $99,000, and the median down payment was $23,901.

These are some of the conclusions that emerge from a U.S. League of Savings Association profile of the Washington-area home buyer in 1981, included in the league's new study of homeownership.

The profile showed that the Washington buyer has a median age of 36, compared with 33 for all large cities, and that 63.2 percent live in households with only one or two people, compared with 59.1 percent nationwide.

Median household income of buyers here was $48,003, compared with $40,997 in all large cities. But 54.6 percent here had to pay more than 25 percent of that income for housing, compared with the 49 percent for all large cities. Median monthly housing expenses here were $1,054.

Of the Washington-area homes bought last year, 42.3 percent were new, compared with 25 percent in other large cities. But the space in them was about the same--a median of 1,446 square feet here, compared with 1,466 in all large cities.

Condominiums constituted 38.6 percent of the market here last year, compared with 23.2 percent in all cities.

The local median price of $99,000 compared with $78,000 in all cities. Of those buying, 71.1 percent made down payments of at least 20 percent.

In 1981, only 12.7 percent of the buyers in Washington were purchasing their first home.

The league study said that without changes in national policies, including more incentives for people to save, it would become more difficult in future years for first-time buyers to get into the housing market.

The league also noted the dominance nationwide of new financing techniques. In 1981, adjustable-rate mortgages accounted for just slightly more than half of all the home loans written by savings and loans nationwide, while conventional fixed-rate mortgages made up only 27.3 percent of the market.