Most of the 222 Washington area lending institutions raised their home mortgage loan rates an average of nearly one percentage point this week, to an average of 16.3 percent, according to a survey.

Seventy-three percent of the institutions raised their rates, from an average last week of 15.4 percent with a 20 percent down payment.

But 40 percent of the institutions surveyed have stopped making mortgage loans altogether; another 12 percent are limiting new loans to previous customers.

Bank officials, however, say they aren't getting many takers anyway. While the rising rates have inspired consumers and lenders to search for "creative" methods of financing, they have also forced many prospective home buyers out of the market because their mortgage payments would be too high.

"I don't think it really hit home until this week," said Cheryl Insko, vice president for mortgage loans for Arlington-Fairfax Savings and Loan, which increased its rate to 17 percent this week.

"When people found out that the largest banks were raising their rates to discourage loans, they realized that they just couldn't get the 13 percent loans that they could a few months ago. It hit home that they couldn't afford it and they're deciding not to buy," said Insko.

The highest rate offered in the area yesterday, according to the survey, was 18 percent by Suburban Savings and Loan of Annandale, up from its 14 3/4 percent offering last week.

A spokeswoman at Suburban Savings and Loan said that in past years, "March is a big month for us. Come spring, people start looking seriously for new homes. . . . At this time of the year last year, when our rates were 10 1/4 percent, we were pretty busy. . . . We were getting 17 or 18 applications a week. Now we're getting very few.'

"The banks are telling me they're writing very few loans," said Victor J. Peeke of Interest Data Reports, a private firm that did the survey. "It has slackened down pretty bad. People who work in mortgage companies who are on commission say they haven't written a loan for the last couple of weeks. It's bad."

The higher interest rates mean that a person who took a mortgage this week on $80,000 at 16.3 percent for 30 years would pay about $1,092 per month for principal and interest, compared with a payment of about $1,038 at 15.3 percent on a mortgage taken last week. That same $80,000 mortgage would have cost about $702 per month in June 1979, when interest rates averaged 10 percent in the area.

But many banks say they are having difficulty offering loans.

"Heavy savings withdrawals have cut back our ability to make loans," said a spokesman for Independent Federal Savings and Loan. "We aren't making loans anymore. . . . No one is satisfied with the 5 1/2 percent interest they get in passbook savings accounts. They are going to things like money market funds, which pay in the 10 to 13 percent bracket, to try and keep up with inflation.

"It [the economic situation] is worrisome," the spokesman said. "We keep hoping it's going to change . . ."

The spokeswoman for Suburban Savings and Loan said its 18 percent rate was set to discourage customers from seeking loans. "We don't have the money to lend," she said. "The money costs to us are so great and the income from savings accounts is not that great, so we have to slow down. It just doesn't pay."

With interest rates soaring, lending officials say, consumers and institutions are looking for new, "creative methods of financing."

The Suburban Savings and Loan spokeswoman said her institution was working with new home builders to "help them move their inventories."

Some builders, she said, are offering customers a lower interest rate -- around 11 1/2 to 11 7/8 percent -- on their mortgages for the first two or three years. The builders pay the difference in the bank's rate and their offered rate for that period, after which the buyer can either refinance his loan at a lower rate or assume the full mortgage payments.

Other banks are offering such option directly to the new home buyer, according to another savings and loan official.

But many prospective new home buyers are simply giving up on the idea of buying a new home.

A lot of "people are looking at older homes that have a mortgage they can assume." said Insko of Arlington-Fairfax Savings and Loan."And there is a lot of refinancing going on, too. People who in good times would have bought a new four-bedroom home are staying put and building an extra bedroom on the house."

"In the past, people were just going out and buying houses," said Walter Preston, a financial expert who prepares a similar survey. "They would say, 'I want that house' and then they would buy it. Now, they're looking more closely and thinking that maybe they can't afford it."