Potential home-buyers in the Washington area will be deluged in the next month with two unprecedented ad campaigns--one directed at Northern Virginia--designed to get them out looking at homes again.

As the traditional spring home-buying season begins, members of the local housing industry are planning a joint $450,000 investment in television ads, betting that the public will buy if it considers the deals available.

A coalition of the local homebuilders' associations, Realtor boards and lenders is to begin a $300,000 ad blitz Thursday on local television stations, featuring actual buyers. In these ads, individuals will tell their stories of why and how they bought, despite today's high interest rates that have kept so many out of the market.

Separately, the Northern Virginia Board of Realtors is starting its own $150,000 TV ad campaign, possibly the largest advertising effort ever undertaken by one local board.

These ads will feature an actress portraying a local Realtor, describing three different types of concessions now being offered by home sellers: builders "buying down" interest rates below market levels, a $10,000 price cut and a home offered with no down payment required. The Northern Virginia group also is contributing $50,000 to the coalition effort, a spokesman said.

The message from both campaigns will be basically the same: you can afford to buy.

The campaigns are largely an effort to overcome what real estate agents and builders say is a negative psychology, fed by news of high interest rates and slow home sales, that they believe keep potential homebuyers from even looking.

High interest rates make monthly mortgage payments soar. For example, on a $100,000 home, the monthly payment is $877 at 10 percent interest rates of a few years ago but $1,425 at a 16 percent rate.

But real estate agents and builders point out that many sellers now are offering a variety of concessions, including financing plans designed to ease buyers over what they hope is a temporary period of high rates. High interest rates themselves now are less of the problem than "consumer uncertainty" about them, argues Robert L. Mitchell, president of the Suburban Maryland Home Builders Association.

Funding the campaign has been partly a matter of convincing industry members to contribute at a time when many can least afford it. Mitchell's March newsletter to association members said that $200,000 of the $300,000 had been raised but that individual builders needed to contribute a minimum of $1,000 each.

"I told you in January that we would all have to contribute to the effort to replace consumer uncertainty with consumer confidence. Some of you heard me; others apparently did not," he admonished the members. "For those who did not, get your thumb out of your ear, pay attention and act now."