The house needed a new roof, the back porch was rotting and chunks of plaster were on the floor.

But the price was only $17,000-and a family with imagination could fix it up. A few coats of varnish on the hardwood floors, new gutters and a new sink in the kitchen would give it character.

More and more families these days are going this route to beat the rising cost of housing. They are picking up hammers, scrapers and brushes and investing their money and time in rehabilitating old homes.

Russ Morash, a Boston TV producer, had an idea to help these do-it yourself remodelers, who spend nearly $20 billion a year on their houses.

Morash bought the shabby $17,000 house at 6 Percival St. in the Dorchester section of Boston and is filming the whole remodeling process for public-broadcasting's WGBH-TV in a series entitled, "This Old House."

The Boston station has no plans at the moment to syndicate the program, but Morash is interested.

The program follows each step-from the initial inspection to decide what is or isn't worth fixing to the final coat of paint. The host, Boston builder-designer Bob Vila, will detail the costs, problems and secrets of renovation as the work progresses. Do-it-yourselfers can watch actual sanding, plastering, electrical work, painting, caulking, roofing and landscaping.

The work will be interspersed with discussions by experts on structual problems, energy efficiency, property values and other concerns arising from house renovation.

Morash, an executive producer at WGBH, counts Julia Child's first cooking series and "Crockett's Victory Garden" among his successful past productions.

The idea for a "how to" house-renovation program came to Morash several years ago while rebuilding his own 1851 farmhouse near Boston. It remained an idea, however, until a recent poll taken by WGBH showed a strong demand for anti-inflation, economic self-help programming. One of the major community concerns was the rising cost of housing.

In searching the Boston area for a suitable site for the program, Morashd discovered that comparable houses cost three times as much in the suburbs as they do in the city.

The clapboard house he finally selected for "This Old House" sits on Dorchester's Meeting Housing Hill, an aging residential neighborhood in Boston. Built in 1861, according to the best estimates of the WGBH staff, the house is in "poor, but not excessively poor" condition.

The project has earned WGBH a congratulatory resolution form the Boston City Council for helping to "save the architectural beauty of Boston neighborhoods." Local real-estate brokers say that, since the project began, property values on Meeting House Hill already are going up.

As "This Old House" progresses, a book will be developed along with the series. The book will delve deeper into detail than is possible in the television program. CAPTION: Picture, "all it needs is a little work," says TV producer Russ Morash, who is filming series on fixing old houses. Christian Science Monitor