A new house is like a new car: the investment reflects the buyer's self-image, and a scratch on the paint job, let alone a leaky roof, can drive him to distraction.

As vexing as problems in workmanship and materials may be, consumerists and builders say that warranty protection can limit disgruntlement and avert financial disaster.

"We usually don't get into arguments with people," says Ray F. Smith, president of Sequoia Building Corporation in Fairfax County. "That doesn't mean that nothing is wrong; we just have a system for going about working on a new home just like a good car dealer."

Smith has an independent warranty program, but he is an exception. According to Bob Johnson, executive vice president of the Northern Virginia Home Builders Association, about 250 builders accounting for 85 percent of the new homes in his jurisdiction participate in the Home Owners Warranty (HOW) Corp.'s program--and more building goes on in Northern Virginia than in the District and Maryland suburbs combined, he says.

HOW, established as a subsidiary of the National Association of Home Builders in 1973, now is an independent company that operates nationwide. It accepts applications from builders and screens them before accepting them into the program. It assigns members a rate per $1,000 of a home's purchase price, from about $2.45 to $3.75, that can change if the builder's subsequent claims record is good or bad.

The buyer gets protection against certain structural defects for 10 years, but the distinction between what is structural and what is not can get pretty fine. Roof shingles and sheathing are not covered, for example, but roof framing systems are.

For the first two years, the builder is responsible for specific repairs made necessary by defects in materials or workmanship. If the builder fails to comply with the standards, "he's kicked out of the program and HOW goes after him," Johnson says; if the builder goes out of business in those first two years, HOW maintains the coverage.

"Unfortunately, it's expected that something will go wrong" with a new house, says Johnson, whose association is a local HOW franchisee. But he advises seeking remedies through an association like his before going to the county. (The Magnusson-Moss Warranty Act, in fact, forbids a buyer to go to court before going through HOW's procedures, although there are exceptions to this.)

Dorothy Verrilli, HOW's administrator for seven Maryland counties, says it can take as little as a call from HOW to the builder to get a complaint smoothed out, just because "generally, buyers are pretty frustrated because nobody's bothered to call them" from the builder's service department.

HOW, as Johnson and other officials point out, has precise time frames for notification and resolution of a complaint. First, Johnson says, his association might try to apply peer pressure to get a builder to correct a problem.

If the complaint is handled through HOW, the builder must acknowledge it within a certain time and then start work "with a bona fide intent to correct" the problem within 40 days, Johnson says. If the builder disputes the need for repairs, certified, independent arbitration is the next step. Should the buyer lose, a second round is available.

If the buyer loses again, "the insurance company considers the case closed," Johnson says, and court action is the next remedy available.

The main thing from the start is to be aware of what is covered, what is not and to what those items of concern are that merit protection. Is the builder a HOW participant? If not, does the builder have an independent warranty program? It is important to get promises in writing and, if things go wrong, to keep a written record of dealings with the builder--"especially for the first two years," says HOW's Verrilli.

Gloria Kornasiewicz, chief of the investigations division at Fairfax County's office of consumer affairs, notes, "This whole area is one of our major complaint categories--second to automotive complaints." She adds that solving such problems takes longer than many other kinds of complaints because of the "size of the product and the number of things that can go wrong."

In Montgomery County, however, Barbara Gregg of the consumer affairs department says that "recently, with the slowing down in building new-home complaints have been going down and the trend is an increase in home improvements."

In the District, new-home construction is so slight a part of the housing industry and HOW participation so limited, with about a dozen builders, that HOW handles complaints through a regional office in Haverford, Pa. In 1981, HOW started a rehabilitation coverage program, but Vincent Chiarello, regional director, says that interest rates discouraged people from tearing out the insides of abandoned buildings and restoring them.

But now, he says, HOW is introducing coverage for remodeling, so long as it is a "multitrade" effort. "We're at the stage where we're accepting contractors' applications," he says, and they can be sent to him at the HOW Regional Office, 600 Harverford Rd., Haverford, Pa. 19041.