Help for historic districts

Despite the coming slash in historic-preservation funding by the federal government, historic districts across the United States may have a rosy future after all.

The promise of continued progress can be assured in large part, say professional preservationists, by the Economic Recovery Tax Act of 1981. The act encourages rehabilitation of income-producing properties by offering 15, 20, or 25 percent investment tax credits, depending on the age and historic significance of the building to be restored.

A 30-year-old industrial or commercial structure, for example, may be eligible for a 15 percent credit. The 25 percent credit applies to certified historic structures, and buildings be nonresidential or residential. Currently, however, projects must prove that there has been ''substantial rehabilitation;'' in other words, that expenditures exceed the larger of the taxpayer's adjusted basis in the property or $5,000 over a 24-month period.

Historic districts are groups of buildings recognized by the National Register of Historic Places as exhibiting facets of American growth and development through architecture, historical association, or social history.

Unlike the urban-renewal projects of a decade ago, historic districts are designed not only to preserve significant buildings, but to rejuvenate and often renew them by encouraging the alternative use of older structures.

Further, historic districts are not confined to deteriorating urban neighborhoods; they encompass prosperous blocks and suburban and rural towns and regions as well.

The complex objective is to enhance the old and ensure stability. The goal is to inject the kind of economic vigor that results from well-kept neighborhods, inviting sales and rental properties, and a wide variety of downtown amenities - theaters, museums, and shops - which tend to attract the public.

Typical of the increased activity within historic districts is the growing number of applications in New Jersey for tax benefits under the Economic Recovery Tax Act.

According to William Forwood, historic preservation specialist with the New Jersey Department of Environmental Protection, the same number of applications were received for review in the first six months of the current fiscal year as were submitted through all of the previous year.

The properties range from industrial complexes in rural areas that are frequently well kept to depressed urban centers.

In Jersey City's Hamilton Park and Van Vorst Historic Districts, for example, conversion of 19th-century brownstone town houses into three- or four-apartment complexes will mean the availablity of one- and two-bedroom units at rentals of City to high-priced Manhattan.

The greatest failure of the tax-incentive program is that it focuses on aid to commercial or multifamily, rental property, asserts Cynthia Howard, an architect and preservation planner, who heads her own firm in Cambridge, Mass.

''The key to providing stability and survival to older urban neighborhoods,'' she says, ''is this population base that has an investment in a revitalization of the housing stock and in the community as a whole.''

Miss Howard also points with regret to the discontinuation of federal funds to the states, which will assume responsibility for monitoring the tax act.

In Paterson, N.J., Nancy Gay sees the imminent move of that city's museum into the 19th-century Rogers Locomotive Works building as a necessary prod to activity within the entire historic district. Mrs. Gay is executive director of the 119-acre Great Falls National Historic District, which was once the hub of the world's silk industry in an area founded by Alexander Hamilton.

''With the current lack of federal funding and the absence of private homes within the historic district, there must be larger commitment on the part of the city administration and the people of Paterson,'' says Mrs. Gay. She regards the presence of the museum in the historic district as the catalyst that will ''provide the greater commitment of the administration and other avenues for the community at large to participate.''

Cultural institutions have introduced the spark of success to other historic districts.

The waterfront at Penn's Landing in Philadelphia could not be effectively marketed until a commercial museum occupied an unused new building. Developer James Rouse did not come into Baltimore's Harbour Place until a science center and aquarium were located on either side of the harbor.

''Those two institutions, on their own, will bring a million people to Harbour Place this year,'' Mrs. Gay predicts.

''No matter where you look at urban historic rehabilitation, the presence of a cultural institution offers a solid base,'' she adds.

Another ingredient necessary to the success of the historic district, according to Miss Howard, is ''economic health at the base of the community.''

Home ownership, where it is at all feasible, stimulating pride and self-interest, is a major ingredient in ensuring a community's economic health, Miss Howard says.

In Plainfield, N.J., the residential Hillside Avenue and Van Wyck Brooks Historic Districts, which were developed from 1870 to 1925 as enclaves for the rich, status as a historic district has ''increased pride of ownership,'' comments John Grady, board member and former director of Plainfield Heritage, a nonprofit organization that focuses on local preservation issues.

''It also has resulted in the repainting of the large homes and greater resident involvement in the efforts to enhance and preserve their neighborhoods, '' Mr. Grady adds. As further evidence of their pride, five and six tours a year are conducted through the Van Wyck Brooks Historic District by adult schools and local museums.

Residents have erected street signs that label the area as a historic district, and owners have posted small plaques on their homes.

''With the historic importance of their homes emphasized by Plainfield Heritage, the latent interest of the residents has been awakened,'' Mr. Grady says.