Old houses seem to bring out their owners' best intentions and to offer the worst surprises for those brave enough to tackle them. Some restore, others rehabilitate, others redecorate. Such efforts have been going on for generations, but the last 10 years have seen a revival of preservation fever -- a push to restore, not just "fix up," old houses.

Some preservationists scour libraries and family histories for hints of what their original house looked like inside and out, while some generally research the period and attempt to recreate a feeling reminiscent of the house in its prime.

"There are very few really pure restorations of private homes in Washington," says Nicholas Pappas, a preservation architect with the firm of Yerkes, Pappas and Parker. But the area has a number of neighborhoods with enough architecturally significant houses to have qualified for inclusion in the National Register of Historic Places -- sections of Capitol Hill, LeDroit Park, Mount Pleasant, Georgetown, Anacostia and Old Town Alexandria. Most recently, parts of what is known today as Chinatown have been proposed as a potential Historic District.

Even in areas listed in the National Register, many efforts to achieve supposedly "pure" restorations have been colored by trends in interior design at the time of the restoration. Christine Meadows, curator at Mount Vernon, tells of a big push to restore that historic home in time for the 1932 bicentennial of Washington's birth. "In the 1930's, there was a tendency to restore rooms to what people thought they should look like by stuffing them with period furniture, rather than looking at what was really recorded as having been in the house," says Meadows. Using new research and more scientific techniques to determine the original painted finishes have led to the most recent restorations of the house. The foyer and library of the home have been "grained" by local artisan, Malcolm Robson, in the style that Washington had had installed. The library, built from 1773 to 1786, had fine pine moldings all grained to look like walnut.

Finding artisans to fill in and imitate work common to an earlier period, like graining and marbling, for example, is one of the most difficult and expensive tasks in restoration, as individual homeowners in the area have discovered.

In the case of a young Mount Pleasant couple (he is a member of the board of Don't Tear It Down, the area's local preservationist group), restoration meant camping out in their home for nearly five years before they could inhabit the front two rooms. Like many of the city's big old homes, this one had been abused as a rooming house for a number of years, and then suffered at the hands of would-be remodelers who did things to the 10-foot ceilings like applying circular stucco-like plaster patterns to the surface.

To rebuild elegant crown moldings in their 1907-08 Georgian revival colonial home, they cajoled a plasterer out of retirement to recreate the moldings from wet plaster by "drawing" out blobs of the wet stuff at the juncture of the wall and ceiling.

The restoration of this home presented an interesting set of problems. The house was built to mirror a style popular in the 18th century, but like most revivals or restorations, it has elements of the popular styles prevalent during the period in which it was built. The owners refer to it as "Georgian revival with touches of Mission," an arts-and-crafts look popular in the first two decades of the 20th century.

The decision was made to restore the house to its 1907-08 hybrid look, adding to its jumble of periods with a contemporary kitchen.

The balusters had to be returned, since so many were missing. And the wood paneling on the first-floor walls was found stuffed under a porch, awaiting the hands of a dedicated preservationist.

Another house rescued from rooming house status was almost a decade in the restoration process. Because of lack of records about the original house and a need to make the brick dwelling conform to contemporary needs, its owners (who prefer to be anonymous) say that it is at best a combination of restoration and re-creation. Most of the furniture in the 1870s house is in keeping with the period, and the moldings have been enhanced by a clever faux-acanthus leaf motif, which is actually a strip of handpainted wallpaper. At the back is an elegant latticework porch and in front some gingerbread freely drawn from pattern books of the period.

Good research and intelligent guesswork are important to any restoration job. When one is confronted with a "naked" room, however, recreating a historic look isn't necessarily as binding. There is nothing to match, no standard except one's own sense of esthetics.

There are so many good products on the market to mimic historic finishing details that, with the right research and design sense and a good set of reproduction furniture, you can virtually transform any room into a period setting. Antique-style millwork, special plaster niches, cornices and medallions can be purchased or made to order, all contributing to a thoroughly phony but somehow believable "preserved" environment. The budget-conscious can purchase fake plastic medallions and glue them to the ceiling for a small, inexpensive decorative touch around the dining room chandelier, or order fake pieces that give the look of old tin embossed ceilings.

While it is true that precise restorations do take time, research and a lot of money to produce, something less than that can be had using ingenuity and ready-made products on the market. Weaver Brothers and Union Hardware, for example, both carry a wide range of reproduction hardware, plaster work and even some molding. And, if you can't get it ready-made, there are a number of recognized specialists who can help you (see below). In short, if you don't have it to restore, you can fake it.