Restoration has been completed on a 19th-century home encompassing a log-and-mortar cabin built in 1840. The owners are selling the Potomac house with antique furnishings for $398,000.

The two-story home, called Garrett House, also includes two Victorian-style additions built at the turn of the century and a new two-car garage.

Garrett House stands on 2.2 acres, about one mile east of River Road at 10500 Falls Rd. Owners Carol T. Taylor, Paul Arnold and David Cahoon spent two years rehabilitating the seven-room structure, which is listed on the Maryland Historic Site Inventory as the Ashton Garrett House. They purchased the home in 1979 for $130,000 and spent "substantially more than the purchase price" on the restoration, Arnold said.

Taylor took time off from her job as a real estate broker with Mount Vernon Bogley, Inc. of Potomac to work on the house; Arnold, a part-time real estate developer, helped on weekends and evenings after returning from full-time work as a manager in the Office of Personnel Management; Cahoon moved into the house, eating and sleeping there for 18 months while work progressed. Assorted subcontractors, friends and "a lot of college kids" put time in, as well, Taylor said.

"Since I was living here, it became a part of my life," said Cahoon, a 24-year-old philosophy student-turned carpenter. Taylor and Arnold made most of the esthetic and financial decisions, he said last week when the house first was shown, but the project was "very much a partnership."

In addition to extensive work done on electrical wiring and plumbing, a new heating and air-conditioning system was required, and the floor of the cabin was lowered to make it compatible with the rest of the house, Taylor said. The roof leaked badly, she added, requiring 3,000 pounds of tin shingles to repair the Victorian-era sections; the original cabin section was refinished with cedar shakes.

Although the house was partially insulated, fiberglas batting and insulation boards were installed to meet R-31 standards in the ceilings and R-19 in the walls, and the building was resided. The garage--which includes a spiral stairway to a sky-lighted loft area--was also insulated.

A 15-by-21-foot dining room with southern exposure occupies the first floor of the original cabin, opening onto a small, brick patio rimmed with English boxwood. The room steps up to a modern kitchen--converted from a closed porch that was added in the 1950s--and stairs lead down to a tiny root-and-wine cellar with a flagstone floor.

The lower level of the Victorian section is comprised of a living room and a den with adjacent bathroom. Both rooms include wood-burning fireplaces faced with Italian marble. A staircase leads up from a center hallway to three bedrooms, two more baths and a laundry room. The largest bedroom fills the 21-foot-long upper room of the cabin; its modern bathroom includes a Jacuzzi whirlpool tub.

The selection of antique furniture and the interior design were handled mainly by Jean Paul DeBoeck, director of The Unicorn and The Lion in Vienna. DeBoeck said he designed the rooms to sell the house, not to make them look lived in; nevertheless, the sparely furnished rooms are handsome sights.

The majority of the furnishings were obtained by DeBoeck from shops in the metropolitan area. Most of the pieces were made in American from 1840 to 1890, though some are European or from an earlier period. A few antiques are on loan from friends and are not included in the sale price, Taylor said, noting that prospective home-buyers may elect to exclude some or all of the items from the purchase.

Garrett House will be listed with P. D. Lebling Realty, Inc., in Potomac starting next Thursday.