The rehabilitation movement has spread to the two more pieces of Washington real estate - the 1200 block of Linden Place NE and the luxury apartment building at 2029 Connecticut ave. NW.

There are 44 rather small, two-story rowhouses on Linden Place, which is located near the H Street corridor of Northeast.

"When I came here some months back it was really rough," said John B. (Jack) Sharkey, the redeveloper. "I bought five abandoned houses in 1974 and moved into one of them with a sleeping bag and a shotgun to protect myself." But in three years, according to the 35-year-old Sharkey, the block has turned into a cohesive neighborhood, where a dozen or more of the original black owners still live in their own houses and where other houses have been purchased and fixed up and sold.

"Now the population is about 50-50 black and white and redone houses are selling in the $70s." he said. "I paid $3,200 to $5,300 for the first five abandoned dwellings I bought and fixed up."

Sharkey now is redoing other houses on the block and so are rehabilitators Robert B. Noland, Michael Planka, Louis James, Stephen Kopsidas and Kathleen Kaupp, Ronald and Deborah Calloway, who were Sharkey tenants for a year, have bought and are redoing their Linden Place house while living in it.

Because the 16-foot-wide rowhouses have only about 1,300 square feet of living space and no basements, some of the going prices today average about $60 a square foot, Sharkey said.

Meanwhile, over in the long-fashionable Kalorania area, a crew from Excolene Corp. has been taking off the dirt and grime that has accumulated on the ornate marble and travertine exterior of 2029 Connecticut since 1916. Built with a Renaissance flair by R. Bates Warren (as in Kennedy-Warren), the building was bought by developer Conrad Cafritz earlier this year. Cafritz plans to convert the 25 larger-than-life rental apartments to condominium ownership.

The realty firm headed by G. V. (Mike) Brenneman is handling the sales at 2029, where the redeveloper is putting in new heating and electrical systems and doing some moderate modernizing - while trying to maintain the quiet ambience and spacious-gracious living that has marked the style of the financially stable, mostly mature tenants these many years.

The ornate building was considered the utmost in fashionable living when it was opeded prior to World War I. About 10 years later, it acquired a new neighbor across the street called 2101 Connecticut, which was recently was converted to co-operative ownership.

Located as they are on the curve approaching Taft Bridge, those Connecticut Avenue addresses have been heavyweights ever since they opened. Some of the foyers in those apartments are larger than the living or family rooms of some of the $100,000-plus new houses now being built in suburbia.

Not unlike the slightly younger 2101, the seven-story 2029 had begun to show its age. But some of the tenants have been there for some years and thus tend to regard their apartments, some of which boast 5,400 square feet of living space, as "home forever."

So far, about half of the tenants have bought the apartments they live in, even though it will cost them a pretty dollar - up to $240,000 for the biggest units - to continue living there. Despite the fact that condominium fees and taxes will be heavy too, only seven of the big apartments are unsold.

Excolene Corp., which is doing the $60,000 chemical cleaning and water-proofing at 2029 currently, is one of several firms that have helped clean up the faces of downtown office buildings here in recent years. The highly artistic facade at 2029, which gets its share of exhaust from heavily traveled Connecticut Avenue, soon will be much more visible.

Richard M. Shamp, president of Excolene, said that his crews have been applying chemicals to downtown office building facades to remove accumulated muck. They follow this up with high-pressure water to remove the residue. Finally, in most cases, cracks are filled and other repairs made before a waterproofing liquid is applied to protect the cleaned surfaces.