In the wake of the announcement by the Washington Gas Light Co. that it plans to re-enter the residential market after a five-year hiatus one might have expected some huzzahs from builders who were formerly big installers of gas appliances.

Three major builders took the news with some surprise - but calmly. Generally, they said, they were delighted that gas heat would be available for 10,600 new or rehabilitated houses within the next two years. But they pointed out that area home builders have had to switch to the use of electric energy with heat pumps or to oil heat in the interim.

It was also noted that both electric heat and oil heat have become far more competitive with gas in recent years. One builder said that new availability of gas for residential heating probably presages higher rates for the fuel. All three forms of residential heating are now generally competitive, it was agreed, so it's becoming a matter of individual preferance of home buyers.

At this point it appears that Washington Gas Light Co. will have to fight to regain its place in the area market after being out of it since 1972. And to regain gas will have to prove itself again in terms of economical use.

Over in Berkeley Spring, W. Va., broker Connie Perry sat in the Strosnider Realty office on a rainy Saturday morning and enjoyed talking real estate with visitors from Washington. Perry said business has been so good that she made commissions on $1.1 million in farm and residential property sales last year. "Prices have really taken off since a lot of retirement and recreation-minded "Washington area people have come out this way looking for bargains," she said with a meaningful smile.

Some years ago the Artery Organization devised a plan to encourage tenants in its rental properties to buy its sale houses. Basically, the offer was that anyone buying an Artert-built house would get a bonus equal to 10 per cent of the rent paid. In less than 10 years, nearly 50 tenants have taken advantage of the offer, according to Henry H. Goldberg, president of Artery.

The most striking example of the rent rebate is happening now. The Donald Manganello family, which has lived in Georgian Woods since 1968, is buying a new Coventry town house in the Crofton area. The Manganellos are eligible for a check for $2,613.07 toward their $46,500, Artery-built new house on which they plan to settle Oct. 31. Who said that all those rental receipts are valueless?

Lewis M. Letson now is on board at Rossmoor, Md., as executive vice president and general manager of Rossmoor Constuction Corp. He takes over the major executive responsibility from John Dodds, who has left to join Michael Rose and the KBB Co., which has increased its building pace in Maryland. Letson, who has been at Rossmoor as project manager, assumes the total responsibility for the new corporation, formerly a subsidiary of Rossmoor Corp. Elm Weingarden, senior vice president of Rossmoor Corp., plans to select a new marketing executive for the adult community in the Norbeck area and make monthly visits from the West Coast to "make certain that construction is something in which both Ross Cortesi and I can take pride."

Appraiser Alfred W. Jarchow, who reports monthly on Montgomery County resales, notes that the median price of existin homes in his August study was $64.500 - $2.500 more than in July. But he adds: "The median bounces up and down from month to month due to variations in the mix of properties, showing how useless this figure is for measuring price movements." He added that the August sales volume was less than July's but 13 per cent above August, 1976. Also, August sales were equal to about one-fifth of the active listings of existing homes.

When the University of Michigan football team is in action, players Russell and Mike Davis of Woodbridge have a rooting section within the varied offices of Better Homes Realty, Inc., in Northern Virginia. The Davis brothers worked for the firm last summer as part of a program to provide part-time jobs for area young persons going to college. So far this year, Michigan has been doing well in football and Russell Davis has attained national stature as a running back and blocker.