Newington Forest, a 734-acre tract in the Springfield area of Fairfax County, is being developed by subsidiary of Ryan Homes and Stephen G. Yeonas. Ryan has builts model on the site, which has also attracted the National Corp. for Housing Partnerships and the Timber Glen Limited Partnership of Bruce Magazine and Lawrence Press. Zoning will permit a mix of 1, 900 dwellings, most of which will be single-family homes and town houses. Overall density will be 26 houses per acre, according to Yeonas. The site is on Pohick Road, about three miles from the Newington interchange on Route I-395.

Two Montgomery County legislators plan to introduce a bill in the Maryland General Assembly that would require builders and developers to hold deposits from purchasers of condominiums in escrow accounts until the units are finished. Dels. Lucille Maurer and Donald B. Robertson said they are proposing the law to give condominium purchasers the same protection now available for buyers of houses. New or converted condo units accounted for 27 per cent of all new housing purchased in Montgomery County in 1977.

Long & Foster, a real estate firm that helps home builders sell their houses and also handles a large volume of resales in the area, has projected today's housing prices over the next 10 years on the basis of a 6.3 per cent increase each year. The house that you buy for $50,000 today is expected to be cost $67,862 in 1962 and $92,107 in 1982. If you pay $80,000 now, that house is expected to appreciate to $108,582 in 1982 and to $147,376 by 1987. Actually, those figures, based on the Consumer Price Index of the nation, are somewhat conservative. Housing prices here tended to zoom ahead of the national pace. But even more ressuring to the prospective buyer is the fact that downturns in the economy hit the housing market here with a less devastating effect than experienced in many other areas.

Census Bureau statistics show that the median-size U.S. dwelling totaled 1,405 square feet in 1972 and rose to 1,560 square feet in 1974. However, the 1975 housing downturn and the builder fling with "affordable, non-frill" houses resulted in a median decline to 1,535 square feet in 1975. It bounded up to 1,590 feet in 1976 and probably will show another jump in 1977. Generally, a house with 1,600 square feet has three bedrooms, one or two baths, plus a kitchen and dining and living rooms. All of those rooms are what would be considered moderate size in the conventional, 20-year-old, two-story colonial now selling for about $60,000 in this area.

Friends of William L. Slayton are delighted that teh former executive vice president of the American Institute of Architects has made a new career connection with the State Department. Slayton, who came to Washington as a Zechendorf executive involved with the early private development of Southwest, later headed the urgan renewal desk in the Kennedy administration's unofficial housing cabinet.