A recent assemblage of buildings and land near Connecticut Avenue and L Street NW - for what is expected to be a major redevelopment - included four small, adjacent tracts that were sold to developers T. N. Lerner and Albert (Sonny) Abramson through veteran commercial broker Sol Wolberg, a vice president of Shannon & Luchs. It took Wolberg nearly 12 months to complete the negotiation with four separate owners to fill out the site around the LaSalle building at that intersection. The land asembled and sold through Wolberg totaled 13,000 square feet and the sale price was about $2.2 million. The Lerner-Abramson duo may soon be making plans to raze the properties on the southwest corner of Connecticut and L - and may acquire even more property on L Street for the eventual construction of a major hotel and urban shopping plaza. Wolberg, 87, has long specialized in downtown real estate assemblages and sales.

Another downtown-midtown corner has also been the subject of some recent redevelopment interest. The YWVA is reported to be looking for a new site downtown and officials are getting out the word that the Y's present location on the northeast corner of Connecticut and K NW would be available for redevelopment. Although the site is only 18,000 square feet, there are reports of interest at prices higher than the estimated $250 a square foot put on the LaSalle property, which is on a land lease. YWCA officials want to stay in the downtown. The YMCA, meanwhile, is building a new structure at 17th Street and Rhode Island Avenue NW. The men's organization was at 1742 H St. NW for many years.

Newly open for sales in Old Town Alexandria is the Princess Street project, where developer Lawrence N. Brandt is building 46 town and three-story town houses in a block surrounding a small pool and a tennis court. Prices average about $70 a square foot and the two-bedroom-den units have about 2,000 square feet of living area. VVKR did the federalist architecture and Brandt is the builder . . . A year ago, Brandt opened sales at the Beekman Place town house on 16th Street at Meridian Hill. Now the sales total is 150, ahead of the expected pace. Since the opening, prices for the two-bedroom units have been increased from the low $60,000s to nearly $80,000. Brandt has plans to build a high-rise on 15 acres of the Glover tract, near the Foxhall in the Massachusetts-New Mexico avenues area.

Security is a matter of concern to owners and tenants in urban areas. A new resident-owner of a condo apartment in Skyline Plaza North recently complained to the Charles E. Smith companies, which handle development and management, about an unauthorized entry. "It was an honest but regrettable mistake by a salesperson," responded Sidney Glassman, vice president for property management of the Smith firm. His investigation disclosed that a sales person wanted to show an unoccupied unit in the building to a prospective buyer but missed the destination by one floor. He also explained that sales agents have master keys until most of the units in building are sold. Then individual keys are used. Also, besides the key given to the owner-occupant, there are two other keys to that unit kept in a "locked box," Glassman said, to be made available to the owner only when a key is lost or misplaced. "This was the first complaint of this kind and we certainly regret it," Glassman added. The Smith firm has sold more than 780 condo apartments at Skyline in the Baileys Crossroads complex.

In apartment construction and conversion, the trend is to individual electric metering. Why? The high costs of electrical air conditioning. For instant, International Developers, Inc., which is doing the new Totonda condominium at Tysons Corner and the conversion of the 1,684-unit Park fairfax in Alexandria, is going with individual electric meters at both. Studies by the Institute of Real Estate Management have shown that tenants use about 30 per cent less electrical energy when they control and pay for their own consumption. Joseph R. Schuble of Dreyfuss Brothers, a firm active in property management, says the trend is to install individual electric meters in existing garden apartment communities and to reduce rents to the extent that tenants who hold down their use of electrical utilities by 30 per cent would come out about even the first year. "After that, any rate increases would be absorbed by tenants," he added. He pointed out that the cost of converting to individual metering, even with reduced rents, would be amortized in an average of 16 months for apartment owners who no longer would provide electrical service as part of the monthly rent.

Scheduled to be offered soon in the apartment conversion market is the 100-unit Warwick, vintage 1939, behind the Marlyn in the Idaho and Cathedral avenues area of Northwest. Prices are expected to be set at about $55 a square foot for efficiencies and one-and two-bedroom units. Shannon & Luchs will handle sales.

As of last month, Second Montclair Corp. is handling the development of Lake Montclair community of single-family houses in Prince William County, west of 1-95 near Dumfries. Second Montclair is subsidiary of Chemical Bank of New York, the lender that took over from the prior developer. C. L. Glendenning, the new project manager on the site, said 260 houses are currently under construction.