Sale of a 13,700-square-foot site at the southeast corner of 13th and I streets NW has been made to 1250 Eye Street Associates by William Robinowitz of Washington. Julien J. Studley Inc., which represented the purchaser, said the purchasing group plans to build a 150,000-square-foot office building, where the Washington law firm of Surrey and Morse will be the major tenant.

The Studley firm also announced that Kaplan, Smith and Associates, financial consultants, has leased 14,000 square feet at 919 18th St. NW.

DeRand Realty Corp. of Arlington has announced its purchase of the Fairlington Shopping Center for $1.4 million. DeRand plans to syndicate the ownership of the 23-tenant shopping complex at Quaker Lane and Fern Street, near the Fairlington and Parkfairfax condominium complexes. Richard K. Shea, president of DeRand, said the property will be substantially renovated.

The Braedon Companies announced Union Carbide Corp. is leasing 9,000 square feet of commercial office space at 1100 15th St. NW., a building how being completed for Prudential Insurance Co. of America. Occupancy is scheduled early in 1982. Union Carbide will occupy the top floor of this building.

Tysons Corner, the fast-growing center of commercial development in Northern Virginia, now has nine buildings under construction, which will bring the total office space in the area of the Beltway and Routes 123 and 7 to 8.5 million square feet by the end of this year.

Coakley & Williams Inc., a Kensington-based developer and builder, announced that Systems Engineering Laboratories is the first tenant in its new Maryland Trade Center at 7500 Greenway Center Drive, Greenbelt. The site of the 16-story building is near the Baltimore-Washington Parkway and the Beltway in Prince George's County. SEL has moved into 12,000 square feet of space, where 32 employes will work at a combined service center, spare-parts depot and computer demonstration area.