CHK Architects and Planners Inc., the largest local architectural practice in the Washington area, broke ground this month for their new offices at 1300 Spring St. in Silver Spring in a move that will consolidate their four suburban offices.

The designs for the project, a five-story, 100,000-square-foot structure to be situated on one acre, were selected as the result of an unusual in-house competition at CHK Architects.

"Typically an architectural project like this would be designed by one of the principals of the firm," said Daniel Anderton, a landscape architect at CHK. Twenty-five entries were judged, and a joint entry submitted by Dean Lewis, an architect in the design department and Anderton, a landscape architect there was selected. The final design for the project had input from the partners at the firm.

"The winning design had the best qualities and solved the overall architectural problem best," said Ken Weinstein, a partner at the firm. "Everyone at CHK is always participating in one way or another," he said.

The curtainwall glass and buff-colored precast stone office building will be constructed by Perkins Development.

The building's plans convey a strong horizontal feeling that will conform to the narrow lot that it will be built on. A vaulted glass dome over the Spring Street entrance facing Woodside Park will be one of the dominant features. CHK will occupy the top two floors of the building, and the remainder will be leased.

Bill Agosti, project manager for Perkins, doesn't foresee 1300 Spring St. falling victim to the Silver Spring office glut. Sovran Bank of Maryland and Allied Blueprint, a reprographics firm,have leased space on the ground floor.

"It's certainly comfortable going in knowing that half of the building is leased," Agosti said. "We've had a few inquiries into the balance of the space there." Annual lease rates for the project range from $22 to $23.50 per square foot.

CHK's offices have been in the Silver Spring area since 1954, when the firm was started. "This will be a far more efficient operation," said Lara Todorov, director of marketing for CHK. "Silver Spring is home to us and we like it."

The project will cost $9 million and is being "fast-tracked" for completion in fall of 1988.

In other developments in commercial realty:

Radian Corp., a technical services firm, leased 16,400 square feet at 13595 Dulles Technology Dr., Herndon, from Lee Sammis Associates Inc.

R.M. Vredenburg & Co., an engineering firm, leased 29,000 square feet at Executive Center II, Alexander Bell Dr., Reston, from Network Associates: SMC.

University College, an affiliate of the University of Maryland, leased 15,800 square feet in the Presidential Building, 6525 Belcrest Rd., Hyattsville, from Prince George Center Inc.