Plans have been announced for a $380 million commercial and residential development to be built on the site of the former Washingtonian Country Club in Montgomery County between Rockville and Gaithersburg.

The mixed-use project, which would be developed on 211 acres by Ackerman & Co., an Atlanta-based real estate firm, is located at the intersection of Interstate 270 and Shady Grove Road.

Ackerman is developing the project for Eig Enterprises Inc., owners of the property which had been the site of a 400-acre complex that included a hotel, apartment building, two golf courses, tennis courts and swimming pools.

The proposed Washingtonian Center will be built in a parkland setting of lakes, ponds and walking, jogging and bike paths.

It will contain between two and three million square feet of office space, 1,500 multifamily residential units for lease and sale and an 800-room hotel and convention center.

Also included in the plans are provisions for a communications center for satellite conferences and copying and centralized computer services, a day-care center, an indoor-outdoor athletic complex and a restaurant mall.

The goal in developing Washingtonian Center is "to create an environment in constant harmony with the individual's life experience and pursuit of happiness," said Charles S. Ackerman, president of the firm, which also has an office in Baltimore.

The master planning phase of the project is expected to be completed by the end of 1983. No date has been announced for completion of the development phase, however.

Ackerman & Co. is an international, diversified firm with offices also in Chicago, Houston, London and Rotterdam. The company is partially owned by Blauwhoed B.V., of Rotterdam, the Netherlands, which bought a half-interest in 1974.

Fire swept the Washingtonian Country Club building in 1976, causing damage estimated at several million dollars.