Washington architect Arthur Cotton Moore has won an architectural competition with an innovative design to remodel the Old Post Office Building, the cornerstone of the long-promised Pennsylvania Avenue redevelopment. The $16 million remodeling would combine shops with a spectacular courtyard which rises 196 feet to an immense glass roof.

The great glassed-over courtyard (cortile) of the structure would be surrounded with shops and a restaurant on the basement, first and mezzanine floors. Federal offices on the second through ninth floors would circle the open center space with arched corridor/balconies serving as "streets in the sky." The landmark clock tower would become an observation platform complete with glass elevator.

"The whole plan is based on making the building a bridge between the local city and the federal capital," Moore said last night.

Selection of Moore's bold plan over a safe textbook restoration scheme marks a new direction for the General Services Administration, which has been criticized for bland architecture, Joel Solomon, the GSA administrator, annouced Moore's selection last night.

Moore is in a joint venture with McGaughy, Marshall and McMillian of Norfolk, Associated Space Design of Atlanta and Steward Daniel Hoban of Washington. Construction is expected to begin September, 1978, after a year of design work.

The Old Post Office Building, the first federal office in the area, has seen its fortunes rise and fall with the avenue. The Richardson Romantic Building, finished in 1899, has stood trembling on Pennsylvania Avenue in fear of its life ever since the neo-classical Federal Triangle was built. As soon as it was finished, one newspaper suggested dynamiting it. Its advocates, growing in strength over the years, have fought for its preservation asa "city sculpture" to lighten the ponderous Triangle.

Moore's plan is full of innovative ideas - from solar collectors in the glass roof to offices through floors two through nine to shops in the basement and first floor.

"The Federal Triangle has served as a Chinese wall to the city," Moore said. "Tourists come down to the Mall from their Bi-de-we motel in the suburbs and go back without ever coming into the city.

"What we hope to do is make a place so attractive, we will bring together tourists from the Mall, government workers from the Federal Triangle and city shoppers."

Moore would cut a 100 by 150 foot hole in the main floor and install a baroque staircase (and perhaps an escalator) into the basement floor. Concress has just recently authorized the mixed use of federal buildings for both government and commercial, and 50,000 feet of space will be leased to private business.

The present south loading dock would be made into an important entrance to the ground floor (now the basement) through asculpture court. Another entrance to the lower floor would be made on the northeast through what are now windows.

Moore's plan also calls for a Metro entrance and atourmobile stop in the sculpture court, which would be made in the curving south entryway. Current Pennyslvania Avenue Development Corporation plans call for a triangular tree court in the Pennsylvania Avenue entrance.

Floors two through nine would provide 142,000 square feet of federal office space. The choice fifth floor with its elaborate plaster moldings might go the National Endowment for the Arts, which championed the recycling of the building. The National Endowment for the Humanities and other arts-related agencies would have offices on the upper floors, to turn the building into a United States culture center.

The upper floors all have balconies onto the cortile. The Federal space, for security, would be controlled by lobbies around each of the elevators to the upper floors. William R. Lawson chairman of the competition board, said this seperation between shoppers and offices workers was one of the prime reasons Moore was chosen.

The Moore plan pays particularly attention to energy saving. The windows would all be openable. Solar collectors, shaped like fins, would work like venetian blinds against the glass skylight to control glare while collecting solar energy.

The ninth floor, now a gloomy attic, would be opened up with skylights in the roof gable and used for office space.

Moore was selected through a widely-acclaimed new method, just recently started by GSA. Ninty-three of some of the country's best known architectural firms entered the architectural competition. From these, 10 were chosen to be interviewed and from them three chosen to submit (for a $46,000 fee) a preliminary plan.

The three were: Huge Newell Jacobsen of Washington with Shepley, Bulfinch, Richardson & Abbott and Desmond and Lord Inc. of Boston: Faulkner, Fryer & Vanderpool of Washington; and Moore and his joint venture. The three had from April 9 until last Wednesday to design their plans.

"We really were looking for a design approach," William Lawson, chairman of the competition board said, "rather than a finished plan. What got us about Moore was the excitement he brought to the conception. He made a dramatic innovative proposal. Faulkner, et al. did a textbook, careful, safe restoration plan. Jacobsen's design was a compromise between the other two.

"I suppose you are right to say this is one of the clearest instances when GSA had the choice between a safe plan and an innovative one and took the innovation."

GSA has been criticized for years for dull designand the competition was designed to encourage a more spirited approach to government building .

Joel Solomon, the newly-appointed GS administrator, was especially interested in the competition. He attended the Wednesday hearing, and in the middle, raced out to see the Old Post Office for himself. He climbed all the way into the dark tower and inspected the archades and the roof, now asphalted over.

Moore, a Princeton graduate is a sixth-generation Washingtonian. The 24-year-old architect has already won six honor awards this year. Among his best known works are: Canal Square, the Foundry, Madeira School, and the Cairo apartments. Of these, all except the school are old, derelict buildings, remodeled in a clean lined, bare brick contemporary fashion.

Moore first became interested in the Old Post Office in 1971 when the Washington Post architecture critic Wolf Von Eckardt asked his ideas on reusing the old structure after Don't Tear It Down preservation society and architect John Wiebenson had mounted a campaign to save the biulding , against one of the recurring plans to demolish it.

The GSA review board of architects and engineers included Karel Yasko, Kent Slepicka, Claude Bernier and Dwain E. Warne, assisted by 20 technical consultants.

The Old Post Office was designed as the name suggests for that use beginning in 1892. It was the first government building to have its own electrical power plant. It still has the largest uninterrupted interior space in Washington and the only opencaged elevators.

Sadly, according to the story, a postmaster fell down one of the elevator shafts during the opening day celebration.

Flag Day is said to have begun here when, on June 14, 1908, post office employees raised the largest correctly proportioned American flag from the skylight falling seven stories down.

Originally, mail was sorted in a glass roofed section of the first floor in the cortile. In the recent years the building has been used temporarily by a succession of agencies. The longest tenant has probably been the FBI, which still hangs a picture of the late FBI director J. Edger Hooverin their lobby.