Between 65 million and 70 million square feet of office space could be built in New York City over the next 25 years, more space than in all of downtown San Francisco. The gradual build-up will be “a very orderly delivery of space compared to the boom and bust cycles we had in the 1970s and ’80s,” said Mary Ann Tighe, CEO of CB Richard Ellis’ New York office. The biggest construction area will be on the far West Side, from the Hudson rail yards between 30th and 33rd streets and north to 42nd Street. The city plans on 24 million square feet of new office space being built there.