Most of the money went for upgrades to mechanical systems and elevators, but roughly $3 million was spent to create the green roof.
Lauder asked Selldorf to restore the building as much as possible and, at the same time, to make it function as a contemporary museum, with modern lighting, mechanical systems, and elevators.
The $18 million project also involved installing new mechanical systems, two elevators and high-tech wiring as well as cutting windows from the building's eastern facade, which overlooks landmark carriage houses.
Mr. Davis said that the managing agent should ensure that the building's mechanical systems -- including elevators, water heaters, trash compactors and heating, ventilation and air-conditioning -- are inspected in the next couple of weeks and repaired immediately if defects are found.
(The northern walls, which would let in the kind of indirect sunlight artists and curators love, are largely blocked by mechanical systems and a freight elevator).
Renovating the buildings will include installing new mechanical systems as well as an elevator.
And a tired 1951 building at 655 Madison Avenue, at 60th Street, is getting an extensive makeover, including a gray-glass facade, and new elevators and mechanical systems.
"Other than the facade, it's going to be a new building, with new elevators, new mechanical systems, new bathrooms and a new central courtyard," he said.
He had jumped into a height race against the Chrysler Building, then under way on a plot of 37,000 square feet, and the Empire State Building, just about to begin on 91,000 square feet, and the upper floors of those projects were already considered far too small, after the space allotted to elevators and mechanical systems.
But the core of each of the towers -- the space housing elevator banks and mechanical systems -- has been reduced, both to accommodate more retail space at ground level and to reduce the bulk of the buildings, allowing more sunlight to reach the ground.
