Scientists and contractors, learning as they went, installed venting systems in them free of charge.

"A contractor can install a standard, two-stop dumbwaiter in four to six hours" for about $750, he said.

One private contractor would build and install all the structures, giving some uniformity to the streetscape.

If the Government accepts the bid, the contractor installs the new equipment at the contractor's expense, an approach taken by many private building owners.

After this, other contractors install the access stairs or ramps, furniture, home appliances, and water.

Another mayor has a contractor install a waterfall in his backyard.

The contractors also installed electronics equipment that was prone to failure in open-sea conditions.

In Phase 2, contractors will install three sets of solar panels around the mansion and its grounds.

They are living in a hotel while contractors install new kitchen and bathroom fixtures.

To stabilize the movement, contractors installed a tuned mass damper on the 58th floor.