Many old quarters were completely destroyed in the process, replacing them with more efficient and faster-built concrete buildings.

"We looked for alternate locations, but this is an efficient and well-designed building," she said.

The efficient building can be operated more cheaply, and the savings mount up year after year.

In most cases, the decision to make an efficient building still rests with the client.

But, he added, an "efficient" building could reap as much as 30 percent in energy savings each year.

We were close to signing up to build a million square feet in what would have been a more efficient building.

It was not a particularly efficient building for theater production.

It had already been cited as an efficient building by the Energy Star program.

To be precise, energy savings for efficient buildings average 30% over conventional buildings.

The workforce was reorganized to become more efficient and more buildings were erected.