Rehabilitation of existing buildings requires much less initial investment of energy than constructing comparable new facilities:
The Grand Central Arcade, an adaptive reuse of a hotel in Seattle's Pioneer Square Historic District, required less than one-fifth as much energy for rehabilitation materials and construction activities than would have been needed to produce the materials for and build a comparable new facility. The rehabilitation "savings" came to more than 90 billion Btus or over 70,000 gallons of gasoline.
Rehabilitation of the Lockfield Garden Apartments would potentially require only one-third as much energy for materials and construction processes as a new complex providing the same services. In this case, the rehabilitation "savings" would be equivalent to over 2,250 Btus or almost 2 million gallons of gasoline.
An extensive rehabilitation of "Austin House," a 3-unit apartment adaptive reuse of a Capitol Hill carriage house in Washington, D.C., left only the exterior shell intact. Even so, the rehabilitation materials and construction activities required less than half as much energy as would have been required in the materials and building of an equivalent new structure. Initial rehabilitation "savings" for this small structure (2,700 square feet) are over 1000 million Btus or over 8,000 gallons of gasoline.