747 Wing House
The 747 Wing House was built on the site where existing Duquette structures had burned. Some of the materials from the previous building were used as walkways. The use of the existing pad minimized site grading. The foundation used many of the existing concrete retaining walls but they were rebuilt and reinforced as required to meet new code regulations. This greatly reduced the amount of concrete needed to make the foundation and new walls. Because the wings are only supported in four primary places to the ground, the foundation was further minimized. Both main wings are held up entirely by the four large mounts that the engines originally hung from. By designing the weight distribution on the mounts, it allowed for the outside walls of the building to be made of high efficiency self-supporting glass instead of conventional load-bearing wooden walls. This maximizes solar gain for heating and allows the entire building to be opened to the outside. This also keeps it cool in the summers and minimizes the need for artificial light.
Construction loan
Beyond this guideline, the next most common rule is a minimum cash injection requirement. Even if, for example, a business might be able to afford a monthly payment of a loan high enough to pay for the entire construction project, many lenders would require them to instead use a certain minimum portion of their own cash to complete the project. The reason for this is both to psychologically and economically tie in the owner with the project (hopefully making it less likely that they would walk away from the project if something goes wrong), and to give the lender a cushion whereby if something goes wrong they are more likely to be able to sell the real estate at a value that would better cover the loan amount. This guideline is often termed a "loan to cost" requirement, i.e. the lender will only loan up to 85% of the project costs.