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.
Deep foundation
A main consideration regarding timber piles is that they should be protected from rotting above groundwater level. Timber will last for a long time below the groundwater level. For timber to rot, two elements are needed: water and oxygen. Below the groundwater level, dissolved oxygen is lacking even though there is ample water. Hence, timber tends to last for a long time below groundwater level. In 1648, the Royal Palace of Amsterdam was constructed on 13659 timber piles that still survive today since they were below groundwater level. Timber that is to be used above the water table can be protected from decay and insects by numerous forms of wood preservation using pressure treatment (alkaline copper quaternary (ACQ), chromated copper arsenate (CCA), creosote, etc.).