Homes in Wasilla and almost everywhere else in the Matanuska-Susitna Borough did not receive building inspections until 1992 when the Alaska Housing Finance Corporation required them for financing. Since that date, most homes are inspected during construction. The city of Palmer required building inspections and permits previous to 1992.
During the real estate boom of the early 1980’s , Wasilla was one of the fastest growing cities in the country. Builders were selling houses as fast as they could put them up. As a result, they tried to to find ways to build homes faster. One bottle-neck in the process was the lack of concrete workers to put in the foundations. Contractors found a way around this by building wood foundations. About 1/3 of the homes built between 1980–1985 had wood foundations.
These foundations generally have a concrete footer on the very bottom. Almost any experienced construction worker can build a concrete footer, but a concrete block foundation 
wall requires special skills. These wood foundations used treated wood so that it doesn’t rot. I suppose it may eventually disintegrate but I have never witnessed this.
It is completely legal to use this type of foundation and it can also be structurally sound as long as the work is done correctly. However, most of the foundations erected during the early 1980s have since been modified to make them more structurally sound. Hardly any new homes are built this way today and there is a reason for that.
