The Construction of a House

This is giong to be a multi-part post, because it is so big.

The construction of a house is a very detailed, step-by-step process. This process is site preparation, foundation, basement, crawl space, floor, walls, roof, porch, windows and doors, roofing, siding, plumbing, rough plumbing, rough electrical, insulation, drywall, garage slab, and finishing up.

Site Preparation-
The first crew on the site handles site preparation. Often, this crew and the foundation crew are the same people, but sometimes not (especially if there are a lot of trees on the lot). Houses are generally built on a foundation that is either a basement, a crawl space or a slab. The site-preparation crew typically arrives on the site with a backhoe and/or bulldozer. The crew's job is to clear the site of any trees, rocks and debris, level the site if necessary and dig as necessary for the foundation being built. The example house shown here is built on a crawl space. For a crawl space, the site preparation crew digs a set of trenches and holes. Concrete is poured into these trenches and holes and will act as the interface between the foundation wall and the ground. The concrete in the trench is generally about 18 to 24 inches wide (45.72 to 60.96 cm) and 18 to 24 inches deep. Once it hardens, it forms a massive concrete "beam" on which the house rests. The width of this concrete beam is controlled by the compressibility of the soil. In light soils, the beam will be wider to try to spread out the load, while in heavy clay soils it can be narrower.
If the site slopes, the concrete beam is stepped. Concrete takes approximately four weeks to cure to full strength (depending on the weather), so once the concrete is poured nothing will happen for some period of time while the initial curing takes place. If this house had been built on a basement, the site-prep crew would have dug a square hole about 8 feet deep. If this house had been built on a slab, the site-prep crew would have trenched around the outside approximately 2 feet deep and then completely leveled the area for the pad.

Foundation-
Slabs, basements and crawl spaces are the three main foundation systems used on houses. In wet and coastal areas, it is sometimes common to put houses up on posts as well. The slab is probably the easiest foundation to build. It is a flat concrete pad poured directly on the ground. It takes very little site preparation, very little formwork for the concrete and very little labor to create. It works well on level sites in warmer climates -- it has problems up north because the ground freezes in the winter and this freezing can shift the slab at worst and at least lead to cold floors in the winter. Around the edge of the slab, the concrete forms a beam that is perhaps 2 feet deep. The rest of the slab is 4 or 6 inches thick. A 4- or 6-inch layer of gravel lies beneath the slab. A 4-millimeter sheet of plastic lies between the concrete and the gravel to keep moisture out. Embedded in the concrete is 6-inch by 6-inch wire mesh and steel reinforcing bars. You will often hear this sort of foundation referred to as a "floating slab" -- it "floats" on the soil, with the deeper concrete around the edge holding it in place. In northern climates, the concrete around the edge has to extend deep enough to remain below the frost line in winter.
One thing about a slab is that the sewer pipe, and sometimes much of the electrical conduit, has to be put in place before the concrete is poured. The sewer pipes are actually embedded in the slab.