Many houses today are built in tracts. The designs are standardized and many of the parts are prefabricated in factories. The line between site-built and factor

Many houses today are built in tracts. The designs are standardized and many of the parts are prefabricated in factories. The line between site-built and factory-built housing is blurring. http://en.wikipedia.org/wiki/Tract_housing http://en.wikipedia.org/wiki/Tract_housing Early tract homes were often identical, but more recently built tract homes no longer look identical from the exterior; variations range from mass-produced homes with superficial, cosmetic differences to multiple variations in footprint, roof form, and materials. In addition, floor plans may be reversed or rooms or garage bays added or removed. Builders or buyers of new homes may also be able to specialize custom upgrades. So, it seems that modern tract homes are made similar to the way cars are: based on standardized designs, but available in various models and with options. From the wiki link above: Components such as roof trusses, plumbing trees, and stair systems are often fabricated in factories and installed on site. This allows contractors to reduce prices, which in turn can make homes more affordable Here are some new housing tracts in the Bay Area: http://www.lennar.com/New-Homes/California/San-Francisco http://www.lennar.com/New-Homes/California/San-Francisco The prices are locked-in before construction, so the customer will know what he will be expected to pay. There are also tract homes that have been preconfigured and completed (built) before sale, and have definite prices: http://www.lennar.com/New-Homes/California/San-Francisco/Palisades-At-Mt-House http://www.lennar.com/New-Homes/California/San-Francisco/Pal... Purchasing such a home is analogous to purchasing a new car off of a dealer's lot (instead of ording one shipped from the factory with custom options) - it isn't custom configurable, but it is available right away.