Manufactured Homes and Mobile Home Parks and Sales
Napa Valley, San Francisco North Bay, Ca. USA

Mobile homes are built in factories, rather than on site, and then taken to the place where they will be occupied. They are usually transported by tractor-trailers over public highways. They are less expensive per square foot than site-built homes, and are often associated with rural areas and high-density developments, sometimes referred to as trailer parks. In the UK and USA they are at times referred to as "communities".

The term factory built home specifically refers to a home built entirely in a protected environment under a federal code set by the US Department of Housing and Urban Development (HUD). These houses are usually placed in one location, often a rented lot, and left there permanently. However, they do retain the ability to be moved, as this is a requirement in many areas. Behind the cosmetic work fitted at installation to hide the base, there are strong trailer frames, axles, wheels and tow-hitches.

These homes are not large recreational vehicles. The latter are more properly called travel trailers, motor homes or RVs, and they are usually parked at facilities called trailer parks, trailer courts, or RV parks for short terms.

The two major sizes are single-wides and double-wides. Single-wides are sixteen feet or less in width and can be towed to their site as a single unit. Double-wides are twenty feet or more wide and are towed to their site in two separate units, which are then joined together. Triple-wides and even homes with four, five, or more units are also built, although not as commonly.