In 2002, there were an estimated 2,386,848 housing units, 2,142,645 of which were occupied; 68.7% were owner-occupied. About 64.8% of all units were single-family, detached homes. Rural areas had a higher proportion of deficient housing than urban areas, and substandard conditions were three times as common in units built before 1939, which account for about 24% of the existing housing stock. In 2002, utility gas was the most common energy source for heating; about 804 units were equipped for solar power. It was estimated that 53,261 units lacked telephone service, 10,703 lacked complete plumbing facilities, and 11,711 lacked complete kitchen facilities. The average household size was 2.47 people.
In 2002, 38,208 new privately owned housing units were authorized for construction. The median home value was $122,259. The median monthly cost for mortgage owners was $1,088. Renters paid a median of $580 per month. During 2002, Wisconsin received more than $235.3 million in community planning and development aid from the US Department of Housing and Urban Development.
The Department of Veterans Affairs makes home loans to veterans. The Housing Finance Authority, created by the legislature in 1971, raises money through the sale of tax-exempt bonds and makes loans directly or indirectly to low- and moderate-income home buyers. Wisconsin's state building code, developed in 1913 to cover construction of all dwellings with three or more units, was revised in the late 1970s to cover new one- and two-family dwellings. Local housing codes prescribing standards for structural upkeep and maintenance in existing buildings are in force in all large cities and in many smaller cities and villages.