Some key links and data regarding subdivision development in the US since the 2008 housing collapse.
The US Census 2017 Characteristics of New Housing survey provides a highly detailed collection of data regarding new housing construction during the period 2009-2017. It includes data on house and lot size, numbers constructed by type, construction types, and various systems and features (heating, plumbing, sewage, parking, etc.).
According to this survey, 61% of new single-family houses built nationwide in 2017 were part of a Homeowners Association and thus a subdivision. That has been steadily rising since 2009, when it was 46%. The area with the most subdivision development is, not surprisingly, the South and the West.
Also according to this survey, the median lot size in 2017 is 8,825 sqft, down from almost 11,000 sqft in 2009 (a change driven primarily by a reduction of lot size in the Northeast, Midwest and South). Median house floor areas has increased slightly from 2009 to 2017, from 2,135 sqft to 2,426 sqft. This is part of a much larger trend of house size increases since at least 1973, at which time the median floor area was 1,525 sqft.
The National Association of Housing Builders also carried out a survey of housing construction in 2016. According to this survey, the median subdivision size is 26 acres, 17 acres of the subdivision site dedicated to housing. With a median of 45 units per subdivision, this leads to a median distribution of 3.2 units per acre. A more recent survey by NAHB has shown that housing size has started to decrease over the past three years:
Recent articles on the demand, regulations, and economics driving the ongoing increase in housing size over the past century include: