How many houses are there in America and how many have yards?

Smoore --

Thank you for the interesting question.  Every two years the U.S.
Census conducts a housing survey.  I'm using the 1999 data because
it's easiest to access on the web.  The 2001 survey is a 538-page
document that takes a L-O-N-G time to download even on a high-speed
link, though I've provided links to both below.

There are 115.3 million housing units in the U.S.  Of those, 78.8
million are single-family detached homes and mobile homes.  Mobile
homes are 8.4 million of those.  The balance of the units are
apartments, cooperatives or condominiums.

The homes on more than 1/8 acre (5,500 square feet) are those likely
to have a yard.  They account for 72.1 million or 92% of the total.

You might be interested to see the breakdowns in lot sizes:
1/8 to ¼ acre: 25.9 million
¼ to ½ acre: 13.1 million
½ to 1 acre: 11.4 million
1-5 acres: 15 million
5-10 acres:  2.7 million
10 acres or more: 4.3 million
Median acreage: .33


"American Housing Survey for the United States" (1999):
http://www.census.gov/hhes/www/housing/ahs/ahs99/tab1a3.html

"American Housing Survey for the United States" (2001):
http://www.census.gov/prod/2002pubs/h150-01.pdf

Great question!  Now how many of those yards have leaves in them
waiting to be raked?

Please let us know if anything is unclear about this answer.

Best regards,

Omnivorous-GA