When does a crawlspace become basement?

[DeseretJohn]

I'm working for a second local county assessor's office and have never received an answer to this question. On occasion I run across what would have to be called a "finished crawlspace", nice floor covering light fixtures, windows - all the usual things you'd associate with living area, but the ceiling is just 5 feet high making it clearly NOT living space unless you're an oompa-loompa (sp?).

I ran across another situation this week in a large custom home on hillside with an apparent double basement. A portion was built as a single basement with very vaulted ceiling, with and an adjacent side having typically sized rooms on the first basement level and the lower level having a ceiling height of about 6' 7" throughout. The lower level was compartmentalized into several "rooms, accessed through what appeared to be typical doors (though as I type this I realize all doors I've purchased are 80" tall), and were otherwise appointed as living space.

It seems everyone has a rule-of-thumb as to what constitutes a minimum ceiling height for living area, but I seem to recall reading somewhere a very specific standard that defines what is an acceptable height and what is not. Can anyone in the AF empire help me to this clarify this dilemma?

 

[Mike Kennedy]

Because it varies from municipality to municipality.......the Building and Zoning Codes (if exist/applicable) typically give you the specs you're seeking as well as whether a building permit and certificate of occupany are required for finished "basement".

also see "ANSI" standards while not the "bible" due to local B&Z codes.......generally recognized standards for GLA.

Basements and Below-Grade Floor Areas

The ANSI standards make a strong distinction between above-grade and below-grade floor area. The above-grade floor area is the sum of all finished square footage which is entirely above ground level. The below-grade floor area includes spaces which are wholly or partly below ground level.

Disregard the old rules of thumb that allow you to include below-grade areas if they are less than five feet below grade, or if less than half the area is below grade. If the house has any areas below the natural grade, measure that whole level separately. Even if the below-grade areas are fully finished, they are not part of the finished floor area according to ANSI standards.

A 16-page booklet describing the ANSI standards with examples and illustrations can be purchased for $20.00 (plus $4.00 shipping and handling) from the National Association of Home Builders (NAHB) Research Center in Maryland at 301-249-4000.

 

[DeseretJohn]

A different can of worms.....

I've been involved in some debates as to whether something is below grade and basement or above grade and GLA when the house is built on a grade or has some unique backfill. The question I'm posing in this thread isn't an above/below grade issue though - it's a ceiling height issue.

In the home I'm puzzling about, the area in question is clearly below grade. The house is still under construction so the final finish is still in question. Probably 1000 - 1300 sq ft is broken into five or six "rooms" with light switches, painted ceilings, regular doors and door knobs, individual heat/AC vents, the entire area is uniformly 6' 7" from ceiling to floor.

The builder told be the plans at first called for the area to be just 4 1/2 feet tall but the HO specifically asked for the area to be made taller so that at over 6' tall he wouldn't have to stoop. Apparently when the homeowners received their appraisal, they were surprised and dissappointed their appraiser did not count the area as finished bsmt/living area but just as storage.

If it came down to defending a label one way or the other, would ANSI standards rule (unless trumped by local requirements), and if so, what would ANSI say?

 

[Joshua Fookes]

I'd go with ANSI

from ANSI Z765-2003

Ceiling Height Requirements
To be included in finished square footage calculations, finished areas must have a ceiling height of at least 7 feet
(2.13 meters) except under beams, ducts, and other obstructions where the height may be 6 feet 4 inches (1.93
meters); under stairs where there is no specified height requirement; or where the ceiling is sloped. If a room’s
ceiling is sloped, at least one-half of the finished square footage in that room must have a vertical ceiling height of
at least 7 feet (2.13 meters); no portion of the finished area that has a height of less than 5 feet (1.52 meters) may
be included in finished square footage.

I'd call it a finished crawl space, not a basement, and not part of the GLA for sure. Typical door heights are 6'8", your subject's crawl space does not even have typical doors.