Expert: Stephen Major - 9/6/2007

Question
Hi. I have a question about calculating the square footage of an apartment/home. Is the square footage determined by adding up all the dimensions of each room?

Answer
Danielle,

Although there is a published standard for determining the area of a house (ANSI Z765-2003), generally it is common practice (for houses) to include the square footage of all occupied (climate-controlled) floors, by measuring the outside dimensions of the building. This method will include the area taken by walls, closets, partitions, etc.  For two-story homes the stairwell area is counted only once.  For example, a 2 story colonial house that is 28' x 42' in size would have a gross occupied area of 2352 square feet, minus aprx 30 square feet for the stairwell for a total of 2322 sq. ft.  Unfinished basements are typically excluded from these calculations.

This site has some good information:
http://www.coolhouseplans.com/calculating-square-footage.html

It is always best, when describing the square footage of a building, to identify the method used to determine it.  

I hope this helps. Please let me know if you need additional information.

--Steve Major