Habitable rooms must be a minimum of 70 square feet, with one wall not less than seven feet in length. Although the kitchen is considered a habitable room, it is exempted from the minimum area requirement (International Residential Code R304).

    There are also two requirements in earlier versions of the code that have been eliminated: formerly, at least one room had to be 120 square feet or more, and the minimum area of a kitchen was set at 50 square feet. 

     Any area of a room that has less than a seven foot flat ceiling, or any area with a sloped ceiling that is less than five feet high, cannot be counted towards the minimum square footage requirements. Bathrooms, hallways, closets and utility rooms are not counted as habitable spaces.

   By the way, no minimum total square footage of a residence is addressed by the International Residential Code (IRC) or Florida Building Code (FBC), but is usually specified by local zoning and deed restrictions.

    Also, see our blog post What is the definition of a habitable space in the building code? 

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Here’s links to a collection of our other blog posts about STRUCTURE AND ROOMS:

• What are the building code requirements for notching and boring holes in a wall stud? 

• What causes dark or light "ghost" lines on ceilings and walls?

• Can you access or exit a bedroom through another bedroom?

• What is the difference between a carport and a garage? 

• What are simple ways to find the cause of a ceiling stain?

• Why is my garage ceiling sagging? 

• Why do the floors slope in this old house? 

• What are the common problems when a homeowner converts a garage to conditioned living space, such as a family room?

• How can I tell if a wall is load-bearing? Which walls can I take out? 

   Visit our STRUCTURE AND ROOMS page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.