What is the finished-connection rule in ANSI Z765?
Published August 27, 2026
Under ANSI Z765, finished area counts only if it is connected to the main body of the house through other finished area. A finished room you can reach only through a garage, an unfinished space, an exterior door, or a pull-down ladder is not part of the house's finished square footage.
Spaces this rule catches
- A finished attic reached by a pull-down stairway or a hatch (a real estate license exam favorite).
- A bonus room over a garage whose only access is a stair inside the garage.
- A garage apartment or in-law suite entered from outside or from the garage.
- A finished basement reached only by an exterior bulkhead door.
What fixes it
A permanent, finished stair or hallway from the house to the space. Once the connection is finished, the space is evaluated on its own merits: ceiling height, finish level, and above or below grade. A bonus room over the garage is the classic example.
Why the rule exists
GLA is meant to describe the house a buyer lives in as one connected unit. A room you have to go outside to reach functions like an outbuilding, and buyers pay for it like one. The rule keeps two houses with the same GLA comparable.