# Gross floor area vs gross building area **URL:** \ **Category:** Programming & Analysis\ **Created:** [May 8, 2024, 11:32am UTC](https://community.blackspectacles.com/t/gross-floor-area-vs-gross-building-area/5840 "2024-05-08T11:32:20Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![potoczakhalle](https://blackspectacles.com/uploads/images/8.png) [@potoczakhalle](https://community.blackspectacles.com/u/potoczakhalle)\ **Post date:** [May 8, 2024, 11:32am UTC](https://community.blackspectacles.com/t/gross-floor-area-vs-gross-building-area/5840/1 "2024-05-08T11:32:21Z")
how is the gross floor area measured? how is the gross building area measured? The IBC says inside face of exterior walls, but some I’ve also seen outside face of exterior walls. Just wondering if exterior walls are included or not. Thanks! ---
**Author:** ![kiaragalicinao](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.blackspectacles.com/kiaragalicinao/32/1607_2.png) [@kiaragalicinao](https://community.blackspectacles.com/u/kiaragalicinao)\ **Post date:** [May 8, 2024, 4:24pm UTC](https://community.blackspectacles.com/t/gross-floor-area-vs-gross-building-area/5840/2 "2024-05-08T16:24:10Z")
Hi @potoczakhalle ! Thank you for your question. Per 2021 IBC (see Section 202: Definitions): **Gross Floor Area** is defined as “the floor area _within the inside perimeter of the exterior walls_ of the building under consideration, exclusive of vent shafts and courts, without deduction for corridors, stairways, ramps, closets, the thickness of interior walls, columns or other features…” **Gross Building Area** is defined as “the area included _within surrounding exterior walls_, or exterior walls and fire walls, exclusive of vent shafts and courts…” Simply put - Gross Floor Area _does not_ include exterior walls and Gross Building Area _does_ include exterior walls. I hope this helps! Please let me know if you have any other questions. Happy studying! Kiara Galicinao, AIA, NCARB Black Spectacles