Interpretation #9469
Published December 17, 2025
Original Request
- Code Version
- 2023
- Code
- EXTBLDG
- Code Description
- Chapter
- 11
- Section
- 1103.5 1.3
- Topic
- Flood hazard areas, “. . .shall not create or extend any nonconformity”
Question
Is it the intent of the Florida Building Code Section 1103.5 (1.3) to prohibit the footprint expansion of a “floodplain” noncompliant building (the building is within the Special Flood Hazard Area, floodplain, Zone AE)?
Answer Published 12/12/2025 at 7:39 AM
On behalf of FDEM Office of Floodplain Management:
No, the intent of FBCEB Sec. 1103.5 is not to “prohibit footprint expansion” of non-conforming buildings. See notes below with FDEM’s understanding of “shall not create” and “shall not extend.”
The confusion is in the phrase “shall not create or extend any nonconformity.” The FBCEB uses that phrase or similar in a number of sections. The question asked arises because an addition, by its nature, “extends” the footprint. That was not the intent of the cited section when it was proposed for the International Existing Building Code on which this section of the FBCEB is based.
Note that in FBCEB Sec. 1103.5 Flood hazard areas, additions are characterized as “structurally interconnected” (meaning structurally part of the base building) and “not structurally interconnected” (meaning the addition is, in effect, a separate building). Starting with the 8th Edition (2023), both Sec. 502.2 [Additions] Flood hazard areas, and Sec. 1103.5 [Additions that are structurally connected] have specific provision that apply to additions that do not constitute Substantial Improvement.
FDEM considers “shall not create” to mean the addition must not create any new nonconformity. Examples of this would be if the area under the addition is enclosed, but the enclosure does not match the enclosure requirements of the base building depending on flood zone (e.g., flood openings, materials, breakaway walls) and if the utilities and equipment that serve the addition do not match the elevation of the floor.
We consider “shall not extend” to mean the addition must not make any existing nonconformity worse (the same meaning suggested by use of “not less conforming”). One example of how an addition, especially a non-substantial improvement addition, might make a nonconformity worse is if the base building in Zone V has a column or pile foundation and the addition does not have a Zone V compatible foundation (and match the elevation of the base building).
No, the intent of FBCEB Sec. 1103.5 is not to “prohibit footprint expansion” of non-conforming buildings. See notes below with FDEM’s understanding of “shall not create” and “shall not extend.”
The confusion is in the phrase “shall not create or extend any nonconformity.” The FBCEB uses that phrase or similar in a number of sections. The question asked arises because an addition, by its nature, “extends” the footprint. That was not the intent of the cited section when it was proposed for the International Existing Building Code on which this section of the FBCEB is based.
Note that in FBCEB Sec. 1103.5 Flood hazard areas, additions are characterized as “structurally interconnected” (meaning structurally part of the base building) and “not structurally interconnected” (meaning the addition is, in effect, a separate building). Starting with the 8th Edition (2023), both Sec. 502.2 [Additions] Flood hazard areas, and Sec. 1103.5 [Additions that are structurally connected] have specific provision that apply to additions that do not constitute Substantial Improvement.
FDEM considers “shall not create” to mean the addition must not create any new nonconformity. Examples of this would be if the area under the addition is enclosed, but the enclosure does not match the enclosure requirements of the base building depending on flood zone (e.g., flood openings, materials, breakaway walls) and if the utilities and equipment that serve the addition do not match the elevation of the floor.
We consider “shall not extend” to mean the addition must not make any existing nonconformity worse (the same meaning suggested by use of “not less conforming”). One example of how an addition, especially a non-substantial improvement addition, might make a nonconformity worse is if the base building in Zone V has a column or pile foundation and the addition does not have a Zone V compatible foundation (and match the elevation of the base building).
Commentary
None.