Hamilton County, IN Building Safety: Building Permits (2026)

Before any development activity begins in a special flood hazard area, the applicant must obtain a floodplain development permit, applied for on forms from the floodplain administrator, whom the county commissioners have designated as the Hamilton County Plan Commission Director. At the application stage, the submission must include a description and location of the proposed development, a legal description of the property, a site plan showing existing and proposed grades, the planned lowest-floor elevation in NAVD 88 or NGVD, and, for non-residential buildings, the elevation to which the structure will be flood-proofed; any watercourse alteration requires a hydrologic and hydraulic study submitted to DNR and, ultimately, FEMA as a letter of map revision.

Once the lowest floor is set, before framing continues, the applicant must submit a certification of its as-built elevation prepared by a registered land surveyor or professional engineer (or, for floodproofed buildings, an Indiana professional engineer or architect); work done before that certification is submitted is at the applicant's own risk, and the administrator can issue a stop-work order for missing or deficient certifications. A final elevation certificate is required again once construction is complete. The administrator also confirms that any required Indiana DNR floodway construction permit or federal authorization was obtained before the local permit issues, and keeps all permit records, damaged-structure inventories, and elevation certifications on file for public inspection.