Posted October 25, 2026. The county and FEMA pages and the federal regulation quoted here were checked on October 23, 2026. Deadlines, thresholds and contacts change — our city-by-city page carries the current answer for each Pinellas jurisdiction.
If your home in unincorporated Pinellas County is in the floodplain, the county does not keep storm repairs and a remodel in separate columns. Its rule, as published on its substantial damage page: “Whether your home is determined as Substantially Damaged or not, all improvements are subject to the 49% structure value rule.” When you apply for the permit, you and your contractor sign a form attesting that the permit describes all of the work. So the time to settle the whole scope is before you apply, not halfway through the job.
Two federal definitions, and the sentence that joins them
Both terms come from the federal flood insurance regulations, 44 CFR 59.1.
Substantial damage is damage of any origin where “the cost of restoring the structure to its before damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.”
Substantial improvement is “any reconstruction, rehabilitation, addition, or other improvement of a structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the ‘start of construction’ of the improvement.”
They read like opposites. One is about what happened to the house; the other is about what you choose to do to it. The sentence that joins them sits inside the second definition: substantial improvement “includes structures which have incurred ‘substantial damage’, regardless of the actual repair work performed.”
FEMA’s guidance for local officials, Answers to Questions About Substantially Improved/Substantially Damaged Buildings (FEMA P-213, August 2018), puts it plainly: “when the NFIP regulations refer to substantial improvement, repair of substantial damage is included.” It also says that for either determination, “the calculation is the same.”
They are still two determinations. One measures the cost of putting the house back the way it was; the other measures the cost of the work you propose. But they run on the same arithmetic, and on a damaged house the work you propose usually includes both.
Fifty percent is the federal figure. Local governments can adopt a stricter one, and several in Pinellas have. The city-by-city page says which.
In unincorporated Pinellas, repairs and improvements count against 49%
Pinellas County manages substantial damage assessments for unincorporated areas. If you live inside a city, the county’s own page tells you to contact your city, and the city-by-city page lists each one’s figure and who to call.
For unincorporated Pinellas, the county’s substantial damage page (last updated July 9, 2026) sets the line at 49%. If the cost to repair is “49% or more of its value without the land,” the home is substantially damaged and cannot be repaired without being brought into compliance with current floodplain codes, “e.g. elevating or replacing it.” The same page then applies that figure to all work: “Whether your home is determined as Substantially Damaged or not, all improvements are subject to the 49% structure value rule.”
FEMA gives local officials the same instruction at the federal figure. Its Substantial Damage Quick Guide, updated September 28, 2026, says to “Determine if repairing plus improving the damaged structure equals or exceeds 50% of the structure’s pre-damage value.”
In practice, a house whose damage is under the line can still cross it once a new kitchen, an addition or a reworked layout goes onto the same job.
What the county’s disclosure form asks you and your contractor to sign
Linked from the county’s substantial damage page is a one-page Floodplain Substantial Improvement Disclosure Form. It is “for structures in the floodplain,” and the county says you “will be required to submit this form upon submitting a building permit plan for an improvement or damage repair.” The structure owner and the contractor both complete it.
The form asks for the jurisdiction, the substantial improvement limit, the total cost of the improvement and the structure’s market value. The limit has three boxes, 49%, 50% and “Other,” a reminder on the form itself that the figure is not the same everywhere.
Then come the statements you sign. In the form’s words:
- “phasing improvements to the building is not permitted”;
- the description in the permit application “is all the work that will be done, including all improvements, rehabilitation, remodeling, repairs, additions, and any other form of improvement”;
- “unforeseen repairs (i.e., termite damage, or deteriorated wood) may trigger the requirement for total compliance with flood regulations of this structure”;
- the total scope and cost “shall not be increased in any manner without the express written consent of Pinellas County Building and Development Review Services”;
- you are “subject to enforcement action and/or fines” if an inspection finds repairs or improvements that were not in the description and cost estimate the permit was issued on.
Read together, that is the whole procedure on one page. The remodel you add while repairing goes on the same form and into the same number. So does rot found behind the drywall. And the job cannot quietly grow after the permit issues.
This is the form as the county linked it on October 23, 2026. If the county reissues it, the current version will be on the county’s page.
What counts toward the number
The county lists “some examples of the costs to include when estimating repairs and improvements.” They are examples, not a complete list:
- Materials and labor cost (including donated or discounted materials and owner-or volunteer-completed labor)
- Structural elements
- Demolition and debris disposal
- Contractor overhead or profit
- Utility and service equipment
- Elevation or floodproofing
- Site preparations
- Costs associated with complying with regulations or code requirements
- Interior and exterior finishes
Costs are “based on average commercial rates for labor and materials,” so doing the work yourself, or getting materials free, does not take them out of the number.
Doing less now does not shrink it either. FEMA P-213 says that even if an owner proposes to do less than all of the work needed to repair the damage, “the determination must be made on the cost to fully repair and restore the structure to its pre-damage condition.”
What the number is measured against
The other half of the ratio is the structure’s market value. The county defines it as “the value of the building and structures, excluding the land and other improvements on the parcel.”
It sets two ways to establish that value. One is Actual Cash Value, “like-kind replacement cost depreciated for age, wear and tear, neglect and quality of construction,” from a qualified independent appraiser following the county’s appraisal checklist. The other is the Property Appraiser’s “Just Value” of the structure, “adjusted to approximate market value.”
It is not what the house and lot would sell for, and it is not the land. The county’s page explains where to find the Property Appraiser’s figure and what to do if you think it is too low. A higher, documented structure value raises the line for the same scope of work.
Two federal exclusions, and who decides whether they apply here
The federal definition of substantial improvement leaves out two kinds of work. One is correcting existing code violations “identified by the local code enforcement official” that are “the minimum necessary to assure safe living conditions.” The other is an alteration to a historic structure that will not stop it being designated as historic.
Those are federal terms. Whether either applies to your project is your building department’s call. Ask before you count on it.
Condo and townhouse buildings, and work spread over time
Everything above is about one structure and one permit. For condominium and townhouse buildings that were not substantially damaged, the county counts differently, adding open permits and recent work across the building. The city-by-city page explains that rule.
Read as written, the form’s line that “phasing improvements to the building is not permitted” is about one permit’s scope: the description has to cover all of the work. For anything about adding up separate projects over time, see the lookback section of the city-by-city page.
Before you apply
If the whole job, everything included, is well under the line, the form is paperwork. If it is close, the scope decisions are worth making before the application, with all of it written down: the repairs, the remodel you have been meaning to do, and some room for what opening the walls may find, which the form itself warns about.
Staying under is not automatically the right answer. Going over means bringing the house into compliance with current floodplain codes, and the county’s own examples are elevating or replacing it. Some owners choose that on purpose, because they would rather deal with it once. The three paths after a substantial damage determination and what lift-and-repair actually involves walk through what each route takes.
Either way, the answer for your house comes from your building department. The city-by-city page tells you which one that is.