Thinking about closing in space under your stilt home in the Keys or buying a property that already has a downstairs enclosure? In the Florida Keys, that area sits in a flood zone, so the rules are strict and the stakes are high for insurance, permits, and closings. You deserve clear guidance you can use today. This guide breaks down what is allowed, what changed in 2025, and the steps to keep your sale or project on track. Let’s dive in.
What counts as a downstairs enclosure
A downstairs enclosure is any walled-in area below the required flood elevation under an elevated home. Under the National Flood Insurance Program, this space is not for living. It is limited to vehicle parking, building access, and limited storage. You can review FEMA’s definition of an enclosure and NFIP limits to understand the baseline rules set at the federal level here.
Monroe County enforces those limits through its local floodplain code. The county’s standards cover what you can use the space for, vent and opening requirements, and what finishes and utilities are allowed below the Base Flood Elevation. You can read the county’s floodplain code in Section 122-4 here.
What you can and cannot do
- Allowed: Parking, building access, and limited storage only. The county excludes household furnishings, large appliances, and other items that are vulnerable to saltwater or flood damage from “limited storage.” See local specifics in the county code here.
- Not allowed: Any habitable space below the required elevation. That means no bedrooms, no kitchens, and no temperature control for the enclosure.
- Finishes and utilities: Only basic, flood-resistant finishes are allowed. The space cannot be served by utilities as living area. Limited electrical may be approved only if specifically permitted. Review details in Section 122-4 here.
- Openings in AE/A zones: Enclosures below BFE need flood vents that automatically equalize water. Monroe County requires at least 1 square inch of net opening per square foot of enclosed area, at least two openings on separate walls, and the bottom of each opening no higher than 1 foot above grade. A design professional can certify alternate designs. FEMA’s technical guidance on openings is available here.
- V zones and breakaway walls: In coastal high hazard areas, the space below the lowest floor is generally open. If you use walls, they must be breakaway and non-structural, engineered to fail under flood and wave loads without damaging the home above. See FEMA’s breakaway wall guidance in TB-9 here and City of Key West notes here.
City vs county rules
Rules can differ between unincorporated Monroe County and municipalities like the City of Key West. Always confirm the property’s jurisdiction before you plan any work or close on a sale. Start with the county’s Building Requirements overview here and check city pages if the property is inside city limits, including Key West’s breakaway wall guidance here.
The April 2025 update
On April 4, 2025, FEMA supported Monroe County’s effort to remove the long-standing 299 square foot cap for storage enclosures below BFE and to change the transfer-of-ownership inspection rules. This is approval in principle. The county still must adopt and implement code amendments before anything changes in practice. The expected timeline is several months, and NFIP limits on habitable use below BFE still apply. You can review the announcement summary here.
Until the county’s ordinance is formally amended and effective, you must follow the current code and processes. When permitted expansions are allowed, expect recorded non-conversion agreements that bind future owners to keep the space non-habitable.
Buyer and seller checklist
Use this quick path to avoid surprises during escrow or construction.
- Confirm jurisdiction
- Check if the property is in unincorporated Monroe County or within a city. Start with the county’s Building Requirements page here.
- Find the flood zone and BFE
- Pull the effective Flood Insurance Rate Map and Base Flood Elevation from FEMA’s Map Service Center here. Save a FIRMette for your records.
- Collect the Elevation Certificate and permit history
- Ask for the Elevation Certificate and the enclosure’s permits from the Monroe County Building Department. The county’s overview and contact path is here. Treat any unpermitted work as a red flag.
- Check for recorded restrictions
- Look for any recorded non-conversion agreement tied to the enclosure. The April 2025 update references these for permitted expansions. See the context here.
- Plan your permit path
- All new work or alterations require county permits. Register and submit through the county’s permitting portal here. Expect multi-discipline plan reviews and inspections.
- Design to flood standards
- Follow FEMA TB-1 for openings and TB-9 for breakaway walls. Use flood-resistant materials and keep mechanicals above BFE. FEMA’s Technical Bulletins are collected here.
- Confirm transfer-of-ownership requirements
- Monroe County has historically required inspections at sale. Processes may change as code is amended, so verify current rules with the county. See background context here.
- Hire licensed pros
- Use licensed contractors and, if needed, a registered engineer or architect for certifications, especially in V zones. City of Key West guidance is here.
- Coordinate insurance and lender needs
- Lenders often require flood insurance in Special Flood Hazard Areas, and coverage for items in enclosures below BFE is limited under NFIP rules. FEMA’s enclosure context is summarized here.
- Document for closing
- Keep permits, Elevation Certificate, recorded agreements, and any inspection results on file. Title and underwriting often require them.
Risks of getting it wrong
- Insurance limits: NFIP coverage for enclosures below BFE is limited. Converting space to living area can jeopardize eligibility or raise premiums. See FEMA’s enclosure guidance here.
- Closing delays: Lenders and title may require proof of compliance, flood insurance, and any required inspections. Failing an enclosure review can delay or derail closing. Background on transfer-of-ownership processes is available here.
- Enforcement: Non-compliant enclosures can trigger code cases, fines, and required removal or mitigation. See Monroe County Code Compliance contacts here.
- Safety: Breakaway walls and vents protect the structure in surge and wave events. Making the space habitable undermines that safety intent.
Your next move
If you are evaluating a Keys property with a downstairs enclosure, take the time to confirm jurisdiction, flood zone and BFE, permits, and insurance impacts before you go under contract or start work. Align your design with FEMA bulletins and the Monroe County code, and keep a clean paper trail for closing. When you are ready for a strategic plan to buy or sell with confidence, connect with me at Eric Edward Exhibits to map out next steps.
FAQs
What is legally allowed in a downstairs enclosure in Monroe County?
- Parking, building access, and limited storage only, with no habitable use below the Base Flood Elevation per county code Section 122-4 and NFIP rules.
Do I need flood vents, and how many?
- Yes in AE/A zones; provide at least 1 square inch of net opening per square foot of enclosure with at least two openings on separate walls and openings no higher than 1 foot above grade, or have a design professional certify an alternative in line with FEMA TB-1.
Are breakaway walls allowed in V zones in the Keys?
- They may be used if designed as non-structural breakaway walls that fail under flood and wave loads without damaging the home above, typically requiring engineer or architect certification consistent with FEMA TB-9.
Will flood insurance cover items stored below BFE?
- NFIP coverage for enclosures below BFE is limited, and contents are restricted, so do not assume full coverage for stored items or any finishes in that space.
Do I still need a transfer-of-ownership inspection when selling?
- Monroe County historically required inspections at sale, and while FEMA supported changes in April 2025, you should confirm the current process with the county until new code language is formally adopted and in effect.
