The City of Key West, Florida

The Southernmost City in the Continental United States


Mobile Homes

 Mobile Homes in Flood Zones


Q.  Can I build an addition onto my mobile home?

A.  Probably not. Mobile homes manufactured after June 15, 1976 arrived pre-certified by the state and federal governments, so they weren't subject to local building inspections; but their foundations and installation are subject to local permitting and inspections.

The federal government's authority over mobile homes expires when the warranty expires, or the unit ceases to be classified as a mobile home.  Building onto a unit will cause it to lose it's mobile home designation, making it subject to the full range of building codes, just as if it were a built home.

Cutting into the walls to enlarge a room, attaching an addition or anything else that prevents a mobile home from transiting the highways, makes such a structure a building.  As a building, rules that govern mobile homes no longer apply.

Prior to 2013, mobile homes could be installed below minimum flood levels (known as "Base Flood Elevation or BFE), so long as the frame was at least 36" above the grade.  When a mobile home is reclassified as a building, it must be elevated to BFE plus one-foot; which is usually much higher than most mobile homes were installed.

All the other building codes would then apply as well, requiring: anchoring, use of flood resistant materials, flood venting, strapping... etc.  Thus, an addition to what had been a mobile home would require the entire structure be elevated to the proper height above flood levels.

Q.  I want to install a new mobile home, or relocate one to a different site within a regulated flood zone.  How high does it need to be?

A.  The bottom of the frame must be at least to the Base Flood Elevation (BFE) for site upon which it will be installed.  (See How to Read Flood Maps)


Q.  Can I use regular home building materials to repair my mobile home?

A.  If you make repairs to a mobile home using non-original mobile home materials, or the work is performed by a non-certified mobile home engineer, you risk this structure losing its mobile home status.  It would then become a building, and would need to adhere to all the building codes, which usually require buildings be elevated higher that mobile homes.


Q.  What about building an unattached deck or shelter next to my mobile home?

A.  An outside deck, with a shelter, is permissible, so long as they aren't attached to the mobile home, and the home can be moved freely without obstruction.  The Building Department will usually require engineered drawings to show the deck's independence from the mobile home and structural integrity.  

Standard building and planning codes would apply to the accessory construction. Such areas would likely not be usable for anything other than storage, parking and access to and from the mobile home.







Contact Us

Scott Fraser,
FEMA Coordinator/Floodplain Administrator
Building Department
1300 White St
Key West, FL 33040
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  • Assistant: (305) 809-3810
  • Staff Directory
  • Monday - Friday; 9:00 a.m. - 5:00 p.m.

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