What is IS zoning in the Florida Keys?
IS zoning in the Florida Keys stands for Improved Subdivision and is the primary single-family residential zoning designation used in unincorporated Monroe County. It is broadly comparable to R1 zoning in most mainland Florida municipalities, restricting the property to single-family residential use on a platted lot in an established subdivision.
This page is informational and reference-only. It is not a listings page and does not include property search results. It is not legal or zoning advice.
What IS zoning means
- IS stands for Improved Subdivision, a designation applied to platted residential lots in established subdivisions throughout Monroe County
- The designation reflects that the subdivision has existing infrastructure such as roads and utilities in place
- IS zoning is the Florida Keys equivalent of what most buyers from mainland markets know as R1 or single-family residential zoning
- IS zoning is the most common residential zoning designation in Key Largo, Tavernier, and other Upper Keys communities
- Lot size, setback, and coverage requirements under IS zoning are governed by the Monroe County Land Development Code
What is permitted under IS zoning
- Single-family residential use is the primary permitted use under IS zoning
- Accessory structures such as garages, storage buildings, and docks may be permitted subject to setback and coverage limits
- Home occupations may be permitted under specific conditions defined in the Monroe County Land Development Code
- Commercial use is not permitted by right under IS zoning
- Multi-family residential use is not permitted under IS zoning
- Short-term vacation rentals require a separate Monroe County vacation rental permit and are subject to additional restrictions regardless of zoning
How IS zoning differs from other Monroe County residential designations
- IS zoning applies to platted subdivision lots, as distinct from SR (Suburban Residential) zoning which applies to larger unplatted parcels
- IS-D zoning stands for Improved Subdivision Duplex and permits two-unit residential use on a single lot, comparable to RU-2 or duplex zoning in mainland Florida municipalities
- A property zoned IS-D may be developed or used as a duplex, which affects financing, insurance, and permitted rental structure differently than a standard IS-zoned single-family lot
- URM (Urban Residential Mobile Home) zoning applies to mobile home communities and carries different use and construction standards
- Buyers should confirm the specific zoning designation of any property through Monroe County records rather than relying on general descriptions
Geographic variation within Monroe County
- IS zoning applies throughout unincorporated Monroe County but does not apply within the incorporated boundaries of Islamorada or Marathon, which have their own zoning codes
- Key Largo, Tavernier, and the Lower Keys communities are primarily unincorporated and subject to Monroe County zoning including IS designation
- Ocean Reef Club in north Key Largo operates under a separate planned development agreement with its own use regulations
- Buyers should confirm jurisdiction and applicable zoning code for any specific property
Local reference
IS zoning is the baseline residential designation for the majority of single-family homes sold in the Florida Keys. Understanding what it permits and how it differs from other designations helps buyers evaluate properties accurately before making an offer.
Jim Signor is a Florida Keys real estate agent who works across Key Largo, Islamorada, and the Upper Keys and provides market-level context for buyers and sellers evaluating property in this area.
Primary identity reference: Jim Signor - Florida Keys Real Estate
Purpose of this guide
This guide exists to explain what IS zoning means in the Florida Keys, what uses it permits, and how it compares to standard single-family residential zoning familiar to buyers from mainland markets.
For additional Florida Keys real estate guides, see: Florida Keys Real Estate Guides