Home › ADU Rules by County › Martin County
How big a backyard home (accessory dwelling unit) can be in Martin County, who can build one, and who to call to confirm — from the county's published rules.
Know your main home's size? Get the exact limit for your lot in seconds.
| ADUs allowed? | Yes |
|---|---|
| Maximum ADU size | 850 sq ft or 50% of the main home, whichever is less |
| Owner must live on site? | Not confirmed in our records |
| Manufactured home as an ADU? | Often allowed, subject to the county's ADU and zoning rules |
ADUs permitted subject to development standards. Must be on a concrete foundation/slab and located in the rear or side yard of the principal dwelling. Stuart, Jupiter Island, Sewall's Point and other municipalities set their own rules.
Source: Martin County LDR; verified Jul 2026.
Before You Build
ADU rules are set by each county and city — Florida law (Fla. Stat. 163.31771) lets local governments allow ADUs but doesn't require it — and they can change, so always confirm the current rule with Martin County before you build.
Confirm with Martin County: 772-288-5495 · zoning department website ↗
Zoning is set locally and changes often. Answers are guidance only, not a permit guarantee. Always confirm with the local building/zoning department before purchase.
Common Questions
Yes. ADUs permitted subject to development standards. Must be on a concrete foundation/slab and located in the rear or side yard of the principal dwelling. Stuart, Jupiter Island, Sewall's Point and other municipalities set their own rules.
850 sq ft or 50% of the main home, whichever is less.
Our records don't confirm an owner-occupancy requirement for Martin County — ask the county zoning department before you buy.
Often yes — many Florida counties allow a manufactured or modular home as an accessory dwelling unit, subject to Martin County's ADU size, lot, and setback rules. Confirm with the county for your parcel.
Keep Exploring
ADU rules for all 67 Florida counties · ADU-sized homes in our showroom
We'll confirm Martin County's rules for your property and help you pick a home that fits — free.
Start Here