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Port St. Lucie, FL Accessory Structures: ADU Rules (2026)

Some Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

ADU rules in Port St. Lucie, FL, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.

Key Facts

ADU in accessory-use list: Not listed for RE, RS-1 to RS-3
Unlisted accessory uses: Expressly prohibited (Sec. 158.217(C)(2))
Guest house: Special exception in RE, over one acre
Principal buildings per lot: One (Sec. 158.042)
Accessory use size cap: 20% of floor or ground area

ADU Eligibility Quick-Check

An Accessory Dwelling Unit (ADU) is a smaller, independent living unit on the same lot as a single-family home: converted garages, detached cottages, basement or attic conversions, and attached additions all qualify. Most states have streamlined ADU permitting since 2020, but local rules still control size, height, and setback.

Is your lot zoned single-family or multi-family residential?
Does your lot have at least 1,200 sq ft of buildable space?
Is your existing home owner-occupied (in most states this is not required, but some require it for ADU permits)?
Will the ADU stay under your state's size cap (commonly 850-1,200 sq ft for detached)?
Can you provide one off-street parking space (waived in many states within 0.5 mi of transit)?

If you answered 'yes' to most of these, you likely qualify in Florida under recent ADU streamlining laws. The Port St. Lucie, FL rules below cover local size, height, and setback requirements.

Summary

Port St. Lucie defines an accessory dwelling unit but does not list one among the accessory uses allowed in single-family districts, and Sec. 158.217(C)(2) prohibits every accessory use it does not list. Guest houses are treated separately.

(2) 'Accessory dwelling unit' means an ancillary or secondary living unit, that has a separate kitchen, bathroom, and sleeping area, existing either within the same structure, or on the same lot, as the primary dwelling unit. (3) A local government may adopt an ordinance to allow accessory dwelling units in any area zoned for single-family residential use. The ordinance must provide that any accessory dwelling unit allowed under the ordinance shall apply toward satisfying the affordable housing component of the housing element in the local government's comprehensive plan under s. 163.3177(6)(f).

Source: City of Port St. Lucie Code of Ordinances (Municode)View official code

Full Breakdown

The code defines an accessory dwelling unit as a secondary housing unit on the same parcel as a primary dwelling, with its own bathroom, kitchen and separate external entrance, and says guest houses are not ADUs. Sec. 158.217(C)(2) then lists the accessory uses allowed in the RE and RS-1 through RS-3 districts, pools, garages, sheds, fences, gazebos and similar structures, and states that all other accessory uses are prohibited. An ADU is not on that list. Sec. 158.042 separately allows no more than one principal building, structure or use per lot in single-family districts.

Violations & Fines

An unpermitted second dwelling unit is enforced through Chapter 37, where Sec. 37.09 allows fines up to $1,000 per day for a first violation and $5,000 per day for a repeat violation.

Frequently Asked Questions

Can I build an accessory dwelling unit (ADU) on my single-family lot in Port St. Lucie?

Not as a listed accessory use. Sec. 158.217(C)(2) sets out the accessory uses allowed in RE and RS-1 through RS-3 and states that all other accessory uses are prohibited; an ADU is not among them.

What is the difference between a guest house and an ADU?

The code's definitions separate them. An ADU has its own bathroom, kitchen and independent external entrance. A guest house is for intermittent or temporary occupancy by a nonpaying guest and cannot be rented or used as a separate dwelling.

Can I build a guest house instead?

In the RE estate residential district, a guest house on a lot exceeding one acre is a special exception use, permitted only after review and specific approval by the City Council (Sec. 158.071(C)).

Sources & Official References

Other rules in Port St. Lucie

Shed & Carport RulesSome Restrictions Garage ConversionsSome Restrictions Tiny HomesHeavy Restrictions Parking Rules: Driveway RulesSome Restrictions Parking Rules: Abandoned VehiclesSome Restrictions Fence Regulations: Neighbor Fence RulesSome Restrictions Fence Regulations: Retaining WallsSome Restrictions Animal Ordinances: MicrochippingLight Restrictions Animal Ordinances: Cat RulesSome Restrictions

All Port St. Lucie rules

How Port St. Lucie compares: Easiest Cities to Build an ADU·Florida rules heatmap·Compare Port St. Lucie to another location·View the Florida accessory structures overview

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