In-Law Suite and ADU Rules Across Hillsborough, Pinellas and Pasco
It depends on which city or county governs your address, and the differences are large: Largo allows no accessory dwelling in a flood hazard zone, New Port Richey allows only an apartment inside the house, and Tampa allows a full accessory dwelling unit in just four areas. Find your jurisdiction first, because size, owner occupancy and whether the unit can stand apart from the house all follow from it.
Start with the government that governs your address
The single most useful thing to know is which government writes the rules for your lot, because Tampa Bay has many rulebooks, not one. Several of the most familiar place names are not cities at all. The Census Bureau classifies Brandon, Riverview, Sun City Center, Apollo Beach, Lutz, Palm Harbor, Wesley Chapel and Land O' Lakes as census designated places, named communities with no municipal government of their own, so a home there answers to the county. Tampa, St. Petersburg, Clearwater, Largo, New Port Richey, Zephyrhills and the other incorporated cities each set their own rules.
Unincorporated Hillsborough: Brandon, Riverview, Lutz and Sun City Center
Hillsborough County allows one accessory dwelling per lot, attached or detached, with up to 900 square feet of living space, on a lot of at least 7,000 square feet, with the main home owner occupied. Storage and laundry count toward the 900. A variance to go larger is possible only on lots of at least 14,520 square feet, and then only to 1,200 square feet or a quarter of the main home, whichever is less. One rule surprises families: a detached structure, or part of the house that cannot be reached from inside, that is not a permitted accessory dwelling may not be used for sleeping at all, even by a visiting guest.
Tampa, Temple Terrace and Plant City
Inside Tampa, a full accessory dwelling unit is allowed only in Seminole Heights, around Lowry Park and in the East Tampa and Tampa Heights overlays, capped at 950 square feet of living space, with the owner living on the property and one parking space per unit. Elsewhere in the city a unit for a parent follows the Extended Family Residence rules in our kitchen guide. Plant City allows a garage apartment on an owner-occupied R-1 lot of at least 6,000 square feet, up to 600 square feet of livable space, and above a detached garage only where the main house has two or more stories. In Temple Terrace, any addition needs a permit from the city's Building Department before work begins, and additions are not processed by email.
St. Petersburg and Clearwater
St. Petersburg caps an accessory dwelling at 800 square feet, with everything under roof no more than 67 percent of the main home, and sets minimum lot sizes by district: 4,500 square feet in NT districts, and larger or specially placed lots in NS districts. It does not require the owner to live on the property, and it allows separate meters and a separate address. Clearwater treats an accessory unit as a Level One flexible standard use in its low and low-medium density districts, up to 750 square feet or half the main home, whichever is less, with the entrance to an attached unit kept out of view from the street.
Largo, Pinellas Park, Seminole and Safety Harbor
Largo is the one to check first if the house is near water: its code does not permit accessory dwellings in the Coastal High Hazard Area or the Special Flood Hazard Area at all, and elsewhere caps them at 800 square feet or half the main home, with a notarized affidavit on affordable rent if the unit is ever rented. Pinellas Park allows one per single-family lot at up to 600 square feet of air-conditioned space, with an extra parking space and a recorded deed restriction against selling it separately. Seminole allows up to 750 square feet in every residential district. Safety Harbor allows 300 to 800 square feet, no more than half the main home, for two occupants at most.
Dunedin, Tarpon Springs and Palm Harbor
Dunedin's code states its purpose outright: small dwellings to meet the housing needs of elderly persons of modest income. It allows one unit of up to 800 square feet on any single-family lot, attached or detached, with no separate metered utility, up to three occupants of whom two are immediate family, and a recorded affidavit that the owner lives in one of the two homes as a homestead. Tarpon Springs allows up to 600 square feet or 20 percent of the main home, whichever is greater, with the main home owner occupied. In unincorporated Pinellas, including Palm Harbor, the limit is 1,000 square feet, or 750 in flood hazard areas, and development review fees are waived.
Pasco County, New Port Richey and Zephyrhills
Pasco County allows accessory dwellings in districts that allow single-family homes, up to 1,200 square feet and smaller than the main home, and says they are intended in part to house extended families. A unit under 500 square feet pays no impact fees other than school fees, and one over 900 pays the full single-family rate. A converted garage must lose its garage door, and a home on septic and well needs Health Department approval. New Port Richey is stricter: only an apartment inside the house, no more than a quarter of its floor area, with no variances. Zephyrhills applies its rules to a defined core area, requires 375 to 575 square feet and a kitchen, and requires the owner to hold a homestead exemption.
Covenants, and what to bring when you ask
Zoning is not the only rulebook. Pasco's own code warns that a neighborhood's restrictive covenants may prohibit an accessory dwelling even where the county allows one, and the deed restrictions on any home are worth reading for the same reason. If the answer for your address is no, it is better to know now, because a bedroom and bath joined to the house may still be possible where a separate unit is not. Send us the address, who the space is for and whether it needs a kitchen, and we will set out which rules apply before you are connected with a licensed contractor to price it.
Sources used in this guide
The Census Bureau defines census designated places as settled concentrations of population identifiable by name but not legally incorporated under state law; the 2020 Florida place list classifies Palm Harbor, Brandon, Riverview, Sun City Center, Apollo Beach, Lutz, Wesley Chapel and Land O' Lakes as census designated places.
Source: U.S. Census Bureau, accessed 2026-09-23
The 2020 Census place list classifies Tampa, Temple Terrace and Plant City (Hillsborough), St. Petersburg, Clearwater, Largo, Pinellas Park, Dunedin, Seminole, Safety Harbor, Tarpon Springs and Oldsmar (Pinellas), and New Port Richey and Zephyrhills (Pasco) as incorporated places.
Source: U.S. Census Bureau, accessed 2026-09-23
Unincorporated Hillsborough County's Land Development Code (Sec. 6.11.02) limits accessory dwelling living space to 900 square feet, requires a lot of at least 7,000 square feet and an owner-occupied principal home, allows attached or detached units, and allows one per lot. A variance to go larger is available only on lots of at least 14,520 square feet, and then to no more than 1,200 square feet or 25 percent of the main home's living space, whichever is less; living space includes storage and laundry.
Source: Hillsborough County (Municode), accessed 2026-09-23
Hillsborough County's code says any detached structure, or any part of a home that cannot be reached internally, that does not meet the accessory dwelling requirements may not be used for independent living quarters or for sleeping, including guest visits, at any time.
Source: Hillsborough County (Municode), accessed 2026-09-23
The City of Tampa allows accessory dwelling units only in Seminole Heights, the area around Lowry Park, the East Tampa Overlay and the Tampa Heights Overlay; everywhere else in the city a second unit may only be created for a family member as an Extended Family Residence.
Source: City of Tampa, accessed 2026-09-23
Tampa's ADU standards (Sec. 27-132) cap an ADU at 950 square feet of living space, require the property owner to reside on the property, limit unrelated occupants to two, permit a separate utility meter, and require one parking space per unit.
Source: City of Tampa, accessed 2026-09-23
Plant City's R-1 district allows a garage apartment on an owner-occupied single-family lot of at least 6,000 square feet, capped at 600 square feet of livable space and 800 gross square feet, one per lot, placed beside or behind the main house, and above a detached garage only where the main house has two or more stories.
Source: City of Plant City (Municode), accessed 2026-09-23
The City of Temple Terrace requires any owner, agent or contractor who will construct, enlarge or alter a building to obtain a permit from the Temple Terrace Building Department before work begins; applications that need zoning or plan review, such as additions, are not processed by email.
Source: City of Temple Terrace, accessed 2026-09-23
St. Petersburg (Sec. 16.50.010, amended 7-10-2025) caps an ADU at 800 square feet of gross floor area, with all areas under roof no more than 67 percent of the principal dwelling's floor area. A new ADU needs a lot of at least 4,500 square feet in NT districts, and in NS districts a lot of at least 10,000 square feet, an alley lot of at least 4,500 square feet, or a qualifying corner lot.
Source: City of St. Petersburg (Municode), accessed 2026-09-23
St. Petersburg does not require the main unit to be owner occupied or homesteaded for an ADU; if both units are rented, a Business Tax Certificate is required. Separate meters and a separate address are allowed, and rentals under 30 days are limited to three times in 365 days.
Source: City of St. Petersburg, accessed 2026-09-23
Clearwater treats an accessory dwelling unit as a Level One flexible standard use in its low and low-medium density residential districts, capped at 750 square feet or 50 percent of the principal dwelling's gross floor area, whichever is less, one per parcel with conforming density, with entrances to attached units not visible from the street.
Source: City of Clearwater (Municode), accessed 2026-09-23
Largo's Comprehensive Development Code (Sec. 16.14, Ord. 2025-01) does not permit ADUs in the Coastal High Hazard Area or the Special Flood Hazard Area, caps an ADU at 800 square feet or 50 percent of the principal home's living area, whichever is less, requires either the main home or the ADU to be owner-occupied, and requires a notarized affidavit that the unit, if rented, will be rented only at an affordable rate as defined in F.S. 163.31771.
Source: City of Largo (Municode), accessed 2026-09-23
Pinellas Park permits one ADU on any single-family lot but caps its air-conditioned area at 600 square feet, requires one additional off-street parking space, and requires a recorded deed restriction prohibiting sale of the ADU separately from the main house before the certificate of occupancy (Sec. 18-1530.28).
Source: City of Pinellas Park (Municode), accessed 2026-09-23
Seminole permits accessory apartments, garage apartments and guest houses of up to 750 square feet on single-family lots in all residential districts, allows separate utility meters, requires one of the units to be owner-occupied, and exempts ADUs from district density and parking requirements (Sec. 70-891).
Source: City of Seminole (Municode), accessed 2026-09-23
Safety Harbor permits ADUs in all single-family districts at 300 to 800 square feet, not more than 50 percent of the principal home, with no more than two occupants, owner occupancy shown by Pinellas homestead status, and detached units outside the E-1 district only on corner lots or lots with improved alley access (Sec. 36.01).
Source: City of Safety Harbor (Municode), accessed 2026-09-23
Dunedin's ADU code (Sec. 107-21) states its purpose as small dwellings to meet the housing needs of elderly persons of modest income. It permits one ADU of up to 800 square feet on any single-family lot, attached or detached, prohibits a separate metered utility connection, limits occupants to three (two of immediate family relation), and requires the owner to occupy either unit as a homesteaded residence under a recorded notarized affidavit.
Source: City of Dunedin (Municode), accessed 2026-09-23
Tarpon Springs defines an accessory dwelling unit as up to 600 square feet or 20 percent of the primary structure's floor area, whichever is greater, one per parcel, with the primary dwelling owner-occupied, no separate metered utility connection, and a recorded restrictive covenant.
Source: City of Tarpon Springs (Municode), accessed 2026-09-23
Unincorporated Pinellas County (Sec. 138-3210) allows accessory apartments, garage apartments and guest houses up to 1,000 square feet, or 750 square feet in the Coastal Storm Area or flood hazard areas, counting connected unconditioned space such as a garage. The unit needs a separate entrance, sleeping quarters, a bathroom and a full kitchen with sink, cooking unit and refrigerator; either the main home or the ADU must be owner-occupied, separate meters may be permitted, and development review fees are waived.
Source: Pinellas County (Municode), accessed 2026-09-23
Pasco County's Land Development Code (Sec. 530.24, Ord. 25-22, April 2025) allows ADUs in zoning districts that allow single-family homes, up to 1,200 square feet of living space and smaller than the principal home, and it states that ADUs are intended in part to provide housing for extended families.
Source: Pasco County (Municode), accessed 2026-09-23
Pasco County charges no impact fees other than school for an ADU under 500 square feet; ADUs from 500 to 900 square feet pay reduced mobility and library rates, and ADUs over 900 square feet pay full single-family impact fees.
Source: Pasco County (Municode), accessed 2026-09-23
Pasco's ADU section warns that individual restrictive covenants may prohibit ADUs, requires a garage converted to an ADU to have the garage door removed and the opening closed, and requires Health Department approval where the home relies on septic and well.
Source: Pasco County (Municode), accessed 2026-09-23
New Port Richey's Land Development Code allows one accessory apartment in a single-family home only within the principal structure (a breezeway or roofed passage does not count), capped at 25 percent of the home's gross floor area, with no variances allowed to accommodate it.
Source: City of New Port Richey (Municode), accessed 2026-09-23
Zephyrhills applies its ADU rules to a defined core area between C Avenue and North Avenue and between 1st Street and 20th Street, with other properties reviewed case by case; an ADU must have 375 to 575 square feet of living area and a kitchen, and the owner must hold a homestead exemption on the property.
Source: City of Zephyrhills (Municode), accessed 2026-09-23
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