How do I know if I’m allowed to build an ADU on my property? How big can it be?

ADU requirements vary by city and jurisdiction. Your property’s zoning, lot size, setbacks, and other local regulations can determine whether an ADU is allowed and what size it can be. Maximum ADU size requirements also vary by location. We can help you understand the regulations that apply to your property and determine what may be possible before moving forward with design and permitting.

How many rounds of revisions are included in the conceptual phase until I am satisfied with the design?

The number of revisions included during the conceptual design phase depends on the scope of your ADU project and the design package. We work closely with you to refine the design and make sure the layout, features, and overall concept align with your goals and property. Any revision limits or additional design services will be discussed with you upfront before moving forward.

Granny Flat Builder in Tampa Bay

A granny flat is not a real estate marketing word. In Tampa Bay, it is a zoning classification with a specific set of rules, and the families that get this right usually save themselves $60,000 to $100,000 in remodel mistakes and delays.

We design, permit, and build granny flats across St. Petersburg, Tampa, and the rest of Pinellas and Hillsborough counties. Most of our projects house a parent, a grown child back home after a divorce or a move, or a family member with medical needs who wanted privacy and wanted to stay close. The building itself is the easy part. The part we get paid to do well is the zoning, the lot analysis, and the permit set.

GET A FREE ESTIMATE

Who Calls Us for a Granny Flat

Adult children of an aging parent who does not want to move into assisted living. We have talked to more than a few families doing the math on $4,500 per month of memory care versus a $140,000 granny flat that pays itself off in roughly three years. Parents of a 20-something who needs a couple of years to reset after college, a divorce, or a career change, and would rather keep them close than pay a Tampa rental. Homeowners planning for a family member with a disability or chronic illness. These are the projects where accessibility design work at the start matters more than square footage. Empty nesters who want to live in the smaller unit themselves and put the kids in the main house when they visit. Cost comparison: Assisted living runs $3,500–$5,000/month ($420,000–$600,000 over 10 years). Memory care runs $5,500–$7,500/month ($660,000–$900,000 over 10 years). A granny flat amortized over 10 years runs $1,100–$1,700/month ($132,000–$204,000). Property value often increases by $80,000–$150,000 on top of that.

What We Build

A granny flat in Tampa Bay is almost always one of three forms: 1. Detached backyard granny flat: Its own small building in the back or side yard. Most privacy, highest cost, tends to appraise best. Typical size 500–950 sq ft. 2. Garage conversion granny flat: Your existing attached or detached garage reframed as a living unit. Lower cost, faster permit, but requires code-compliant egress, kitchen, bathroom, and HVAC. 3. Attached granny flat (addition): New square footage added to the main home with its own entrance, kitchen, and bathroom. Shares a wall with the primary. Often the best answer when the lot is tight. Every one of these has to meet Florida Building Code, 2023 Edition (8th). That means hurricane-rated openings, wind-uplift connectors, and a roof system rated for the wind zone your address sits in. In most of Pinellas County, that is Exposure C or D and a 140–150 mph ultimate design wind speed.

The Permit Path

1. Lot eligibility check: We pull your parcel data, confirm the zoning, check the ADU overlay if you are in Tampa, and verify lot size against the minimum for your zone. Fifteen minutes, free.

2. Setback and siting analysis: Every jurisdiction has front, side, and rear setbacks. We identify where on your lot the unit can actually sit.

3. Utility check: Existing electrical service capacity, sewer lateral sizing, and whether water service can support a second kitchen. Undersized electrical service is the single most common surprise on Pinellas County projects.

4. Permit drawings: Architectural, structural, mechanical, electrical, plumbing. All sealed. This is the stage where jurisdiction-specific rules actually get drawn into the plans.

5. Submittal and review: 60–120 days depending on jurisdiction and current backlog.

6. Build.

Frequently asked questions

Garage Conversion

Detached ADU

ADU Permitting

Granny Flat

Mother-in-law suite

ADU Feasibility Study

ADU size requirements vary by city and jurisdiction. The minimum or maximum size may depend on factors such as your property’s zoning, lot size, setbacks, and local regulations. Beyond what is allowed, the ideal ADU size depends on how you plan to use the space and the needs of your household. We can help you understand the applicable requirements and determine a practical size for your ADU before moving forward with design and permitting.