ADU Builder in St. Petersburg, FL
Design-build accessory dwelling units built for long-term value, code compliance, and clean permitting — from detached backyard cottages to garage conversions.
Design-build accessory dwelling units built for long-term value, code compliance, and clean permitting — from detached backyard cottages to garage conversions.
ADUs for Homeowners Who Want More Space (and More Options)
If you’re considering building an ADU in St. Petersburg or anywhere in Pinellas County, it’s likely because you want flexibility without leaving the home and neighborhood you already love. Accessory dwelling units are ideal for multigenerational living, private guest suites, long-term rental income, or a dedicated home office that doesn’t feel temporary.
At Central Builders Group, we work with homeowners who are planning intentionally — not DIY projects, not quick add-ons, but thoughtfully designed structures built to last. If expanding your primary residence makes more sense for your goals, explore our Home Additions & Remodeling services.
Types of ADUs We Build
An accessory dwelling unit adds flexibility, privacy, and long-term value to your property. Whether detached, attached, or converted from an existing structure, an ADU creates an independent living space while preserving the integrity of your primary home.
Detached ADU
An ADU that is built as a separate structure on the property. The most popular form of ADU.
Attached ADU
An ADU that is built as an addition to the main property structure.
Garage Conversion ADU
An ADU that is built within the primary structure. Basements, attics, and garages are popular choices.
Investment Overview
How Much Does an ADU Cost in St. Petersburg?
ADU investment in St. Petersburg varies based on structure type, site conditions, and Pinellas County permitting requirements. Garage conversions typically start between $60,000 and $90,000. Attached ADUs generally range from $90,000 to $160,000. Detached ADUs represent the highest investment, typically $120,000 to $220,000+ depending on size, site conditions, and finish level.
| ADU Type | Typical Range | Key Cost Drivers |
|---|---|---|
| Garage Conversion ADU | $60,000 – $90,000 | Existing shell, utility tie-ins, finish level |
| Attached ADU | $90,000 – $160,000 | Structural integration, permits, utility work |
| Detached ADU | $120,000 – $220,000+ | Full foundation, framing, roofing, utilities |
Lowest Complexity
Garage Conversion ADU
$60,000 – $90,000
Conversion-based ADUs involve lower structural complexity since the shell already exists. Work focuses on interior buildout, insulation, HVAC, and utility tie-ins rather than new foundation or framing. Fastest path to a permitted, livable ADU on most Pinellas County lots.
Existing shell reduces complexity. Interior buildout, HVAC, and utility tie-ins only.
Moderate Complexity
Attached ADU
$90,000 – $160,000
Attached ADUs require integration with the main home, including utility tie-ins, structural reinforcement, and in some cases shared wall engineering. Permitting involves the primary structure, which adds review time in St. Petersburg’s building department process.
Structural integration with the main home. Utility tie-ins and shared permitting.
Highest Complexity
Detached ADU
$120,000 – $220,000+
Detached ADUs represent the highest investment tier, requiring new foundations, full utility routing, independent framing, roofing, and complete code compliance from the ground up. Coastal Florida construction standards and flood zone considerations influence engineering decisions and overall cost.
Full foundation, framing, roofing, and utilities. Coastal Florida standards apply.
What Drives ADU Cost
- Size and layout complexity
- Foundation type and site conditions
- Utility tie-ins — water, sewer, electric
- Finish level — rental-grade vs. premium
- Pinellas County permitting and impact fees
- Parking and zoning constraints
- Flood zone designation and FEMA compliance
Why Detached ADUs Cost More Than Conversions
Detached ADUs require complete structural systems: new foundation work, independent framing, full roofing assembly, and separate mechanical routing. Utility connections must be planned, permitted, and inspected as a standalone residential structure.
Coastal Florida construction standards influence engineering decisions throughout — wind resistance requirements, flood elevation rules, and Pinellas County plan review all add complexity that garage conversions do not carry.
While conversions modify existing space, detached ADUs function as standalone residences. That distinction drives both the structural planning and the overall investment.
Ranges reflect St. Petersburg and Pinellas County market conditions as of 2026. Coastal lots, flood zone properties, and historic districts may carry additional permitting and engineering costs.
Is an ADU the Right Option?
ADU vs Home Addition
An ADU creates a fully independent living space with its own entrance and functional separation from the primary home. A home addition expands the existing footprint of your residence but does not create a separate dwelling unit.
If your goal is integrated family space, an addition may be appropriate. If privacy and independent use matter more, an ADU provides greater flexibility. Explore expansion options here: Home additions contractor in St. Petersburg
Garage Conversion vs Detached ADU
Garage conversions can offer faster timelines and lower structural costs since the base structure already exists. However, they may be limited by layout, ceiling height, and parking considerations.
Detached ADUs offer more privacy, flexible design, and long-term asset value. If privacy, rental potential, or architectural freedom matter most, a detached build provides greater control.
ADU vs Buying a Bigger Home
Building an ADU allows you to stay rooted in your St. Petersburg neighborhood while gaining additional living space or income potential. Purchasing a larger home involves relocation costs, market uncertainty, and leaving a property you may already love.
An ADU turns your existing lot into a long-term asset while maintaining stability and lifestyle continuity.
ADU Zoning & Neighborhood Regulations in St. Petersburg
ADU construction in St. Petersburg requires careful review of zoning districts, lot size minimums, setback requirements, parking standards, and utility coordination. Flood zones and elevation rules may also influence structural planning. Before design begins, confirming local compliance prevents costly revisions. At Central Builders Group, we prioritize feasibility review first — because clarity upfront protects your investment later.
“They helped pick out the materials that would be both durable, good looking and in my price range. Even with a few small modifications the stayed on budget.“
“One of my biggest concerns going into this project was affordability and staying within a strict budget while not compromising on the quality of work. Central Builders Group understood my concerns and my vision and provided a detailed and transparent breakdown of costs while also remaining in constant contact with me throughout the entire project. “
“I wanted to renovate our office space. They provided a reasonable quote and were very professional. The job was done in a timely manner and I am very pleased with the results. I would highly recommend them.”
“We were ghosted by a contractor who had only laid the foundation. David came in and saved us and finished our garage + ADU build. He was super responsive and went above and beyond for us.“
“Their attention to detail (and patience with my pickiness) is unmatched. They are extremely knowledgable and professional. I can’t recommend them enough!“
ADU Builder Serving St. Petersburg and Pinellas County
Central Builders Group builds ADUs throughout St. Petersburg and Pinellas County — including Clearwater, Largo, Seminole, Pinellas Park, Dunedin, Safety Harbor, and St. Pete Beach. Each municipality has its own permitting process, and we handle the full scope from zoning verification through construction.
Communities We Serve
- St. Petersburg
- Clearwater
- Largo
- Seminole
- Pinellas Park
- Dunedin
- Safety Harbor
- St. Pete Beach
St. Petersburg ADU Rules
- Maximum size
- 800 sq ft maximum — no ADU may exceed this regardless of lot size
- Floor area ratio
- 67% rule — ADU floor area cannot exceed 67% of the principal dwelling
- Owner-occupancy
- Owner-occupancy required — main home or ADU must be owner-occupied
- Permit
- Permit required — all ADU types require Pinellas County plan review
Other Pinellas County municipalities have their own ADU frameworks. Eligibility is confirmed at the property level — every project starts with a zoning and feasibility review before any design work begins.
Plan Your ADU Project
Tell us about your property and how you plan to use your ADU.
Reach out now, we can start discussing options.
