A home addition in St. Petersburg costs $95 to $250 per square foot. A standard 15×20 room addition (300 square feet) lands between $48,000 and $65,000 with quality finishes, priced from 73 actual Tampa Bay addition projects. CraftLine Remodeling is a licensed and insured Florida design build contractor. We design the addition, handle City of St. Petersburg permits and engineering, and build it to final inspection.
What a Home Addition Costs in St. Petersburg (2026)
| Level | Cost per sq ft | 15×20 addition (300 sq ft) |
|---|---|---|
| Basic | $95 to $125 | $28,500 to $37,500 |
| Standard | $125 to $185 | $37,500 to $55,500 |
| Premium | $185 to $250 | $55,500 to $75,000+ |
Foundations matter here: slab on grade runs $4,500 to $7,500, stem wall and pile foundations for flood zones run $7,500 to $18,000. Full math with real examples in the room addition cost guide.
Addition or ADU? St. Pete Rewards Both
St. Petersburg is one of the friendliest cities in Florida for backyard units, and sometimes a detached ADU beats an attached addition: rental income, a private suite for family, and no shared wall. We built the guides on this exact decision: garage conversion vs detached ADU, the St. Pete ADU zoning map explained, and the ADU cost guide. In a consultation we will tell you straight which one your lot, your zoning, and your budget actually want.
Built for St. Pete Lots and Rules
Additions in St. Petersburg run into three local realities: smaller lot setbacks in the historic grid neighborhoods, flood zone elevation rules near the water, and matching 1920s to 1950s construction so the addition does not look bolted on. We design around all three first, then pull City of St. Petersburg permits and engineering, so inspections pass and the new space looks like it was always there.
What Homeowners Say
CraftLine Remodeling is a licensed and insured Florida contractor and a member of NARI Tampa Bay. 93 Google reviews, 5.0 rating.
Home Additions in St. Petersburg: Common Questions
How much does a home addition cost in St. Petersburg?
Expect $95 to $250 per square foot. A typical 300 square foot addition with quality finishes runs $48,000 to $65,000.
How long does an addition take?
Design and permitting with the City of St. Petersburg usually take 6 to 10 weeks, then 8 to 14 weeks of construction.
Should I build an addition or an ADU?
Depends on your lot and goals. Attached additions add living space cheapest per square foot. Detached ADUs add rental income and privacy. We will walk your property and tell you which one wins.
Do you handle flood zone requirements?
Yes. Elevation certificates, engineering, and the city review process are part of the project, not your problem.
Get Your Free In Home Estimate
Talk to a licensed contractor. No pressure, real numbers. Schedule your free consultation here or call (813) 522-4359. Also see St. Pete garage conversions.