Your home works — the location, the neighbors, the schools, the commute. The space doesn't. In St. Pete, adding on at $200-400 per square foot usually makes more financial sense than buying something new. Whether you're planning a master suite addition, an in-law suite or ADU, a garage conversion, or a detached secondary dwelling — in-house framing crew, open-book T&M pricing, and flood-zone code handled in-house.
St. Pete bungalows and 1950s–1970s slab-on-grade ranches were built for smaller families — two or three bedrooms under 1,200 sq ft. A 350–500 sq ft master suite addition (8–12 weeks of construction post-permit) gives room to grow without leaving the neighborhood.
The dining table stopped being a viable office a long time ago. A dedicated home office addition — or a detached garage conversion — gives you separation from household noise and a professional backdrop for calls.
As Jeremy Wharton, Revolution's owner, hears most often: “We have multiple half-million-dollar-plus remodels underway where it would have made more sense to sell and move, but they love their location so much that it only makes sense to expand there.”
An aging parent, an adult child moving back, or a frequent long-term guest — these situations need more than a pullout couch. An in-law suite (also called an accessory dwelling unit or ADU), a detached granny flat, or a garage conversion to a mother-in-law suite gives your family member privacy and independence while keeping them close. St. Pete's updated zoning allows accessory dwelling units on many residential lots — both attached in-law suites and detached secondary dwellings, depending on lot size and setbacks.
Design Phase
Architect coordination, structural engineer stamps for load-bearing changes, FIRM map / base flood elevation review, budget alignment through multiple pencil-sharpening rotations
3-6 months
Pre-Construction + Permitting
Sub bids locked, selections priced, St. Petersburg Building Department permit submitted (typically 3–6 weeks on a clean set for additions, longer if a Certificate of Appropriateness is required in a historic district) — 75% of line items confirmed before breaking ground
1-2 months
Construction + Move-In
Framing, ZIP sheathing, hurricane strap tie-in, rough framing inspection, electrical / plumbing rough-in inspections, insulation inspection, drywall, trim, and final inspection — then punch-list and walkthrough
~6 months
Design & Architecture
Architect coordinates layout, Pinellas County setback rules, lot coverage and impervious surface ratios, and structural engineer stamps for load-bearing changes
Pre-Construction Budget
Subs provide committed bids, selections coordinator prices finishes, our team issues weekly budget reports — 90-95% cost certainty by construction start
Permitting
St. Petersburg Building Department: building, electrical, plumbing, mechanical, roofing, and windows permits with FL Product Approval (NOA) numbers on every assembly
Field Walk & Handoff
Project manager, general superintendent, on-site super, and you walk the site together — zero ambiguity on scope
Foundation & Structural Tie-In
Epoxy and steel rebar for masonry, foundation underpinning where required, Simpson Strong-Tie hurricane straps and steel connections for wood framing. Our in-house W-2 carpenters handle this critical junction
Framing & MEP Rough-In
New walls with ZIP System sheathing, engineered trusses or stick-framed roof, then mechanical, electrical, and plumbing rough-in — each with its own mid-construction inspection before we close the walls
Envelope & Finishes
GAF Timberline shingles (or matching existing roof), PGT WinGuard impact windows, Hardie fiber-cement or LP SmartSide siding — often re-roofing the entire house for seamless integration. Then insulation inspection, drywall, trim, and final details
Inspections & Move-In
Final building, electrical, plumbing, and mechanical inspections, punch-list completion, and move-in preparation
Usually you can stay — at least during the structural phase. If the addition includes a kitchen remodel, plan for some time off-site. Rentals are expensive in St. Pete, so we keep clients in their homes as long as safely possible.
Per Jeremy: “Permits for additions cover everything like a new build — foundation, masonry, rebar, electrical, plumbing, roof, windows, doors, framing, insulation. Permitting takes two to five months in St. Pete.” Pinellas County setbacks (typically 6–7 ft side, 20–30 ft front, 25 ft rear) are plotted on the survey before design starts. Historic-district COA review adds 6–12 weeks to the front of that window. We pull every permit ourselves — building, electrical, plumbing, mechanical, roofing, windows — with FL Product Approval (NOA) numbers attached to every impact opening so plan review doesn’t stall.
| Addition Type | Cost per Sq Ft | Typical Total | Key Cost Driver |
|---|---|---|---|
| First-floor room (dry) | $200-250/sqft | $100,000-250,000 | Foundation extension, structural tie-in |
| First-floor room (wet) | $250-300/sqft | $150,000-350,000 | Plumbing, HVAC extension, fixtures |
| Second-story addition | $300-400+/sqft | $200,000-500,000+ | Structural reinforcement of existing walls/foundation |
| Garage conversion (dry) | ~$100/sqft | $100,000-200,000 | Existing shell reduces scope; common path for a garage-to-ADU or attached in-law suite conversion |
| Garage conversion (wet) | $150-250/sqft | $200,000-500,000 | Plumbing and kitchen drive cost up significantly — typical for full garage-to-ADU conversion or attached mother-in-law suite |
| ADU / accessory dwelling unit / detached granny flat / guest house | $250-400/sqft | $200,000-500,000+ | Detached secondary dwelling — fully self-contained structure, utilities, separate permitting |
| Florida room / sunroom | $80-400/sqft | $20,000-120,000+ | Glass-wall room type, impact glazing, HVAC integration |
St. Pete-area ranges based on 2025-2026 project data. Your actual cost depends on site conditions, finishes, and regulatory requirements.
For a detailed breakdown of every line item — including flood zone premiums, wet vs. dry room math, and real project examples — read our home addition cost guide.
For St. Petersburg-specific flood zone premiums, permit timelines, and AE/VE zone elevation guidance, see our St. Pete home addition page.
Jeremy Wharton, Owner, on St. Pete addition costs:
“Realistic cost per square foot in St. Pete is hard to pin down — depends on wet space. Example: a garage with two offices (no wet rooms) about 2,000 sq ft total cost $200,000; if it included a bath and kitchen it would be closer to $500,000. So roughly $200–300 per sq ft for first-floor additions and $300–400 plus for second floors.”
“When it makes more sense to add on versus move depends on how much people love their location, land cost, transaction costs, tax implications, and insurance. Often adding on at $400–500 per sq ft is cheaper than buying a new home at $700 per sq ft in the same neighborhood.”
These ranges anchor the cost table above. The wet-vs-dry difference, build-up-vs-out asymmetry, and add-on-vs-buy-new comparison are the three load-bearing decisions on every St. Pete addition project we estimate.
The terms get used interchangeably, and St. Pete zoning treats most of them as accessory dwelling units (ADUs). An attached in-law suite is built onto your main house with its own entry — usually the cheapest path. A garage conversion to an ADU (sometimes called a garage-to-granny-flat conversion) reuses the existing shell and runs $100-250/sqft. A detached secondary dwelling — the freestanding “granny flat” or detached mother-in-law suite — is the most expensive at $250-400/sqft because it needs its own foundation, utilities, and separate permitting. We pull the parcel's zoning before design to confirm which paths your lot allows.
Most St. Pete garage conversions follow a predictable scope. The shell is already there, so framing and roof are mostly a non-issue — the budget goes into bringing the space up to conditioned-living code. Six things drive the cost and timeline on every garage conversion we estimate:
For the full ADU-vs-detached-vs-garage cost comparison, zoning rules, and the four-types breakdown, see our garage conversion ADU guide.
“Realistic cost per square foot in St. Pete is hard to pin down — depends on wet space. Example: a garage with two offices (no wet rooms) about 2,000 sq ft total cost $200,000; if it included a bath and kitchen it would be closer to $500,000.”
— Jeremy Wharton, Owner, Revolution Contractors (anchor cost data point for St. Pete garage conversions)
Our Time & Materials approach puts you and your contractor on the same side: we bill for actual work performed, provide weekly budget reports comparing actuals to estimates, and give you access to every invoice. By construction start, 90-95% of costs are confirmed. When work goes faster than estimated, you save money — not the contractor. You see what we see — open-book billing, not summary reports.
Start with a conversation — not a sales pitch. We'll walk your property and give you honest feedback on what's possible.
Each guide goes deeper than we can on this page — real costs, real decisions, real St. Pete projects.
First-floor dry rooms run $200–250/sqft. Add a bathroom or kitchen, and you’re at $250–300. Second stories start at $300–400+ because your existing foundation wasn’t built for the load.
Full cost breakdown
12–18 months total: 3–6 months of design, 1–2 months of permitting, and roughly 6 months of construction. Here’s what happens in each phase and how to stay in your home during the build.
Phase-by-phase timeline
Adding on at $200–400/sqft vs. buying comparable homes at $700/sqft — the math usually favors staying. But the FEMA 50% Rule, lot constraints, or structural issues can flip the equation.
Decision framework
Licensing, insurance, communication style, contract terms — the checklist for evaluating home addition contractors in St. Petersburg before you sign anything.
Contractor checklist“Often adding on at $400-500 per sq ft is cheaper than buying a new home at $700 per sq ft in the same neighborhood.” — Jeremy Wharton, Owner
Not sure which path fits your situation? Read our full remodel, add on, or build new decision guide.
1920s-1930s bungalows and Mediterranean Revival homes. Small bedrooms, galley kitchens, single-bathroom homes that frequently need master suite additions. Historic district review adds 2-4 months to permitting.
Waterfront properties in the AE flood zone. Additions trigger the FEMA 50% rule review. Many homes are 3,000+ sqft but owners want larger master suites, home offices, or guest quarters.
1912-1945 bungalows on tight lots. Setback constraints limit expansion options, and tree preservation requirements are common. Creative design is essential.
1920s-1950s homes on approximately 6,500-sqft lots. Most can accommodate first-floor additions with room to spare.
Mid-century ranch homes on 60×120 lots. Best candidates for straightforward additions — Florida room integrations, master suite additions, and roof-to-ridge conversions with no flood zone or historic overlay holding scope back.
Redington, Treasure Island, Madeira Beach, Pass-a-Grille. Nearly all in VE or Coastal A flood zones. Additions here require full FEMA compliance from the start.
What sets us apart from other contractors in St. Petersburg.
20+ W-2 carpenters on payroll handle the critical structural tie-in, framing, ZIP sheathing, and Simpson Strong-Tie hurricane-strap work directly — no rotating subcontractors on the load-path. Framing crew and trim crew are separate, both in-house.
Open-book T&M billing with weekly budget reports — every invoice, every hour, every material receipt visible. By construction start, 90-95% of costs are confirmed. When work goes faster, you save money — not us.
$10-20 million in flood zone work across three hurricanes. We navigate FEMA’s 49% rule and elevation requirements on every coastal project.
Architect, project manager, superintendent, structural engineer, and selections coordinator working under one roof — a single point of accountability from first sketch through final inspection. Budget conversation starts during design — no sticker shock.
Late-career owners of $750K+ homes who have been through one fixed-bid renovation and rejected the change-order shell game. They want open-book T&M, weekly budget reports, and a single point of accountability — not a contractor padding every line item to cover risk. Most of our work is on Old Northeast, Snell Isle, and Shore Acres homes for owners who want to know where every dollar went.
Younger owners taking on their first major renovation. They want a process they can explain at a dinner party — and a builder whose name they can repeat to friends without hedging. Revolution runs an open-book pre-construction phase where we lock 75% of line items to firm pricing before demo. Weekly client meetings cover budget actuals against estimate. We pair clients with architects and designers we have worked with for years.
Capital-rich relocators from higher-cost markets — Northeast, California, Chicago — building legacy homes on Snell Isle, Tierra Verde, Shore Acres, or the downtown waterfront. They need a contractor who knows FEMA flood-zone math cold, not a paper contractor who walks away when the regs get hard. Revolution has $20M+ of flood-zone work going back to Hurricane Michael in 2018 and has cleared dozens of 49% rule substantial-improvement calculations across coastal Pinellas. With 20+ in-house W-2 carpenters, the schedule does not stall waiting on subs.
We build master suite additions, second-story additions, in-law suites and ADUs (accessory dwelling units — sometimes called granny flats or mother-in-law suites), attached in-law suites, detached secondary dwellings, kitchen expansions, garage conversions to ADUs or living space, screen-in lanai conversions to conditioned space, and full ground-floor footprint expansions. In St. Pete, master suite additions and ground-level expansions on slab homes are the most common — usually because the original 1950s–1970s footprint is too small for the lot's value.
Sometimes — it depends on your zoning and lot size. St. Petersburg updated its accessory dwelling unit (ADU) rules in recent years and many residential lots now allow accessory dwellings — both attached in-law suites built off the main house and detached secondary dwellings (also called granny flats or detached mother-in-law suites). Setbacks, parking, lot coverage, and impervious surface ratios all matter, and a garage conversion to an ADU has different rules than a new detached unit. We check the zoning and the deed restrictions before you commit to a design.
Five phases: free pre-construction walkthrough, design and structural engineering (4–8 weeks), permitting (8–16 weeks lately in Pinellas), construction (4–7 months for typical additions), and final inspections. We're with you the whole way — pulling permits, scheduling inspectors, running weekly budget reports. You don't chase any of it.
It can. If the cost of the addition plus any other improvements you make in the same year exceeds 50% of the structure's pre-improvement market value, FEMA requires the whole structure brought to current flood code — which usually means elevation. On most St. Pete addition projects we run that calculation before design even starts, because if you're close to the line it changes the whole approach.
Most master suite additions in St. Pete run $150K–$280K for 350–500 sq ft, including a primary bath. Cost depends on foundation type (slab tie-in is harder), roof structure, whether the existing HVAC can handle the load, and finish level. Waterfront and flood-zone lots add elevation considerations that can push 20–40% higher.
On a clean, fully-engineered plan set, St. Petersburg Building Department addition permits typically issue in 3–6 weeks. Add 2–4 weeks if structural revisions come back, and add 6–12 weeks if the property is inside a historic district and requires a Certificate of Appropriateness (COA) from the Community Planning & Preservation Commission before the building permit can even start review. We pull permits ourselves on every project — building, electrical, plumbing, mechanical, roofing, windows — with FL Product Approval (NOA) numbers already attached to every impact window, door, and roofing assembly so plan review doesn't stall.
Nothing means more to us than making our clients happy, unless perhaps it is making them so happy they come back to us or refer us to their friends and family!
"We had multiple contractors tell us that our 100-year old bungalow in Old Southeast should be torn down instead of remodeled. Revolution worked with us on an extensive plan to rebuild structural components and remodel the entire house. Now we have the best house in the block!"
"The guys at Revolution have done projects for us in two houses now. They added a master bathroom for us in northeast St Pete and then remodeled every square inch of a 4500-sq. ft house in Pinellas Pt. Through every challenge over two years of construction they have been there pushing our projects forward. We wouldn't use anybody else!"
"Awesome company! I had Revolution Contractors do some work on my house and did an amazing job!!! The guys there are great to work with and very professional and knowledgeable on there work. I am very happy they way there work came out and will be getting more work done on my house from them."
"Find them to be very professional, provide sufficient info for bidding, easy to contact, and most importantly they pay good. All and all NuTrend really enjoys a very productive and lucrative relationship with Revolution Contractors would recommend them and do often"
"On a challenging structural project for an investment property Revolution saw me through all sorts of headaches with the building department and were able to carry off multiple layout changes with gorgeous results. They've done multiple projects for my family as well as my group of closest friends and are now working on my primary residence!"
"Revolution Contractors have helped my family on numerous projects, providing guidance and honesty throughout all projects. The crew is hardworking and reliable. The owners are quick to respond and very honest. Definitely would recommend!"
SMALL JOBS. BIG STANDARDS.
Licensed carpenters for the repairs and small projects that are too important to trust to an unlicensed handyman. Same crew, same standards, smaller scope.
Home AdditionReal cost ranges by addition type — first-floor, second-story, garage conversions, and ADUs with St. Pete project data.
Read Guide →
Home AdditionPhase-by-phase timeline from architect selection through final inspection — 12-18 months of what actually happens.
Read Guide →
Home AdditionsCosts, permits, and zoning reality for detached, attached, garage-conversion, and second-story ADUs in St. Pete.
Read Guide →
Home AdditionsFlorida room additions in St. Pete cost $20K-$120K+ depending on size and finish level. Cost tables, permit process, and the impact glass exemption most contractors skip.
Read Guide →
Custom HomeThe decision framework for homeowners weighing all three options, including the FEMA 50% Rule that sometimes makes the decision for you.
Read Guide →
CoastalThe FL Building Code 9th Edition takes effect Dec 31, 2026 — ASCE 7-22, expanded 160 mph wind zones, NOA changes. What it means for your 2026-2027 project.
Read Guide →
