ADU Permit Guide for St. Petersburg, Florida — Step-by-Step Process (2026)

Before submitting any paperwork, you must establish that your property qualifies for an ADU. Start with property ownership verification through a current deed or title report dated within 30 days. The city requires proof of clear title without liens that could complicate construction.

Your property must contain an existing legal dwelling as the primary residence. This means a house with a valid Certificate of Occupancy, not a vacant lot or illegally converted structure. Pull your property records from the Pinellas County Property Appraiser's office to confirm your dwelling's legal status.

Zone verification is critical. St. Petersburg allows ADUs only in specific residential zones: NS-1 (Neighborhood Serving), NS-2 (Neighborhood Serving), and NT-1 (Neighborhood Traditional). Use the city's online zoning map /search to verify your property's designation. Print this verification – you'll need it for your application.

Several factors will disqualify your property immediately. Properties within the historic districts require additional Historic Preservation Commission review, adding 3-6 months to your timeline. HOA restrictions often prohibit ADUs entirely, regardless of city approval. Properties with existing code violations must resolve these issues before ADU permit submission.

Flood zone compliance adds complexity and cost. Properties in AE, VE, or AH flood zones require elevated construction and engineered foundation systems. Check your FEMA flood map designation using the city's flood zone lookup tool /search. Flood zone requirements can increase construction costs by $25,000-$50,000.

Properties smaller than 5,000 square feet face significant setback challenges. With minimum 10-foot rear setbacks and 5-foot side setbacks, smaller lots may lack sufficient buildable area for a code-compliant ADU.

Utility capacity verification prevents costly surprises. Contact the city's Utilities Department at (727) 893-7261 to confirm your water and sewer capacity can support additional dwelling units. Properties with aging or undersized service lines may require expensive utility upgrades before construction begins.

Your pre-application research determines project viability and prevents expensive mistakes. Start with setback verification using the city's setback calculator /tools/setback-calculator. ADUs require minimum 10-foot rear setbacks, 5-foot side setbacks, and 20-foot front setbacks from property lines.

For NS-1 and NS-2 zones, maximum ADU size is 1,200 square feet or 50% of the primary dwelling's floor area, whichever is smaller. NT-1 zones allow up to 1,000 square feet. These calculations include all interior heated space but exclude porches, patios, and unheated storage areas.

St. Petersburg requires one additional parking space for each ADU bedroom. This parking must be on-property – street parking doesn't count. Measure your driveway and calculate whether you can accommodate the additional parking without violating setback requirements.

Tree preservation requirements affect many properties. The city protects trees with diameters exceeding 12 inches at chest height. Tree removal requires separate permits and mitigation fees ranging from $500-$2,000 per tree. Schedule a free tree assessment by calling the Parks and Recreation Department at (727) 893-7335.

Pre-application meetings with the Planning Department cost $250 and typically occur within 2-3 weeks of scheduling. These 30-minute sessions identify potential issues before formal submission. Bring your site survey, preliminary design sketches, and zoning verification printout.

During pre-application meetings, planners review your setback calculations, discuss design requirements, and identify any neighborhood-specific restrictions. They'll flag potential issues like stormwater management requirements or fire department access concerns.

Hurricane wind load requirements add structural complexity. St. Petersburg sits in Wind Zone 3, requiring structures to withstand 140+ mph winds. This means engineered foundation systems, hurricane straps, and impact-resistant windows. Discuss these requirements during your pre-application meeting to understand cost implications.

The pre-application meeting summary becomes your roadmap. Planners provide written comments identifying specific code sections, required studies, and design modifications. This document prevents misunderstandings during formal review.

Professional architectural plans are mandatory – St. Petersburg doesn't accept hand-drawn sketches or basic floor plans. Your plan set must include site plans, foundation plans, floor plans, four elevation drawings, roof plans, and electrical/plumbing schematics.

Site plans require specific detail levels. Show all existing structures, proposed ADU location, property lines with dimensions, setback measurements, existing and proposed driveways, utility locations, and drainage patterns. Include a north arrow and scale notation (typically 1/16" = 1').

Structural engineering calculations are required for all ADUs due to hurricane wind loads and potential flood zone requirements. Your structural engineer must be licensed in Florida and familiar with the Florida Building Code{:target="_blank"}. These calculations typically cost $2,500-$4,500 and take 2-3 weeks to complete.

Energy compliance follows the Florida Energy Efficiency Code (based on IECC 2020). Your plans must show insulation R-values, window U-factors, and HVAC efficiency ratings. Include a completed energy compliance form with your submission. Many architects overlook this requirement, causing automatic rejections.

Foundation details require extra attention in flood-prone areas. Show foundation type (slab, crawl space, or elevated), flood vent locations if required, and tie-down specifications for hurricane resistance. Elevated foundations in flood zones must include breakaway wall details and utility protection measures.

Electrical plans must show panel locations, circuit layouts, outlet placement, and lighting plans. Include load calculations proving your existing electrical service can handle the additional dwelling. If service upgrades are needed, coordinate with Tampa Electric Company (TECO) for timeline and cost estimates.

Plumbing plans show fixture locations, waste line routing, and water line connections. Include calculations proving adequate water pressure for both dwellings. St. Petersburg requires separate utility meters for ADUs, so show proposed meter locations and utility easement access.

Plan review fees depend on project valuation. For a typical 800-square-foot ADU valued at $150,000, expect plan review fees of approximately $1,200-$1,800. These fees are separate from permit fees and due at submission.

Working with experienced local architects saves time and money. They understand St. Petersburg's specific requirements and have established relationships with plan reviewers. Expect architectural fees of $8,000-$15,000 for complete plan sets.

St. Petersburg requires online submission through the ProjectDox portal accessed via the city's Development Services website. Paper submissions are no longer accepted except for specific hardship cases approved in advance.

Create your ProjectDox account 2-3 days before submission to resolve any login issues. The system requires Adobe Acrobat Pro to combine multiple plan sheets into single PDF files. Each discipline (architectural, structural, electrical, plumbing) requires separate file uploads.

Required documents include completed building permit application (Form BLD-001), signed and sealed architectural plans, structural engineering calculations, energy compliance worksheets, site survey completed within 180 days, property deed or title commitment, and zoning verification letter.

• Application fees vary based on construction valuation. For a typical 800-square-foot ADU:
• Base building permit fee: $1,200-$1,800
• Plan review fee: $800-$1,200
• Impact fees: $2,500-$4,000
• Fire review fee: $150
• Public works review fee: $200
• Environmental review fee: $100

Pay all fees online during submission. The system accepts credit cards but charges 2.9% processing fees. Checks are not accepted for online submissions.

Construction valuation determines fee calculations. St. Petersburg uses $175-$300 per square foot depending on finish level. A 800-square-foot ADU with standard finishes typically values at $140,000-$160,000 for fee calculation purposes.

Impact fees fund infrastructure improvements and vary by location within the city. Properties served by newer utilities typically pay lower impact fees. Contact the Development Services Department at (727) 893-7247 for specific impact fee calculations before submission.

Common submission errors include unsigned plan sheets, missing structural calculations, incomplete energy forms, and incorrect fee calculations. Double-check all requirements using the city's submission checklist /tools/codes/st-petersburg before uploading files.

The system generates a permit number and receipt immediately upon successful submission. Print these documents – you'll reference the permit number throughout the process. Expect automated email confirmation within 24 hours.

Plan review begins within 5 business days of submission but completion takes 6-12 weeks depending on plan complexity and reviewer workload. The city provides online tracking through ProjectDox showing current review status.

Multiple departments review ADU plans simultaneously. Building Department reviews structural and code compliance. Fire Department reviews access and safety systems. Public Works reviews stormwater and utility impacts. Planning Department reviews zoning compliance and design standards.

First-round plan check comments arrive via email with detailed correction lists. These comments reference specific code sections and required modifications. Most projects receive 15-25 comments requiring plan revisions.

Common plan check comments include missing structural details, inadequate stormwater management, incorrect setback calculations, missing fire access routes, and incomplete energy compliance documentation. Address each comment specifically – generic responses cause rejections.

Plan revisions require your architect and engineer to modify drawings and resubmit through ProjectDox. Revision submissions cost additional fees: $400-$600 for minor revisions, $800-$1,200 for major changes requiring complete re-review.

Second-round reviews take 3-4 weeks and typically generate 5-10 additional comments. Most projects achieve approval after 2-3 review cycles. Complex projects with flood zone or historic district requirements may require 4-5 cycles.

Expedited review costs an additional 50% fee but guarantees 3-week turnaround for each review cycle. This option makes sense for time-sensitive projects but doesn't guarantee fewer correction cycles.

Direct communication with plan reviewers occurs only through official channels. Call the Development Services main line at (727) 893-7247 to schedule reviewer meetings if written comments need clarification.

Review extensions may be necessary if your team needs extra time for complex corrections. Request extensions before the 180-day review period expires to avoid permit expiration and resubmission requirements.

Final approval triggers permit issuance and fee collection for remaining balances. Permits are valid for one year with possible six-month extensions. Construction must begin within this timeframe to maintain permit validity.

Permit issuance authorizes construction start but requires immediate inspection scheduling. Contact the city's Inspection Department at (727) 893-7285 to establish your inspection sequence and inspector contact information.

• Required inspections follow specific construction phases:
• Footing/foundation inspection (before concrete pour)
• Slab inspection (before concrete pour, if applicable)
• Framing inspection (after framing completion, before insulation)
• Electrical rough inspection (after wire installation, before drywall)
• Plumbing rough inspection (after pipe installation, before drywall)
• Mechanical rough inspection (after ductwork installation, before drywall)
• Insulation inspection (before drywall installation)
• Drywall inspection (after drywall completion, before painting)
• Final electrical inspection (after fixture installation)
• Final plumbing inspection (after fixture installation)
• Final mechanical inspection (after system completion)
• Final building inspection (before Certificate of Occupancy)

Schedule inspections online through the city portal or by calling the automated line at (727) 893-INSP (4677). Inspections require 24-hour advance notice and occur between 8:00 AM and 3:00 PM, Monday through Friday.

Foundation inspections verify proper depth, reinforcement placement, and anchor bolt installation. Hurricane tie-down requirements receive special attention. Have your structural drawings on-site for inspector reference.

Framing inspections check structural member sizes, spacing, and connections. Inspectors verify hurricane strap installation and proper bearing wall construction. Failed framing inspections typically involve missing or incorrect structural connections.

Rough inspections for electrical, plumbing, and mechanical systems verify code compliance before drywall conceals the work. Have code books and permit plans available during these inspections.

Failed inspections require corrections before proceeding. Re-inspections cost $100 each and require 24-hour rescheduling. Address all noted violations completely – partial corrections result in additional failures.

Insulation inspections verify proper R-values and installation techniques. Compressed or missing insulation causes failures and energy compliance violations.

Final inspections check completed work, safety systems, and overall code compliance. Inspectors verify proper egress, smoke detector installation, and finish work quality.

Keep detailed inspection records and correction documentation. These records may be needed for warranty work or future property sales.

Final building inspection approval triggers the Certificate of Occupancy (CO) application process. Schedule your final inspection only after completing all finish work, installing all fixtures, and resolving any outstanding violations.

The CO application requires proof of utility connections, final electrical inspection approval, final plumbing inspection approval, and final mechanical inspection approval. Submit these documents through ProjectDox within 30 days of final inspection approval.

Address assignment occurs during the CO process. The city assigns a separate address for your ADU, enabling legal rental and separate utility accounts. This process takes 5-10 business days and costs $75.

Utility connections require separate meters for ADUs. Coordinate with TECO for electrical service and the city's Utilities Department for water/sewer connections. Schedule these installations 2-3 weeks in advance to avoid delays.

Final utility inspections verify proper meter installation and service capacity. Both electrical and water services require separate inspections after connection completion.

The Certificate of Occupancy authorizes legal occupancy and rental of your ADU. Without this document, occupancy violates city codes and creates liability issues.

CO issuance typically occurs 3-5 business days after completing all requirements and receiving final utility approvals. The city emails the CO certificate, which serves as legal proof of compliance.

Property tax assessments increase following CO issuance. Pinellas County Property Appraiser will reassess your property value including the new ADU. Expect property tax increases of $1,500-$3,500 annually.

Recording the ADU with Pinellas County creates permanent property records. While not required, this documentation helps with future sales and refinancing.

Insurance updates are necessary before occupancy. Contact your insurance agent to modify coverage for the additional dwelling unit. Rental properties require landlord insurance policies.

HOA notifications may be required even if the ADU complies with city codes. Check your HOA governing documents and notify the association of your new structure.

Setback violations cause 35% of ADU permit denials. Property owners frequently miscalculate distances from property lines or fail to account for easements. Survey all property lines professionally and verify setback measurements using the city's setback calculator /tools/setback-calculator. Remember that setbacks measure from the closest building element, including roof overhangs and foundations.

Incomplete or incorrect plans trigger automatic rejections. Missing structural calculations, unsigned plan sheets, or inadequate detail drawings stop review processes immediately. Use experienced local architects familiar with St. Petersburg requirements. Verify all plan sheets are signed and sealed by Florida-licensed professionals before submission.

Utility capacity issues delay 25% of ADU projects. Older neighborhoods often lack adequate water pressure or sewer capacity for additional dwelling units. Contact the Utilities Department at (727) 893-7261 for capacity verification before design completion. Utility upgrades can cost $15,000-$35,000 and require separate permits with 8-12 week timelines.

HOA restrictions override city zoning in many neighborhoods. Even properties zoned for ADUs may face HOA prohibitions through deed restrictions or architectural guidelines. Review your HOA governing documents completely and obtain written approval before spending money on plans. Some HOAs prohibit separate entrances or require design conformity with existing homes.

Historic district requirements add 3-6 months to standard timelines. Properties within designated historic districts require Historic Preservation Commission review for design compatibility. This process includes public hearings and detailed design requirements. Contact the Planning Department's historic preservation staff early in your planning process to understand specific requirements.

Fire department access problems affect corner lots and properties with limited street frontage. Fire codes require access within 150 feet of all building areas via approved routes. Narrow driveways, landscaping obstacles, or inadequate turning radii cause rejections. Schedule pre-application meetings with Fire Department plan reviewers to identify access solutions.

Tree preservation violations result in stop-work orders and significant fines. St. Petersburg protects mature trees through strict preservation ordinances. Tree removal without permits incurs fines up to $5,000 per tree plus mitigation costs. Schedule tree assessments before finalizing ADU locations and obtain proper removal permits for unavoidable impacts.

Flood zone non-compliance creates expensive reconstruction requirements. Properties in flood zones must meet elevation requirements and include proper flood vents. Incorrect foundation design or inadequate flood protection requires complete reconstruction. Hire structural engineers experienced with FEMA requirements and obtain flood zone compliance verification before construction begins.

Energy code violations delay final approvals even after construction completion. Missing insulation documentation, incorrect window specifications, or inadequate HVAC efficiency ratings prevent Certificate of Occupancy issuance. Maintain detailed energy compliance records throughout construction and schedule required inspections at proper intervals.

Stormwater management issues affect properties that increase impervious surfaces beyond thresholds. ADUs may trigger requirements for retention ponds, rain gardens, or underground storage systems. These requirements add $5,000-$15,000 to project costs and require separate engineering design. Discuss stormwater impacts during pre-application meetings to identify requirements early.