Apply for Building Permit
Your building permit is legal authorization to construct your addition. Without it, you risk stop-work orders, fines, forced demolition, and problems selling your home. This is the most critical permit in your project.
Quick Summary
Typical cost
$1,500-$5,000+
Review time
2-8 weeks
Who applies
Contractor or homeowner
Why This Step Matters
The building permit process ensures your addition meets safety codes and zoning requirements. While it can feel like bureaucratic red tape, permits protect you by requiring professional review of structural, electrical, and other safety-critical elements before and during construction.
Never Start Without a Permit
Building without a permit can result in fines of $500-$5,000+ per day, stop-work orders, and being forced to tear down completed work. When you sell, unpermitted work must be disclosed and can kill deals or reduce your home's value by 10-20%.
Required Documents for Permit Application
Architectural Plans
Complete construction drawings including floor plans, elevations, sections, and site plan. Must be stamped by a licensed architect or engineer in most jurisdictions. Plans should show dimensions, materials, and relationship to existing structure.
Structural Engineering
Engineer-stamped structural drawings and calculations showing foundation design, framing details, beam sizes, and how the addition connects to existing structure. Required for any structural work.
Site Plan / Survey
An updated property survey showing the proposed addition, setback distances, lot coverage calculations, and relationship to property lines. May need to be prepared by a licensed surveyor.
Mechanical/Electrical/Plumbing Plans
Drawings showing HVAC ductwork, electrical panel upgrades, new circuits, plumbing runs, and fixtures. May require separate engineering stamps depending on scope and local requirements.
Energy Compliance
Title 24 report (California) or equivalent energy compliance documentation showing insulation values, window efficiency, HVAC sizing, and lighting. Required in most states for additions over a certain size.
The Permit Application Process
Submit Application Package
Submit your complete plans and application form to the building department. Many jurisdictions now accept electronic submissions. Pay the initial plan review fee (typically $500-$2,000).
Pro tip: Call the building department before submitting to confirm their current checklist. Requirements change, and incomplete applications cause delays.
Plan Review Period
Multiple departments review your plans: building, planning/zoning, fire, public works. Each checks compliance with their codes. This typically takes 2-8 weeks depending on jurisdiction and workload.
- • Building: Structural, energy, accessibility codes
- • Planning: Zoning, setbacks, lot coverage
- • Fire: Smoke detectors, egress, sprinklers
- • Public Works: Drainage, sewer, utilities
Address Corrections
Most first submissions receive correction letters. This is normal—plan checkers often request clarifications or identify code issues. Your architect or engineer addresses these and resubmits revised plans.
Expect 1-2 rounds of corrections. Budget 2-4 extra weeks for the back-and-forth. Rushing resubmittals often creates more problems.
Pay Permit Fees and Pick Up
Once approved, you'll pay the remaining permit fees (based on project valuation) and receive your stamped plans and permit card. The permit must be posted visibly at the job site throughout construction.
Keep copies of everything. Your stamped plans are your "build to this" document. Any deviations require permit revisions.
Understanding Permit Costs
Permit fees are typically calculated as a percentage of project valuation, plus various flat fees. Here's what to expect:
| Fee Type | Typical Cost | Notes |
|---|---|---|
| Plan Review Fee | $500-$2,000 | Due at submission |
| Building Permit Fee | 1-3% of valuation | Due at permit issuance |
| School Impact Fee | $2-$5/sq ft | Varies by jurisdiction |
| Utility Connection Fees | $200-$1,000+ | If upgrading service |
| Other Impact Fees | $500-$3,000+ | Parks, traffic, etc. |
For a typical $150,000 addition, expect total permit costs of $2,500-$6,000.
Realistic Timeline Expectations
Fast Markets (2-4 weeks)
- • Smaller jurisdictions
- • Simple additions under 500 sq ft
- • Complete, professional submissions
- • No variances needed
Slow Markets (6-12 weeks)
- • Major metro areas
- • Large or complex additions
- • Historic district review
- • Environmental concerns
Build in buffer time. If the building department says 4 weeks, plan for 6-8. Delays are common and shouldn't derail your contractor schedule.
Frequently Asked Questions
Should my contractor or I apply for the permit?
Typically, the licensed contractor applies as the "permit holder"—they're responsible for code-compliant construction and passing inspections. Some homeowners pull their own permits for owner-builder projects, but this transfers liability to you. Discuss this with your contractor.
Can I start site prep before the permit is issued?
Only with explicit building department approval. Some jurisdictions allow a separate "grading permit" or "demolition permit" to run concurrently with building permit review. Never start foundation or structural work without a building permit in hand.
What happens if plans change during construction?
You'll need a permit revision. Submit the proposed changes to the building department for review. Minor changes may be approved by the inspector; major changes require formal plan review. Never make structural changes without revising the permit—inspectors will catch it and may require demolition.
How long is the permit valid?
Most permits are valid for 6-12 months and can be extended if work is progressing. If no work occurs for an extended period (typically 180 days), the permit may expire and you'll need to reapply. Keep your project moving to avoid permit expiration issues.
Ready for the Next Step?
In addition to your main building permit, you'll need separate permits for structural, electrical, plumbing, and mechanical work. These are often pulled by specialty subcontractors.