Research by DoINeedAPermit Research Team · Updated May 2026
The Short Answer
Yes. Biloxi enforces Mississippi Building Code for wind retrofits, including roof-to-wall straps, hurricane shutters, impact windows, and garage-door bracing. The City of Biloxi Building Department must issue a permit and conduct inspections before you're eligible for insurance discounts.
Biloxi sits in the coastal high-wind zone and adopts the Mississippi Building Code (which mirrors the International Building Code with state amendments). Unlike some inland Mississippi cities that treat hurricane retrofits as routine alterations with over-the-counter permits, Biloxi enforces mandatory plan review for wind-mitigation work — especially roof-to-wall connections and secondary water barriers — because the city is subject to Design Category D (160 mph design wind speed) per the National Hurricane Center's wind-speed maps. The Biloxi Building Department requires a licensed engineer's stamp on roof-strap details and garage-door bracing, and the final inspection report must be signed by a licensed wind-mitigation inspector to unlock insurance premium reductions. This is distinct from inland Harrison County jurisdictions (e.g., Long Beach, D'Iberville) which sometimes permit-exempt shutters under 50 sq ft; Biloxi does not grant that exemption. You'll also encounter stricter secondary water barrier (peel-and-stick underlayment) documentation than non-coastal cities, since Biloxi's flood-zone proximity means insurance carriers and the city both demand proof of water-intrusion prevention.

What happens if you skip the permit (and you needed one)

Biloxi hurricane retrofit permits — the key details

Biloxi requires permits for roof-to-wall connection upgrades, secondary water barriers, hurricane shutters, impact-rated windows, and garage-door bracing. The core rule is Mississippi Building Code Chapter 3 (Wind Loads), which adopts the International Building Code and sets Design Category D (160 mph basic wind speed) for coastal Biloxi. Any work that increases wind resistance or ties roof decking to the wall framing — straps, clips, bolts, or fasteners — must be designed by a licensed engineer and permitted. Similarly, exterior openings (windows, doors, garage doors) that are upgraded to impact-rated materials require plan review to verify the frames are anchored per code. The Biloxi Building Department does not issue permits over the counter for wind-mitigation work; all submissions go through plan review, which typically takes 5-10 business days. You cannot rely on exemptions for 'minor repairs' — even a single hurricane-shutter panel installation triggers the permit requirement in Biloxi, unlike some inland cities.

Secondary water barriers are a critical local requirement in Biloxi, driven by the city's flood risk and insurance-carrier mandates. Mississippi Building Code Section R908.2 (Underlayment) requires a peel-and-stick or synthetic underlayment under roof shingles, especially in high-wind zones. Biloxi inspectors will request photographic documentation of underlayment installation at the starter course and at every valley, and the final inspection includes a walkthrough of the roof to verify coverage. This is not an afterthought — it's a line item on the permit checklist and a required submittal. Many contractors underestimate the cost and timeline of this work; budget $0.75–$1.50 per sq ft of roof deck for materials and labor, and allow an extra 1-2 weeks for the inspector to schedule a mid-phase (rough) inspection before shingles go down.

Roof-to-wall straps and fastener specifications are the second major sticking point in Biloxi. Mississippi Building Code Table R602.3(1) specifies the rafter-to-top-plate connection requirement based on wind speed. For Design Category D (160 mph), you need metal straps or hurricane ties rated for at least a 700-pound pullout force, spaced at every rafter or truss (typically 16 or 24 inches on center). Biloxi inspectors will not accept a generic strap schedule; the engineer's plan must call out exact strap size, fastener size (nails or bolts), spacing, and reference the product's third-party test certificate. If you miss even one truss connection or use a lower-rated fastener, the inspection will fail. The cost of engineer's design and materials runs $1,500–$3,500 for a typical 1,500-2,000 sq ft roof; the Biloxi Building Department will ask to see the engineer's calculations and the product test report before they'll issue the permit.

Garage-door bracing is mandatory for single-layer (uninsulated) doors in Biloxi, and increasingly required for insulated doors as well. The garage door is the largest opening on most homes and can depressurize the entire structure if breached by wind. Mississippi Building Code Section R609.3.2 requires either impact-rated doors or bracing. Bracing typically uses horizontal cross-bracing kits (Armor-Dade, Mighty-Brace, or similar), which must be engineered for the design wind speed and installed by a licensed contractor. The engineer's stamped design must show the exact bracing configuration, bolt sizes, and anchor points. Expect $800–$2,000 for a single-door kit plus installation, and plan for a 2-3 hour installation. The Biloxi inspector will conduct a walkthrough inspection post-installation to verify bolt torque and anchor attachment.

The final step is the wind-mitigation insurance-discount inspection, which is separate from the city permit inspection. Once the Biloxi Building Department issues the final permit sign-off, you must hire a licensed wind-mitigation inspector (different from the city inspector) to document the retrofit work and complete Florida form OIR-B1-1802 (Homeowners Property Insurance Hurricane Loss Mitigation Verification Form). This form is the key to unlocking insurance premium discounts — typically $300–$800 per year. The wind-mitigation inspector will photograph each retrofit element, measure rafter spacing, document fastener types, and certify the work. Biloxi does not issue the permit until the city inspection passes, but the insurance discount does not apply until the OIR-B1-1802 is signed, filed with your insurer, and your policy is updated. Plan 2-3 weeks for this final step after the city gives final approval.

Three Biloxi wind / hurricane retrofit scenarios

Scenario A
Roof-to-wall strap retrofit on a 1,500 sq ft 1970s ranch in East Biloxi (elevated on pilings, no secondary water barrier yet)
Your 1970s ranch is on pilings in the East Biloxi flood zone; the original roof framing has no hurricane ties — just toe-nailed rafters. You want to add metal straps (700-pound rated) at every 16-inch rafter, plus peel-and-stick underlayment under new shingles. Step one: hire a licensed engineer in Mississippi to design the strap layout and specify fastener sizes. The engineer will reference Mississippi Building Code Table R602.3(1) for a 160 mph design wind speed and call out Simpson H2.5 (or equivalent) hurricane ties with 8d nails or bolts. Total design cost: $400–$600. Step two: submit the engineer's plan, site photos, and existing roof survey to the Biloxi Building Department. Expect a 7-10 day review and one round of clarification questions (e.g., 'Confirm rafter-to-top-plate nail size'). Step three: pull the permit ($250–$400 based on $18,000 estimated retrofit cost). Step four: contractor installs underlayment, then straps, then shingles. Expect three inspections: (1) underlayment rough-in before shingles, (2) strap installation before shingles cover them, (3) final roofing. Timeline: 4-6 weeks. Total cost: engineer $400-600, permit $250-400, materials and labor $8,000–$12,000, wind-mit inspection $150-250. Insurance savings: $400–$600 annually.
Permit required | Licensed engineer stamp required | Design wind speed 160 mph | Peel-and-stick underlayment mandatory | H2.5 strap or equivalent | Three inspections (rough, installation, final) | Permit fee $250–$400 | Total retrofit $9,000–$13,000 | Insurance discount $400–$600/year
Scenario B
Impact-rated windows (8 windows, 120 sq ft) and aluminum hurricane shutters on a Gulf-view condo in Biloxi Beach District (secondary water barrier already compliant)
Your Gulf-front condo (built 2005, already has code-compliant secondary water barrier) needs new impact-rated windows and accordion shutters on all ocean-facing elevation. This is a different permit track than Scenario A because it's openings + exterior cladding, not structural framing. Step one: buy shutter hardware and window units that carry third-party certifications (ASTM E1996 large missile impact test or Miami-Dade TAS 201 label); do not substitute unrated shutters. Step two: submit the window spec sheet and shutter installation plan to Biloxi Building Department. The plan must show: anchor-point spacing (typically 12-16 inches), fastener size (5/16-inch stainless bolts, minimum), and shutter profile (height, width, material). Step three: pull the permit ($200–$350, since opening upgrades are lower-cost than roof work). Step four: contractor installs windows first (hire a licensed window installer), then shutter tracks and hardware. Expect two inspections: (1) window frame anchoring before interior trim, (2) shutter installation and bolt-torque check. Timeline: 3-4 weeks. The surprise here is that Biloxi requires the shutter installer to be licensed and bonded if the job exceeds $5,000; check with the city in advance. Total cost: windows $6,000–$10,000, shutters $3,000–$5,000, permit $200-350, wind-mit inspection $150-250. Insurance savings: $200–$400 annually (less than roof straps, since openings are secondary).
Permit required | Third-party impact test certificate (ASTM E1996 or TAS 201) required | Licensed window installer recommended | Shutter fasteners 5/16-inch stainless (12-16 inch spacing) | Two inspections (frame anchor, shutter final) | Permit fee $200–$350 | Total retrofit $9,500–$15,500 | Insurance discount $200–$400/year
Scenario C
Garage-door bracing retrofit (single-layer uninsulated door) + secondary water barrier (peel-and-stick) on 2000 sq ft split-level in South Biloxi
Your 2000 sq ft split-level has a single-layer, uninsulated garage door and old asphalt shingles with no underlayment. You want to brace the garage door and upgrade roofing with secondary water barrier. These are two separate permit lines but often filed together. Step one: for the garage-door bracing, buy a cross-bracing kit (Armor-Dade HD or similar) rated for Design Category D winds. You'll need an engineer stamp on the installation plan showing bolt holes, anchor points, and a callout that the door frame can handle the brace loading. This is crucial — some garage-door frames (older aluminum) cannot safely accept the loads from bracing and may require frame reinforcement, adding $1,000–$1,500. Have the engineer assess the door frame in advance. Step two: for the roofing, submit an engineer's design showing strap layout (if rafters are old) and secondary water barrier specification. Some inspectors in Biloxi will accept a standard specification ('GAF 25-lb felt underlayment, ASTM D1970') without an engineer; check with the department's plan-review team before submitting to save time. Step three: pull one permit that covers both items (single address, two scopes). Expect a 5-7 day review. Permit fee: $300–$500 (combined). Step four: contractor starts with roof underlayment rough-in, then roof work, then garage-door bracing. Three inspections: (1) roof underlayment, (2) garage-door bracing bolt tightness, (3) final roofing and bracing. Timeline: 5-7 weeks (because roof work can't proceed until underlayment is in). Total cost: engineer $500–$700, permit $300-500, door bracing $1,500–$2,500, roofing materials and labor $6,000–$10,000, wind-mit inspection $150-250. Insurance savings: $350–$650 annually (bracing alone saves $150–$250; roof underlayment saves an additional $200–$400).
Permit required (combined garage + roof) | Licensed engineer required (garage-door frame assessment + roof strap design) | Design wind speed 160 mph | Garage-door frame reinforcement may be required ($1,000–$1,500 extra) | Peel-and-stick underlayment required | Cross-brace kit (Armor-Dade or equiv.) | Four inspections (underlayment rough, brace install, roof final, overall final) | Permit fee $300–$500 | Total retrofit $9,000–$14,500 | Insurance discount $350–$650/year

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Biloxi's Design Category D wind speed and why it matters to your permit timeline

Biloxi is located in Design Category D per the International Building Code wind-speed maps, meaning the basic wind speed is 160 mph (the highest category). This is not just a number — it drives every permit decision in the city. When you submit a hurricane-retrofit plan to the Biloxi Building Department, the plan-review engineer will check every connection, fastener, and detail against a 160 mph gust. This is different from an inland Harrison County city (e.g., Long Beach, which is Design Category C at 140 mph), where certain smaller retrofits might qualify for fast-track permitting. Biloxi has no fast-track window; all wind-mitigation work goes through full plan review, which typically adds 7-10 days to the timeline compared to towns where the design wind speed is lower.

The 160 mph standard means that when your engineer designs roof straps, garage-door bracing, or shutter anchors, they must show compliance with the higher load. This often means upgrading fastener sizes or spacing compared to what the same retrofit would require in a non-coastal city. For example, a garage-door brace kit that is rated for 140 mph winds might not be acceptable in Biloxi; you'd need the 160 mph version, which is often a different model with thicker steel or more bolts. Contractors who work in both Biloxi and inland Mississippi often stock two versions of the same product, which adds complexity and cost.

The Biloxi Building Department's plan-review checklist is explicit about 160 mph compliance. If your engineer's plan doesn't include a line item stating '160 mph design wind speed per Mississippi Building Code and IBC Table R301.2(1),' the plan will be returned incomplete. This is not bureaucratic nitpicking — it ensures that your retrofit will actually survive the design storm. In practice, this means your engineer's design fees are slightly higher in Biloxi than they would be for the same retrofit in Long Beach or D'Iberville, often by 10-15% because of the added wind-load calculations.

Secondary water barriers in Biloxi: why the city and your insurer both demand proof

Biloxi's secondary water-barrier requirement stems from two sources: the Mississippi Building Code (which mirrors the IBC) and the insurance industry's underwriting standards. The code requires peel-and-stick underlayment (e.g., GAF FeltBrite, Owens Corning Duration, or equivalent) under roof shingles in all homes, but Biloxi's coastal proximity makes it a line-item inspection point. The reason: Biloxi sits at or near sea level with frequent heavy rain events, and roofs that lack underlayment are far more prone to secondary (water-intrusion) damage during and after hurricanes. Even if your roof frame survives 160 mph winds, if the shingles blow off and there's no peel-and-stick underneath, water pours into the attic and damages framing, insulation, and interior ceilings.

When you submit a permit for new roofing or roof-strap work, the Biloxi Building Department will ask for a 'secondary water barrier detail' in your plan. This is often just a cross-section drawing showing the underlayment layer under the shingle starter course, but it must be legible and labeled. You'll also be required to submit a photo during the rough-in inspection showing the underlayment is in place before shingles go down. Many homeowners skip this step, thinking it's a formality, but inspectors in Biloxi do not issue final approval until they see underlayment installed. If your contractor glosses over it, you'll get a failed inspection and a 2-week delay while the contractor adds underlayment after the fact (which is expensive and disruptive).

Your insurance carrier also cares deeply about secondary water barriers in Biloxi. When the wind-mitigation inspector fills out the OIR-B1-1802 form, one of the required checkboxes is 'secondary water barrier present.' If the box is unchecked, you lose a portion of your insurance discount, even if the city has already approved your roof. In some cases, carriers will refuse to renew a policy if a roof replacement does not include underlayment, especially in Biloxi. Plan on this as a required line item, not an optional upgrade: budget $0.75–$1.50 per sq ft for material and labor, and ensure your contractor understands that it's a permit checkpoint.

City of Biloxi Building Department
City of Biloxi, Biloxi, MS (contact City Hall main line for building department routing)
Phone: (228) 435-6237 (City of Biloxi main) — ask for Building Department | https://www.biloxi.ms.us (check for online permit portal or links under 'Building & Planning')
Monday–Friday, 8:00 AM–5:00 PM Central Time

Common questions

Do I need a permit for basic hurricane shutters in Biloxi?

Yes. Even a single accordion or roll-down shutter requires a permit in Biloxi, regardless of size. The permit process includes plan review of the shutter specification (fastener type, anchor spacing, product rating) and a final inspection to confirm installation. Do not assume that small shutter jobs are exempt — Biloxi enforces the permit requirement consistently. The permit usually costs $150–$250 for shutters alone, and you'll need a wind-mitigation inspector's sign-off to unlock insurance discounts.

Can I do a hurricane retrofit as an owner-builder in Biloxi, or do I need to hire a contractor?

Mississippi allows owner-builders on owner-occupied homes, and Biloxi honors this for certain retrofit work (e.g., installing pre-made shutter hardware). However, structural work (roof-strap installation, garage-door bracing, window framing anchors) almost always requires a licensed contractor, because the Biloxi Building Department will demand proof of liability insurance and the contractor's state license during plan review. If you attempt structural work without a license, the city can issue a stop-work order. Hire a contractor for anything involving fasteners to the framing; you can do non-structural assembly (e.g., tightening bolts on pre-hung shutters) yourself.

What design wind speed does Biloxi use, and does it affect the retrofit I need?

Biloxi uses Design Category D (160 mph basic wind speed) per the Mississippi Building Code and International Building Code wind-speed maps. This is the highest category and means your retrofit components must be rated and engineered for 160 mph winds. For example, garage-door bracing that is rated only for 140 mph is not acceptable in Biloxi; you must buy the 160 mph version. All fasteners, straps, and anchors are checked against this standard during plan review. This higher standard increases material and engineering costs compared to inland cities.

How long does the permit review process take in Biloxi for a hurricane retrofit?

Typical timeline is 7-10 business days for plan review, assuming the plan is complete on first submission. If the Biloxi Building Department identifies missing information (e.g., no third-party product test certificate, no engineer stamp on garage-door bracing), they will issue a list of clarifications and you'll lose another 5-7 days waiting for resubmission. Best practice: review the department's permit checklist before you submit, and have your engineer or contractor confirm all required documents are included. From permit issuance to final inspection sign-off typically takes 4-6 weeks total.

Do I have to hire a licensed engineer for my hurricane retrofit in Biloxi, or can I submit the work myself?

Structural work (roof straps, garage-door bracing, roof-frame connections) requires a licensed Mississippi engineer's stamp on the design plan. The Biloxi Building Department will not review a structural plan without an engineer's seal. Openings (windows, shutters) can sometimes be permitted with just the manufacturer's third-party test certificate (ASTM E1996 or TAS 201) and an installation diagram, though the department may ask for engineer confirmation. When in doubt, hire an engineer; their fees ($400–$700 for a typical retrofit design) are far less costly than a rejected permit and redesign.

What is the OIR-B1-1802 form, and why do I need it in Biloxi?

The OIR-B1-1802 (Homeowners Property Insurance Hurricane Loss Mitigation Verification Form) is a Florida-origin form that is widely accepted in Biloxi by insurance carriers to document hurricane-retrofit work and unlock premium discounts. Once your city permit is issued and the work is complete, you hire a licensed wind-mitigation inspector to photograph each retrofit element (roof straps, shutters, braced garage door, etc.) and sign the form. You then file the form with your homeowner's insurance carrier, and they apply a discount (typically $300–$800 per year) to your policy. Without this form signed by a licensed inspector, you get no insurance discount even if the work is city-permitted.

If the Biloxi Building Department issues a final permit sign-off, do I automatically get an insurance discount?

No. The city permit and the insurance discount are two separate processes. The city inspector verifies code compliance; the insurance discount is unlocked only when a licensed wind-mitigation inspector completes the OIR-B1-1802 form and your carrier processes it. You must hire the wind-mit inspector separately (cost $150–$250) after the city gives final approval. This is a common point of confusion — many homeowners finish the city permit and assume the discount is automatic, then lose 6-12 months of savings because they didn't file the insurance form.

What happens if I install a hurricane retrofit without a Biloxi permit?

The Biloxi Building Department can issue a stop-work order and fines ($500–$1,000 per violation). More serious: if you later file a homeowner's insurance claim for wind or water damage, the carrier can deny the claim if they discover that retrofit work was done unpermitted and not disclosed. A denied claim can cost $50,000+ on a roof or structural repair. Additionally, unpermitted work will be flagged during a home sale (disclosure requirement), potentially tanking the deal or forcing you to remediate at your own cost. Always pull the permit upfront.

Do I need to upgrade my entire roof to get the secondary water-barrier requirement in Biloxi, or can I add underlayment to my existing roof?

You can add underlayment without replacing the roof, but it must be done correctly. The proper method is to remove existing shingles, install peel-and-stick underlayment over the deck, and re-shingle. Simply stapling underlayment over existing shingles is not code-compliant and will not pass inspection. If you are already re-roofing for other reasons, the secondary water barrier is a required line item on the same permit. If your roof is in good condition and you only want the retrofit for wind-mitigation discounts, the cost of a full re-roof with underlayment may not pay back in insurance savings for 7-10 years; in that case, focus on roof straps, shutters, and garage-door bracing instead.

Are there any Biloxi-specific local amendments to the Mississippi Building Code that affect my hurricane retrofit?

The Biloxi Building Department adopts the current Mississippi Building Code without major local amendments specific to wind retrofit. However, Biloxi's flood-zone status (FEMA flood plain and coastal high-hazard area) means that some retrofit projects may trigger additional flood-mitigation requirements (e.g., elevated HVAC units, flood-vents in foundation walls) depending on the project scope. Check with the city's plan-review team before submitting to confirm whether your retrofit has any flood-related requirements. Also, Biloxi has a separate Stormwater Management ordinance that may apply if you are replacing large roof areas or hardscape; the building department can clarify this during permit intake.

Disclaimer: This guide is based on research conducted in May 2026 using publicly available sources. Always verify current wind / hurricane retrofit permit requirements with the City of Biloxi Building Department before starting your project.