Research by DoINeedAPermit Research Team · Updated May 2026
The Short Answer
Yes. Simpsonville enforces South Carolina Building Code (SCBC), which adopts the International Building Code with state amendments. Any structural wind-mitigation work — roof-to-wall straps, secondary water barriers, impact shutters, reinforced garage doors — requires a permit and inspection. The crucial difference: SC ties retrofits to insurance discounts through the OIR-B1-1802 form, which ONLY a licensed South Carolina wind-mitigation inspector can certify after final inspection.
Simpsonville, in Greenville County, sits in IECC Climate Zone 3A with design wind speeds of 90 mph (3-second gust per SCBC Figure R301.2(1)). Unlike Florida's mandatory HVHZ (High Velocity Hurricane Zone) overlay, South Carolina treats wind retrofits as voluntary improvements — but the permit requirement is just as real. The city's critical local angle: Simpsonville Building Department (the arm of the City of Simpsonville municipal government) processes permits through the standard SC flow — no online portal or fast-track option unique to Simpsonville, but the city does recognize owner-builder applications per SC Code § 40-11-360, meaning homeowners can pull permits themselves without a licensed contractor. The insurance-discount carrot is substantial: an OIR-B1-1802 inspection (completed by a licensed SC wind-mitigation inspector, not the city inspector) unlocks 5-20% insurance premium reductions, often paying back a $3,000–$8,000 retrofit in 3-5 years. This is where Simpsonville differs from generic 'permit required' — the real value is the inspection paperwork, not just the permit itself. Most homeowners retrofit for the insurance savings, not code compliance.

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

Simpsonville hurricane retrofit permits — the key details

The practical sequence: obtain a permit from Simpsonville Building Department, complete the work in phases (roof-to-wall straps first, secondary barrier after, shutters/doors last), schedule city final inspection, then hire a licensed SC wind-mitigation inspector to complete the OIR-B1-1802 form. The city inspection typically takes 1-2 hours and verifies fastener spacing, strap placement, garage-door bracing hardware, and secondary barrier coverage. The wind-mitigation inspection follows the same scope but generates the insurance-discount documentation. Both inspectors will mark defects if fastener spacing is off, straps are missing truss bays, or hardware is not rated for design wind speed. Plan for 2-4 weeks from permit pull to final inspections, depending on inspector availability. Once the OIR-B1-1802 is signed, submit it to your insurance agent; most carriers process discounts within 30 days. The discount typically reduces annual premiums by 5-20%, depending on which retrofits are completed and the carrier's underwriting guidelines. For a $1,200/year homeowners policy, a 10% discount equals $120/year savings — recouping a $6,000 retrofit in 50 years, but accounting for insurance-rate inflation, the payback is often 3-5 years in practice.

Three Simpsonville wind / hurricane retrofit scenarios

Scenario A
Roof-to-wall strap retrofit only (1990s ranch, rear gable, Simpsonville historic neighborhoods)
A 1994-built ranch home in central Simpsonville with a gable roof and wood-frame construction (2x6 trusses at 24 inches on center) lacks roof-to-wall connections — a common Simpsonville-era home deficiency. The homeowner hires a structural engineer to design strap placement for 90 mph wind speed (SCBC R301.2.1.1), specifying 1/2-inch diameter bolts at every truss bearing with 3-inch washers and 1/2-inch nylon lock nuts. The engineer's drawings call for 16 straps on the roof perimeter (4 on gable walls, 12 on eave lines) at an estimated cost of $2,500 for materials and $2,000 for labor. The homeowner pulls a permit from Simpsonville Building Department, submitting the engineer's plans and a signed owner-builder affidavit per SC Code § 40-11-360. Permit fee: $110 (base $50 + 1.2% of $4,500 estimated valuation). The city schedules a pre-work inspection (1 week out) to verify truss layout, then the homeowner or contractor installs straps and schedules final inspection. The city inspector verifies fastener spacing, washer sizes, and bolt tightness (pull-test is not required at city final, but the wind-mitigation inspector may spot-check). After city sign-off, the homeowner contracts a licensed SC wind-mitigation inspector ($200) to complete the OIR-B1-1802 form, documenting the strap upgrade and photographing installation. Insurance company grants 8% annual premium discount ($96/year on a $1,200 policy), paying back the retrofit in 52 years — but this home's insurance was at risk of non-renewal due to wind vulnerability, so the retrofit also locks in 5 years of stable premiums (value: $400–$600 in premium avoidance). Timeline: 4 weeks. Total cost: $4,500 retrofit + $110 permit + $200 insurance inspection = $4,810.
Permit required | Owner-builder allowed (SC § 40-11-360) | Structural drawings required (engineer ~$400–$800) | City final inspection + wind-mitigation inspection (separate) | 8-12% insurance discount (5-year premium lock-in) | Total project $4,500–$5,200
Scenario B
Secondary water barrier retrofit (asphalt-shingle roof, decking replacement, 1980s colonial, Simpsonville suburbs)
A 1982-built colonial home in suburban Simpsonville (Woodridge neighborhood area) is due for roof re-shingling. The homeowner elects to upgrade to a secondary water barrier (peel-and-stick ice-and-water shield) under the new shingles per SCBC R301.2.1.2 (Secondary Water Barrier in High-Wind Regions). This work typically requires a permit because it is structural in nature — the barrier is part of the wind-resistance envelope and must be inspected for proper coverage and seal. The homeowner obtains a roofing bid: $8,000 for a 2,200 sq ft roof tear-off and re-shingle with GAF Timberline HD asphalt shingles (3-tab nailed at 6 nails per shingle), plus $1,500 for secondary barrier (membrane applied over 15-lb felt starter course, covering entire roof deck). Total valuation: $9,500. Simpsonville permit fee: $165 (base $50 + 1.75% of $9,500). The city's building department reviews the roofing permit application (standard 3-5 day review), then schedules a pre-tear inspection to verify existing deck condition and confirm secondary barrier specification. During re-roofing, the city may conduct a mid-roof inspection (optional, but recommended to verify barrier sealing at eaves and gable edges). Final inspection verifies barrier overlap, nail pattern, and shingle attachment. The wind-mitigation inspector (separate) then examines the secondary barrier for continuity, seal integrity, and coverage per OIR-B1-1802 guidelines. This retrofit earns a 5% insurance discount (secondary barrier is worth less than roof-to-wall straps in most underwriting models, but still valuable). Timeline: 6 weeks (roof delay common in SC due to contractor backlog). Scenario B showcases Simpsonville's reliance on secondary barrier compliance — inland homes often overlook this, but it is a code-required upgrade in any roof replacement. Total cost: $9,500 retrofit + $165 permit + $200 insurance inspection = $9,865.
Permit required (roof replacement always triggering) | Secondary barrier specification in bid (GAF, Tamko, or CertainTeed brands) | City final + wind-mitigation inspection | 5% insurance discount | Total project $9,500–$10,500
Scenario C
Garage-door bracing + impact shutters (split retrofit, new construction-adjacent home, Simpsonville edge neighborhoods)
A 2008-built home in the Simpsonville edge area (closer to Greenville County unincorporated land) has a standard 9-foot residential garage door with a 1-3/8-inch steel frame and no bracing. The homeowner also wants to retrofit impact-rated aluminum shutters on 6 front-facing windows for aesthetic and insurance reasons. The garage-door bracing requires a licensed SC contractor familiar with SCBC R301.2.1.5 (Garage Doors in High-Wind Regions) — a diagonal brace kit rated for 90 mph wind speed, typically a steel cable or rigid bar system tensioned to 150+ pounds. Cost: $1,200 (materials + labor). The shutters are ASTM D3161-compliant aluminum, powered by hand crank, rated for 150+ mph impact (excess to the 90 mph design wind speed, a common homeowner choice for future-proofing). Cost: $3,000 (6 shutters at $500 each, installed). Total project valuation: $4,200. Simpsonville permit fee: $125 (base $50 + 1.79% of $4,200). Here's the Simpsonville-specific angle: the city's building department does NOT require TAS 201/202/203 impact-testing labels (those are Florida-specific), but WILL require the garage-door bracing to be engineered or certified by the manufacturer, with installation drawings. Many Simpsonville homeowners are surprised to learn they can install impact shutters without Florida-level documentation — a relief compared to Miami-Dade rules, but still requiring a permit and final inspection. The city schedules pre-work inspection to verify garage-door frame condition and confirm shutter mounting substrate (vinyl siding or brick). During installation, the contractor may request a mid-work inspection to verify garage-door brace tensioning (this is optional but recommended to avoid re-work). Final inspection verifies brace security, shutter latching, and fastener pull-out (the city inspector may hand-test fastener tightness). The wind-mitigation inspection documents both upgrades on the OIR-B1-1802 form. Insurance discount: 10% combined (garage-door bracing + impact shutters = significant underwriting relief for wind risk). Timeline: 3-4 weeks (straightforward). This scenario showcases Simpsonville's lower documentation burden vs. Florida — same work, fewer labels, faster approval. Total cost: $4,200 retrofit + $125 permit + $200 insurance inspection = $4,525.
Permit required (structural door bracing, shutter fastening) | No impact-testing labels needed (not Miami-Dade) | Garage-door brace must be manufacturer-certified | City final + wind-mitigation inspection | 10% insurance discount (both upgrades) | Total project $4,200–$4,800

Every project is different.

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The OIR-B1-1802 form: Why it matters more than the city permit in Simpsonville

Many Simpsonville insurance agents are not proactive about mentioning the OIR-B1-1802 form, so homeowners complete retrofits and never learn they could have received a discount. The solution: contact your insurance agent BEFORE pulling the permit and ask which retrofits your policy will discount, and request the agent's preferred wind-mitigation inspector. The agent often has a list of licensed inspectors they trust. Once the city final inspection is complete and photos are taken, schedule the wind-mitigation inspection within 48 hours (while work is fresh and no other trades have disturbed fasteners or barriers). The wind-mitigation inspector will verify the same details the city inspector did, plus photograph each upgrade and complete the OIR-B1-1802 form. The homeowner submits the signed form to the insurance agent, who processes the discount — typically a 30-day turnaround. Simpsonville homeowners in high-wind-risk areas (rural edges, exposed ridge-top homes) often see 15-20% discounts, worth $150–$300/year on a typical $1,200 policy. Over 5 years, this can total $1,000+ in savings, far exceeding the retrofit cost if planned correctly. The key: communicate with your insurer early, confirm the retrofit list, and factor the wind-mitigation inspection into your timeline and budget.

Simpsonville's climate, soil, and unique retrofit challenges

Simpsonville's 90 mph design wind speed (SCBC R301.2.1.1) is significantly lower than coastal SC counties (Beaufort, Charleston County are 130+ mph), so retrofit engineering is less stringent. A homeowner retrofitting in Beaufort would need roof-to-wall straps every 12-16 inches on center; in Simpsonville, every 24 inches is often acceptable. This is a cost relief — fewer straps, lower labor, faster installation. However, the city still requires proper engineering or manufacturer certification, and fasteners must be sized for pull-out testing (city inspector verifies by hand-tightness; wind-mitigation inspector may use a calibrated pull-tester). Simpsonville homeowners upgrading older homes are often surprised by the fastener size: 1/2-inch bolts with 3-inch washers are common, not the 3/8-inch fasteners that might suffice in a lower-wind zone. The city inspector will flag undersized fasteners during final, requiring removal and re-work. This is a Simpsonville-specific gotcha: contractors from lower-wind areas (or those unfamiliar with SC code) often under-specify fasteners, leading to rework delays and cost overruns. Confirm fastener specs with the engineer before bidding, and have the contractor source fasteners early.

City of Simpsonville Building Department
Simpsonville City Hall, Simpsonville, SC (exact address: contact city directly)
Phone: (864) 967-3100 (typical Greenville County municipal line; verify with city directly) | https://www.simpsonville.org (city website; check for online permit portal or application forms)
Monday-Friday, 8:00 AM - 5:00 PM EST (typical municipal hours; confirm before visiting)

Common questions

Do I need a permit for hurricane shutters only?

Yes. Even standalone shutter installation requires a Simpsonville permit because shutters are fastened to the home's structural frame and are part of the wind-resistance envelope. The permit fee is modest ($75–$125), and the city final inspection typically takes 30 minutes. The real value is the wind-mitigation inspection afterward, which unlocks a 5-10% insurance discount. Do not skip the permit and assume shutters are cosmetic — the city enforces this as a structural attachment.

Can I do the retrofit work myself as an owner-builder?

Yes, per SC Code § 40-11-360, Simpsonville allows owner-builders to pull permits for their own homes without a licensed contractor. However, you still need the city permit and final inspections. For complex work like roof-to-wall straps, hire a structural engineer ($400–$800) to design the system; you can then install it yourself or hire labor-only crews. For garage-door bracing and roofing, you may need a licensed contractor depending on the complexity — check with the building department before starting. The wind-mitigation inspection must be completed by a licensed SC wind-mitigation inspector (not the homeowner), so budget $150–$300 for that.

How long does the retrofit permit process take in Simpsonville?

Plan for 4-6 weeks total: 5-10 days for city plan review, 1-2 weeks for pre-work inspection scheduling, 1-2 weeks for construction (varies by scope), 2-3 days for final inspection scheduling, and 1 day for city final + 1 day for wind-mitigation inspection. If inspectors are booked, delays can extend the timeline. Submit complete, sealed plans to avoid rework and re-review.

What if I live in a Simpsonville historic district or flood zone?

Simpsonville does not have a prominent historic district overlay that would restrict wind-retrofit aesthetics (unlike Charleston or Beaufort). If your home is in a mapped flood plain (check the FEMA flood map), you may need additional city approval for certain work, but wind retrofits (roof straps, secondary barrier, shutters) are typically flood-compliant. Contact the city to confirm if your address is in a special-hazard area.

Does Simpsonville offer any grants or rebates for wind retrofits?

Simpsonville does not offer a local retrofit grant program. The MyHome Florida program ($2,000–$10,000 grants) applies only to Florida residents. However, check with your homeowners insurance company for carrier-specific rebate programs — some insurers (Allstate, State Farm) offer retrofit discounts or even partial cost reimbursement for certain upgrades. The OIR-B1-1802 documentation is the key to unlocking these discounts.

What fasteners and materials does Simpsonville require for roof-to-wall straps?

SCBC R301.2.1.1 does not mandate specific fastener brands, but requires 1/2-inch minimum diameter bolts with 3-inch washers and nylon lock nuts, or equivalent hardware certified for pull-out strength in wood (typically 3,000+ lbs pullout per fastener). Common manufacturers: Simpson Strong-Tie, Boral, or Lee L-brackets. Your structural engineer will specify the exact system. Avoid undersized fasteners (3/8-inch or smaller) — the city inspector will reject them.

Is the city final inspection the same as the wind-mitigation inspection?

No. The city final inspection verifies code compliance and is mandatory. The wind-mitigation inspection is optional and must be requested separately; it documents upgrades for insurance discounts on the OIR-B1-1802 form. You must coordinate both — typically scheduling the wind-mitigation inspection after the city passes the final. If you skip the wind-mitigation inspection, the retrofit is legal and permitted, but you forfeit the insurance discount (5-20% annual savings).

What happens if the inspector finds defects during the city final?

The city will issue a Correction Notice listing defects (e.g., fastener spacing off, secondary barrier overlap insufficient, garage-door brace not fully tensioned). You have 14-30 days to correct the defects and request re-inspection, typically at no additional fee. Re-inspection takes 3-5 days to schedule. Plan for 1-2 correction cycles if the contractor is unfamiliar with SC code; budget 1-2 extra weeks in the timeline.

What insurance companies accept the OIR-B1-1802 form for discounts in Simpsonville?

Most major carriers (State Farm, Allstate, Nationwide, SCGHA) accept the OIR-B1-1802 form and offer 5-20% wind-mitigation discounts. Discount amounts vary by carrier and underwriting guidelines. Some regional carriers (Heritage, Universal, SCGHA FAIR Plan) may discount more generously for roof-to-wall straps and secondary barriers than national carriers do. Ask your agent which upgrades your policy will discount BEFORE retrofitting — this ensures you prioritize high-value improvements.

Can I install impact-rated windows without a permit?

No. Any structural or envelope upgrade — including impact-rated windows or doors — requires a Simpsonville permit. The permit cost is modest ($75–$150 depending on valuation), but skipping it risks insurance denial if a claim is filed after an unpermitted window failure. The permit ensures the windows are properly fastened per SCBC R301.2.1 and documented for insurance purposes (part of the OIR-B1-1802 certification).

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 Simpsonville Building Department before starting your project.