What windstorm certification actually is
Windstorm certification is not a city permit and not an insurance product — it is a state-issued compliance certificate. The Texas Department of Insurance (TDI) runs the windstorm inspection program for structures built in designated catastrophe areas, the Tier 1 coastal counties and specified inland portions along the Gulf Coast.
When a structure in a designated area is built, re-roofed, remodeled, or added onto, a TDI-appointed qualified engineer or inspector verifies the work meets the windstorm building-code standards adopted by TDI. If the work passes, TDI issues a Certificate of Compliance — the WPI-8 (ongoing construction) or WPI-8E (completed construction) — that insurers, lenders, and buyers rely on as proof the structure was built to resist windstorm damage.
WPI-8 vs WPI-8E: which certificate applies to you
The difference comes down to when the engineer gets involved:
- WPI-8 — for ongoing construction. The engineer is appointed before (or early in) the project, inspects at defined stages (plan review, dry-in, fastener, framing, final), and files the WPI-8 when the final inspection passes.
- WPI-8E — for completed construction. The work is already finished — sometimes months or years ago — and the appointed engineer performs a retrospective evaluation of the structure, potentially including testing and engineering analysis, before filing the WPI-8E.
- WPI-8-C — a legacy certificate issued under the former TWIA-administered program. Existing WPI-8-C certificates generally remain valid evidence of compliance, but new certifications today are WPI-8 or WPI-8E.
Who can certify your project
Only engineers and inspectors appointed by TDI as "qualified" may perform windstorm inspections and file the compliance forms. A roofer, general contractor, or building official cannot issue a WPI-8 or WPI-8E. Before hiring anyone, verify their appointment through TDI — our firm works under Texas engineering license #117419, and we are glad to walk you through the verification steps.
The certification process, step by step
Every project follows the same TDI lifecycle, whether it is a residential re-roof or a commercial build:
- Step 1 — Confirm your property is in a TDI-designated catastrophe area (we verify this for you before you spend anything).
- Step 2 — Appoint a qualified engineer. For ongoing work this happens before construction; the engineer files a WPI-1 form to open the project with TDI.
- Step 3 — In-progress inspections. The engineer inspects at required stages and files WPI-2 inspection reports documenting code compliance.
- Step 4 — Final inspection and certificate. When the work passes the final inspection, the engineer submits the paperwork to TDI and the WPI-8 (or WPI-8E) Certificate of Compliance is issued.
Costs and timelines
Residential re-roof certification starts at $500 plus a per-square-foot component; commercial projects start at $800. Rush service (5 days from deposit to TDI submission, with next-day inspection available) adds $500, and certifying completed construction carries a surcharge because the evaluation is more involved. Standard service runs about 14 days from deposit to TDI submission. Use our instant quote calculator for an exact price for your building.
Why certification matters for insurance
TWIA — the Texas Windstorm Insurance Association — is the insurer of last resort for windstorm and hail damage in the 14 coastal counties and parts of Harris County east of SH 146. TWIA will generally not insure a structure in a designated area that lacks a valid certificate of compliance. No certificate often means no windstorm coverage — and that can stall a home sale, a refinance, or a commercial closing. If your project never got certified, the retroactive WPI-8E pathway usually fixes it.