Do not select a pergola from a generic wind rating alone. Provide the exact site, locally required design criteria, terrain and exposure, elevation, module dimensions, roof type, post layout, wall connections and foundation information. The supplier can then identify a product starting point, while qualified local parties confirm structural suitability, foundations and approval requirements.
Information needed before structural review
Exact location
Country, city and site coordinates where possible, not only a regional market name.
Design criteria
Wind, snow and other loads required by the local engineer or authority.
Exposure
Open coast, rooftop, urban shelter, valley, hillside or surrounding buildings.
Geometry
Every bay's width, projection, height, roof direction and connected-module layout.
Supports
Post positions, wall mounting, shared beams and any requirement for fewer columns.
Foundations
Available slab, footing or supporting structure and who will design the connection.
Catalogue size versus site approval
A maximum single-module reference describes a catalogue selection boundary, not universal approval. The same 4 × 6 m module can behave differently on a sheltered ground-level patio and an exposed rooftop. Connected modules also change load paths, shared supports, drainage and movement.
Use catalogue sizes to shortlist models. Use project drawings and local criteria to verify the actual layout. If the supplier cannot explain this distinction, the quotation may be missing important assumptions.
Questions to send the supplier
| Question | Why it matters |
|---|---|
| Which model and module arrangement are you reviewing? | Prevents a rating for one system being applied to another |
| Which wind, snow and exposure inputs were assumed? | Makes the basis of the recommendation visible |
| Are louvers open, closed or in another position for the stated condition? | Operating assumptions may affect the review |
| Which posts, beams, connections and foundations are included? | Separates product supply from local supporting work |
| What remains for the local engineer or authority? | Clarifies responsibility before order approval |
Snow and water are different checks
Snow loading concerns structural demand and local design criteria. Rain management concerns louver closure, gutters, drainage routes, post outlets and the site discharge. A product described as rain-managing should not automatically be assumed suitable for an unspecified snow condition.
Warning signs in a quotation
- A single wind number with no model, module size or operating condition.
- No distinction between overall project size and one structural bay.
- Foundation or wall capacity assumed without site information.
- A rooftop treated the same as a sheltered patio.
- Catalogue dimensions described as approval for every location.
- No written list of engineering assumptions and local responsibilities.
This guide does not provide a wind or snow rating. Final structural design, foundations, connections, permits and installation compliance must be established for the project location by qualified parties.
Technical review: JY Home Shade factory product team · Last reviewed: 28 August 2026
Send the site criteria with your layout
Include location, dimensions, height, module plan and any wind or snow criteria supplied by the local project team.