Run the structural wind-load check

MCS requires you to show that the mounting is safe against wind uplift (EN 1991-1-4 / MCS 012). Assuming it is safe is not enough. The check uses the arrays in the variant's 3D plan. For each fixing, it compares the wind uplift with the fixing's pull-out resistance, with a safety factor applied. There are five steps: location, roof sides, mounting, result and report.

Before you start

• The project must belong to a UK client.
• Check the project address. The check reads wind load, distance from the sea, altitude and snow zone from the address, so you don't enter them yourself.
• Know the site's terrain and topography. These are the only location inputs you enter by hand.
• Draw the arrays in the variant's 3D plan first. The check only keeps roof sides that are still in the variant's current 3D plan.
• Use a variant without an active signature. You can only save roof sides while the variant is unsigned.
• Stay inside the supported range: wind zones 1 to 3, ridge height 5 to 25 m, roof pitch 5 to 45°.

Run the check

1. Open the offer and go to the Planning view.
2. In the Solar planning area, open the MCS structural check.
3. On the location step, review the wind load, distance from the sea, altitude and snow zone filled in from the address.
4. Enter the terrain and topography.
5. On the roof sides step, enter the roof sides.
6. Save the roof sides.
7. Work through the mounting step.
8. Read the result. For each fixing, the result compares the wind uplift with the fixing's pull-out resistance, with a safety factor applied.
9. Finish with the report step.

The result is saved against this offer variant as a versioned MCS structural record, so you don't have to recompute it later. Re-run the check if you change the array or the fixing plan.

Things to know

• Redrawing an array removes its roof side. Each roof side is tied to its array's geometry in the 3D plan. If you redraw the array, go back to the roof sides step and check that roof side again.
• Saving location details changes nothing else. The line items stay as they are, and you can save location details on a signed variant.
• Location data is fetched once per project. Wind load, distance from the sea and snow zone are looked up once and kept for the project. Altitude comes from the project's location.
• The looked-up wind and snow data only fill in the location details. This data doesn't size materials or change your roof-side entries.
• Check snow load separately. The check only compares wind uplift with pull-out resistance for each fixing.

Last updated on November 9, 2026