Building Control Inspection: Structure
PremiumWhat the BCO checks at the structural stage of your extension: steels, wall ties, cavity barriers, roof timbers, and the pre-plasterboard inspection that catches problems before they're hidden forever.
Do this first:
Cover up your steelwork, wall ties, or roof structure before the building control officer has inspected them and you've created the most expensive kind of mistake: the kind where finished work gets ripped off the walls. Plasterboard stripped. Insulation pulled out. Weeks of progress reversed so an inspector can see what should have been visible when they visited. Forum after forum describes the same pattern: builder skips the structural inspection, work gets covered, the BCO can't sign off what they can't see.
The structural stage inspection is the last time anyone will see the bones of your extension. After this, plasterboard, insulation, and plaster conceal everything. Wall ties, cavity barriers, holding-down straps, steel bearing lengths, insulation depth, fire stopping. All of it gets buried. If the BCO hasn't verified it before it's concealed, it either gets exposed again (at your cost) or it never gets checked at all.
Before the BCO can carry out the structural inspection, all the major structural work must be complete and visible. Your walls must be at plate height with wall ties in place. Your structural steels must be installed with padstones, and any design changes notified to building control. Your roof structure must be framed with the wall plate strapped. The roof covering can be on (some BCOs combine the structural and covering inspections), but the internal side of the structure must remain exposed. No plasterboard. No boarding. No boxing-in of steels.
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