Building Control Foundation Inspection: What to Expect
PremiumYour BCO must inspect open foundation trenches before concrete is poured. Here's what they check, what 'bottoming up' means, and how to prepare so nothing delays the pour.
Do this first:
Pour concrete into your foundation trenches before the building control officer has inspected them and you've created one of the most expensive mistakes on a domestic extension. The BCO can require you to dig up the concrete, expose the foundations, or commission a structural engineer to assess what's underneath. On forum after forum, homeowners describe the cost and stress of this error. It is entirely avoidable.
The foundation inspection is the first time your project meets the BCO on site. It's also the single biggest scheduling pinch point in the entire groundwork phase. Everything waits for it. Your concrete delivery, your blockwork, your programme. The BCO's approval is what separates a hole in the ground from a foundation you can build on.
Before the BCO can inspect your foundations, two things must already be done. Your building control application must be submitted and approved (or conditionally approved), and you should have received an Inspection Service Plan listing the stages where the BCO wants to visit. Your foundation trenches must be dug, open, and ready for inspection. Do not book the concrete truck until the BCO has seen the trenches and given approval.
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