Foundation slab: price per m² in 2026, process and common mistakes

The foundation slab carries the whole house for decades — and it is the one structure you can never repair once the build is finished. So it is the last place to save money. The good news: a quality slab does not cost that much more than a botched one.

How much does a foundation slab cost in 2026?

The price covers excavation, strip footings, gravel bed, in-slab services (drainage, conduits), damp-proofing and radon protection, reinforcement and the pour. Prices excl. VAT.

Step by step

1. Setting out and topsoil strip.
2. Footing trenches below frost depth (80–120 cm).
3. Pouring the footings and laying permanent-formwork blocks.
4. Drainage runs, conduits, penetrations — everything that belongs in the slab goes in now.
5. Gravel bed compacted in layers.
6. Damp-proof and radon membranes.
7. Mesh/reinforcement and the slab pour, vibrated, to ±5 mm flatness.
8. Curing — watering, protection against rapid drying; full strength after 28 days.

Most common mistakes

• Underestimating radon — the radon survey is mandatory and cheap; remediating a finished house is extremely expensive.
• Poorly compacted bed — the slab settles and cracks.
• Forgotten penetrations — drilling a finished slab later is money wasted.
• Pouring in frost or heat without precautions — the concrete loses strength.
• No geological survey on slopes and clays — the most expensive surprise of all.

A slab for VELOX, brick and timber frame alike

The foundation slab is universal — we build brick, VELOX and timber-frame houses on the same slab. Only the anchoring details and thickness change per the structural design. Our online calculator gives you an indicative price for the whole build including foundations; the itemised project budget is free.