Wetherby Gateway

The site was a backfilled quarry, and the vendor’s desk study described it as competent made ground. Our own investigation put twelve boreholes across the footprint and found up to 6.2 metres of poorly compacted fill over one third of the site, with the rockhead dipping sharply to the north-east.

That finding arrived before the contract was signed, which is the whole point of doing it early. The foundation design changed from strip footings to 340 CFA piles and the slab from ground-bearing to suspended. It added £1.1m and eleven weeks to the pre-construction programme, and it removed a differential settlement problem that would have appeared about eighteen months after handover.

The superstructure then ran without incident. Steel erection took nine weeks, cladding eleven, and the building was handed over eleven days ahead of the revised date.