Silk and Frazier
In order to secure an early competitive tender based upon a known completion date and with scheme design progressing from detail design to production information, it was resolved to invite two-stage bids. The pre-qualifying contractors were required to submit tenders for site preliminaries, defined temporary works, and attendance on all trades with a percentage addition to all sub-let works. A full preliminaries bill was issued together with design information and a detailed priced cost plan. As part of the tender review the contractors were required to confirm their consent to the cost plan or make comments thereon. Two significant and programme-critical elements of the works were the introduction of a full steel frame into the building (all internal floors and a large portion of internal walls were removed) and the creation of a 5m-deep basement to most of the building footprint. The successful contractor, Tarmac, proposed the early installation of the new suspended ground-floor slab cast on grade following internal perimeter piling. This enabled a top-down basement construction excavated from within the new external lift pit and allowed the internal steel frame to be constructed simultaneously. The contractor determined works packages and their appropriate Bills of Quantities, specifications, and drawings were issued to tendering subcontractors. The cost plan was reconfigured to determine a budget for each works package. The external envelope had been completely refurbished as a separate contract.