Consultant to the oil and gas industry Gaffney, Cline & Associates' picturesque campus at Bentley, Hampshire, was bursting at the seams. A third storey addition to the block housing its technical department was commissioned just over a year ago.
GCA's brief was for flexible space with large open areas for meetings, at a cost of £0.5M or less.
The existing two storey building was a reinforced concrete structure dating from the 1960s, providing a floor plate of 465m2. It had never been intended to carry a third floor.
The extension had to be lightweight and, though carried on the concrete frame of the building beneath it, needed to interfere with the existing structure as little as possible. A cross-braced steel framed structure with floor-to-ceiling glazed walls has been erected.
Architect for the Bentley Hall project John Wright wanted, from the outset, to run the job as an M4I demonstration project. As a Construction Industry Council executive board director he was keen to explore practical ways of achieving objectives set out last year by Sir John Egan in Rethinking construction.
The job was carried out using a management form of contract, selected because it established working relationships that were sympathetic to partnering. The client, architect and main contractor assumed lead roles in the partnership established at the project's outset.
Modern Design Group invited four contractors, including Willmott-Dixon, to tender for the technical block extension. All declined on the grounds that margins on a £0.5M job were too minimal. Wright was forced to call in a favour to bring Willmott-Dixon on board.
Willmott Dixon project director Don Bowles explains: 'It's easier to cut time and cost on big, high cost projects. Savings on a small project will only impress the client.' But recognising client satisfaction is one of M4I's principal thrusts, he conceded: 'At the end of the day, the client will be as impressed if we're making savings of thousands on a small job as millions on a big one.'
All subcontractors were treated as partners and selected first for what they could do, with cost considerations second. 'We went out to subcontractors we believed could do the job and with which we already had a relationship,' says Bowles. 'We gave them all the information we had at that stage and then interviewed the teams they proposed to put on the job. Decisions were made without testing financial proposals at that stage.' Subcontractors and suppliers selected were Built Environment Engineering, responsible for design and delivery of the mechanical and electrical engineering contract; Hawk Engineering for supply and fixing of structural steelworks; Rhinetech for glazing; Apex Roofing for sourcing and installation of roof cladding. Single ply UPVC membrane roofing was supplied by Alwitra.
All parts of the supply chain were brought together during the design phase to resolve interfaces between trades before the project went on site. Pre-planning was used to shorten the critical path during construction, and in so doing bring down overall construction cost. Detailed design started in October last year and the project went on site on 1 June this year. Completion was on 4 October.
Supply chain integration was also favoured for anticipated savings on specification. 'We started by taking a generic view of things rather than being product specific, leading to the most appropriate product being used,' says Wright. 'Architects and M&E contractors in particular are normally very product focused.' Other players were able to identify equivalent products that performed better or cost less than those the architect would normally have selected.
Partnering enabled the design and construction team to quiz the client about what it really, really wanted, leading to an end product that was 'fit for purpose' rather than over-spec. Fees and profits were ring-fenced. Savings were to be equally shared, with the first £10,000 going to the client.