Eighteen months to demolish a 10-storey block and construct a 100,000sqft turnkey office on a city centre site with no-storage restrictions and painfully difficult access (major demolition work, for example, could take place on Sunday only) is quite a challenge. Add to that late design changes, a three-month holdup in getting the contract signed, and a budget that was even tighter than the site, and you get some idea of the scale of Margaret Conway’s achievement in delivering two months early to an excellent standard throughout.
With planning consent gained on a 120,000sqft, 10-storey block, she worked with the client’s budget to lose a storey on the new build, taking out a further mezzanine level to hold down the costs. Her removal of rooftop plant reduced the building height to below 30 meters, saving the client £500,000 by eliminating the need for a sprinkler system.
Rather than piling through the existing raft foundation, she instructed further site investigation to establish the ground’s bearing capacity. The survey told her enough to be able to supplement the existing raft instead as a spread foundation for the new superstructure, exploiting the large subfloor voids that had been found. As with most structural redesign, it demanded extensive design management and consultation among numerous parties on the construction manager’s part; the reward in this case was a £750,000 saving.
She analysed the use of mast climbers versus scaffold, and concluded the latter was undoubtedly more economic. She then captured the cost gains by coming up with a workable fully boarded design across 16 lifts rather than the maximum seven envisaged by the scaffold contractor.
When the structural engineer flagged up a possible 40mm of movement at the slab edge from the live load deflection and concrete shortening, it shot down the traditional means of supporting large spans of curtain walling at alternating floors. Undaunted, Margaret led the solution of suspending the entire curtainwall from the top of the building, with movement accommodated at the bottom of the screen.
By breaking each floorplate into two zones, she completed much of the fit-out in advance of the elevation-based facade installation. The central core and the meeting rooms were then fitted out independently of the facade and the rest of the open-plan floorplate.
With repeat business on the mind of a main contractor making its first appearance in Northern Ireland for nearly a decade, not to mention its first public sector contract for 10 years, Margaret put muscle into the quality management. She simplified the snagging process and reduced paperwork by introducing Aconex Field software that allowed the professional team to snag onsite and send out contractor-specific snagging lists online. Dovetailing with the project’s document management system, it proved so successful it is being rolled out across all McAleer & Rushe projects.
Late design changes came along. For example, a requirement for 950 workstations rather than the originally specified 730 set the design programme back by nearly four months. Margaret’s immediate response of design workshops created the new layouts and amended the MEP drawings fast and efficiently.
Her delivery achievement is superb – even more so given that it was her first project management role on the contractor’s first level 2 BIM scheme. Her hard work and organised, methodical approach was key to success – and to the client’s award of another large joint-venture contract.