CMYA Finalist

Employer: Willmott Dixon Construction

Project: Gateshead Heights, Harlow Green

Mark Wolverson has proved that it is possible to viably retrofit existing high-rises with sustainable energy systems. He replaced inefficient electric storage heaters in 462 homes with low-cost, low-carbon, smart-metered, district heating systems. Combined with the simultaneous installation of new windows and roofs, the scheme resolved the problem of poor thermal efficiency in six tower blocks where fuel costs were high and fuel poverty widespread.

Mark was something of a replacement himself after the senior manager lined up for the project, who had been involved for several months, left just before the scheme began. Mark had just a few weeks to understand the project, interrogate the programme and design, and get up to speed with the client and the expectations. He quickly discovered that the programme allowed for no slippage of early weather-dependent activities and did not smooth out the labour levels required during the internal works, so trades would be required back onsite just a few weeks after being dropped.

He dealt with the risk by changing the programme to a single handover date instead of sectional completions, and increased the number of concurrent activities to even out labour levels. His creation of programme float ultimately proved invaluable when bad weather early in the works allowed him to absorb a four-week delay, construct plantroom slabs for extra incoming service pits that had been overlooked, and tank the slabs with a gas membrane – all without affecting the completion date.

Rightly foreseeing that gaining access to the flats would be a make or break issue from day one, he ensured residents were visited three weeks, seven days and the day before access was needed to remind them to be in. With no-access rates around 30% nevertheless, his strategy of assigning fallback properties to be available for works to continue if residents were out proved invaluable. Coupled with a right-first-time mindset to eliminate rework (and the repeated access difficulties that would bring), all flats were upgraded without access denial causing timetable overrun.

The many innovations of this scheme – a requirement to secure EU funding – included the installation of 700kW combined heat and power systems and the drilling of 150 150m-deep boreholes for ground source heat pumps. Despite having no experience of the technology, Mark got himself up to speed so effectively that he ended up optimising the system as well as installing it.