Thousands of square metres of Energysaver GRP composite rooflights from Brett Martin Daylight Systems have been used in the construction of Waitrose’s first national distribution centre at Magna Park in Milton Keynes.
Developed by IDI Gazeley and built by McLaren Construction, the new facility includes a 940,000ft2 roof, 15% of which is made up of Energysaver rooflights. These were specified to allow the entry of maximum daylight levels and reduce energy demands at the new building.
Working closely with supply chain partners Kingspan, Premier, SFS Intec and Brett Martin, the project’s full envelope contractor FK Group carried out extensive testing at pre-construction stage to challenge industry best practices and ensure the most efficient fixing techniques. This resulted in a new method of fixing for the Kingspan composite panels and the Energysaver rooflight units being developed to deliver maximum airtightness and minimise any risk of water ingress. The insulated roof panel system and rooflights were then systematically installed by FK Group in a fast-track nine-week programme.
Bill Hawker, technical director at Brett Martin Daylight Systems, said: “A significant number of subtle changes to product specifications and the installation process combine to represent quite a departure from standard practice, delivering significant performance improvements that have now been proven in practice.”
On completion, an airtightness test demonstrated that the building achieved a result of 0.51 m3/hr/m2 – exceeding the original challenging target and the best practice required by Building Regulations Part L2A. Based on this expected performance, the building will achieve operational savings in the region of œ7,500 and 39,000kg of CO2 per year.
Steve Hall, construction director at FK Group, said: “Our specification of higher performance products at the Waitrose National Distribution Centre has demonstrated that this approach can deliver a more cost-effective final solution. As a result this innovative new specification has been adopted as standard practice for all our forthcoming logistics and distribution projects.”
Brett Martin’s Energysaver composite panel rooflights are triple skin, factory-assembled insulating rooflights (FAIRs) for composite roofs, and are manufactured from GRP. Designed to the same depth as the composite roofing system, Energysaver’s flat liner panel sits flush with surrounding metal panels for excellent aesthetics and a neater internal appearance. Delivering U-Values from 1.9W/m2K down to 0.9W/m2K, they offer high quality diffused natural daylight, thermal performance and ready-to-fit convenience for wide-span buildings.
The specification of Brett Martin’s Energysaver composite panel rooflights also helped FK Group to meet the client’s criteria for an extended warranty. As the building lease is divided into two 15-year periods and not the standard 25 years, the increased thickness of the rooflight offered FK Group additional flexibility to deliver improved life expectancy and minimise maintenance requirements over the building’s lifetime.