A new retirement home development in Milton Keynes contains a total of 184 self-contained apartments and presents a stylish appearance to the outside world: its architecture crowned by an unusually articulate roofscape. While the seven metre high pyramid form to the front of the building is the most dominant feature, much of the complexity to the timber engineering now goes unseen as a mixture of metal decking and tiling completes the covering of the prefabricated structure.

In addition to the variations in pitch and span of the different truss configurations, the roof zones also contain a variety of mechanical plant, requiring Robinson Manufacturing to incorporate maintenance walkways into many of the truss profiles. The company also made use of the very versatile “Roof & Truss” Gang-Nail® Software package to design wind girders into the assembly. This  means that rather than having lots  of wind bracing included in the main superstructure, these heavy duty timber girders in the roof absorb and distribute loadings exerted on the aluminium alloy frame that forms the storeys below.

Then because the home in Milton Keynes is designed to extra care as well as Lifetime Homes standards, it was also necessary to ensure the ceilings of the top floor apartments were strong enough to support hoists. In fact the factory produced trusses – with their bottom chords and other members manufactured using TR 26 stress graded timber – represent an ideal structure into which to retro-fix such substantial equipment.

The Design Manager for Willmott Dixon, Kim Robinson, comments: “The roof was relatively complex and as a sub-contractor providing an integral part of the structure, Robinson became a crucial member of the design team for the project. The company did a magnificent job in the analysis and providing the necessary details. And when we reached the construction stage, the deliveries came in on schedule with very few problems to resolve.

“In addition to incorporating a lot of the wind bracing, as a requirement of Lifetime Homes legislation the design for the roof and intermediate floors had to take account of the need to install hoists at a later dates. This requires making the supporting timbers strong enough for the extra load and also providing for the hoist track to pass through the wall between the bedroom and the en-suite bathrooms, all of which was taken care of.”

Robinson Manufacturing Ltd in fact supplies clients across the construction industry in sectors such as education, retail, leisure and commercial as well as working for the majority of the UK’s leading housebuilders.