Donaldson Timber Engineering has seen a flurry of orders for its SIRS roofing system, which incorporates SIPS panels, roof trusses and cassette floors and, most importantly, excludes purlins.

Currently order books are building for SIRS, with orders from Opal Homes for its site in Anstruther in Fife, where SIRS complements Opal’s 'thin joint' system of build, thus bringing together two forms of MMC.  

Another developer, Lomond Homes, is trialling the system on a roof which was too wide for other systems; and the Westbury Partnership has used SIRS on a Coventry where a 'room in the roof' house type was deemed “ideal for SIRS". SIRS is also said to be appealing to self builders, with the most recent order coming from Dorset.

The design of the SIRS system is predicated on the idea of “making things easier” for the builder and the system offers several advantages:  it is simple and quick to build and can reduce erection time by up to 60 – 80%; it gives up to 25% more floor space; achieves long spans; and suits a variety of roof shapes – Dutch Hip, T shape, Gable to Gable; and it also meets all current UK building regulations.

One big player who batted early for SIRS was Persimmon Homes, which trialled the system successfully at its Living I site at Irlam in Manchester, using it in the 'Energy House'.