With a target to achieve Code Level 3 accreditation in the Government’s Code for Sustainable Homes without the need to incorporate renewable technologies, a fabric first approach was required. To achieve this outstanding level of thermal performance, the project required high-specification insulation. Therefore the Project Team turned to the UK’s leading manufacturer of PIR insulation, Celotex, and its CW4000 boards.
Located on the site of disused garages, the development comprises four three-bedroom semi-detached houses and a four-bedroom detached house. Designed by Bugler Developments and their consultants Alan Camp Architects for Riversmead Housing Association, the Cundalls Road development was built in a series of projects that provides eighteen new affordable homes across three separate sites in East Hertfordshire.
The scheme consists of traditional brick and block cavity finished with thermowood cladding. With sustainability of utmost importance, as well as providing a simple solution for partial fill cavity walls, CW4000 insulation was specified. Made from PIR (polyisocyanurate) with foil facers for improved emissivity, the product achieves an excellent lambda of 0.022W/mK, helping the project meet the desired U-values. Its exceptional performance also helped ensure the project met Code Level 3 without the need for costly renewable technologies.
Celotex’ CW4000 is the first ever polyisocyanurate (PIR) product to receive approval from Energy Saving Trust – the UK’s leading impartial organisation helping people to save energy and reduce carbon emissions. Meeting strict levels of energy efficiency, the CW4000 boards have also been independently assessed by BRE Global and confirmed as achieving a low environmental impact, through its BRE Approved Environmental Profile. The insulation has also been awarded an A+ rating when compared to the BRE Green Guide 2008, making it the ideal choice for achieving the building’s environmental targets.
Celotex provided 1,000m2 of 100mm thick CW4000 for the main cavity walls, plus an additional 1,000m2 with a thickness of 50mm for the recessed porch areas. The Celotex boards are durable, extremely lightweight and easy to cut to fit using hand tools. Once fitted between the brick and block wall, the boards were secured in place using cavity tie clips, creating a high performance thermal envelope.
Now complete, the new homes at Cundalls Road were successfully delivered five months ahead of schedule, with local families moving in just eight months after construction began. The specification and installation of Celotex CW4000 insulation helped the efficient process as well as providing outstanding energy efficiency that will ensure comfortable living environments and reduced energy bills for many years.