Cundall's Road Case Study

For a new housing development on Cundalls Road, Ware, East Hertfordshire, the choice of materials was vitally important. 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.

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Using CW4000 to achieve code 3 level accreditation on a new housing development

Products Used: Celotex CW4000
Sector: Housing

For a new housing development on Cundalls Road, Ware, East Hertfordshire, the choice of materials was vitally important. 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 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.

Key considerations

When using Celotex products, you need to satisfy yourself that use of the product meets all relevant national Building Regulations and guidance as well as local, national and other applicable standards relevant for your construction or application, including requirements in relation to fire and applicable height restrictions. In addition to the product datasheet, please refer to the following product documents:

Celotex products should not be used in the external walls of buildings over 11 metres in height. Recent changes to Building Regulations mean that only non-combustible insulation or insulation of limited combustibility should be used in buildings of that height.