Achieving thermal efficient homes with cavity wall insulation

Products Used:	Celotex CW4000
Sector:	Housing

For the traditionally designed Alvington Place housing development located in a stunning position within the Conservation Area of Alvington near Yeovil, Somerset, insulation was needed that could be relied upon to deliver superb thermal efficiency at the right price. Having used Celotex' renowned insulation boards in the past to great success, developers Strongvox Limited opted to use it again on the cavity walls of the scheme.

With a strong track record as a turnkey developer in the West Country, Strongvox Limited design, build and sell their properties with a large emphasis on Local Architecture, traditional materials and fitting in with the surrounding vernacular. Its Alvington Place development proved no exception consisting of a variety of 40 2, 3 and 4 bedroom quality homes, planned in line with regional design and constructed from established materials fitting in perfectly with the beautiful local area.

Strongvox Limited selected 50mm Celotex CW4000 for the cavity walls of the homes at Alvington Place. With 60% of the UK's carbon footprint a direct result of the built environment, providing high performance insulation is crucial to the nation's move to sustainability and provides savings for homeowners in the face of rising energy costs. The use of high performance insulation was also pivotal to Strongvox's commitment to building the most thermally efficient homes.

The thermal properties of Celotex CW4000 have made it a consistently popular choice with architects and specifiers. Made from PIR (polyisocyanurate) with foil facers for improved emissivity, it offers an impressive lambda value of 0.022 W/mK as well as BBA (British Board of Agrement) certification. The boards also hold uniform thermal performance across the product for supremely reliable performance. In addition to excellent thermal performance, Celotex CW4000 has low Global Warming Potential and zero Ozone Depletion Potential.

With a good strength to weight ratio, Celotex CW4000 insulation boards are easily handled and can be cut and shaped onsite with hand tools. Strongvox's operatives placed the boards between cavities and held them in place with clip-ties to create a high performance thermal envelope. As the boards do not trap moisture - unlike fibre and mineral wools - they provide long lasting and reliable performance and are especially suitable for cavity walling, where high levels of moisture can affect the integrity of masonry.

As well as cavity walling, Celotex offers products that can be used in a variety of other applications, including pitched and flat roofs, timber and steel frames and in under-screed flooring.

With approximately 50% of the Alvington Place development complete and families already enjoying their new build homes, the scheme provides well built houses in an attractive rural environment. Benefitting from good value and high performance insulation, the families can boast reduced heating bills and carbon footprints for years into the future.

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:

• BBA certificates - where applicable to the application
• Declarations of Performance
• Health and safety datasheets

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.

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