Important Information: For all updates and Celotex announcements since June 2017, please see the links below...  See more

Declared lambda values - Read more >

5000 Class 0 testing - Read more >

Rainscreen cladding & RS5000 - Read more >

Howgill Skies, Cumbria

A Cumbrian Homes development containing 12 new properties has been designed and built to the latest standards, whilst still maintaining the traditional look and feel with local natural stone with the help of Celotex Energy Assessment Service.

U-value Calculator
Start your U-value calculation >
Use the calculator

PIR insulation for a high standard specification housing project Cumbrian Homes

Products Used: CW4000
Sector: Housing

IMPORTANT: We have recently identified a compliance issue relating to our calculation and testing of the lambda value of products in our 4000 and 5000 range and the Crown-Bond and Crown-Fix products within Crown Flat Roofing range. Please note that CW4000 and GA4000 manufactured after 15 December 2017 will be marketed from January as Celotex CW3000 and GA3000 with a declared lambda value of 0.023 W/mK. To read the full statement please visit the Celotex website homepage.


Project Name: Howgill Skies
Main Contractor: Cumbrian Homes
Energy Assessor: Celotex Energy Assessments
Celotex Solution: CW4000 and GA4000
Application: Cavity Wall, Pitched Roof and Floor

The Objective

Located close to one of the South Cumbria's most picturesque market towns, Sedbergh, Cumbrian Homes’ Howgill Skies development will contain 12 new homes. Designed and built to the latest standards and finished in local natural stone, a high standard of specification is common throughout the development – making the homes the most energy efficient the developer has built to date.

The Challenge

New homes developer Cumbrian Homes required high performance insulation for its new 12 home development to achieve target U-values of 0.26 W/mK in the cavity walls and 0.21 W/mK in the pitched roofs – whilst reducing the amount of insulation required and subsequent costs.

The Solution

Appointed to review the project’s cavity wall requirements, Celotex Energy Assessments (CEA) and the Celotex Technical Centre worked closely to produce thermal performance calculations that would achieve space-saving requirements whilst simultaneously delivering improved U-values.

After running comparative Standard Assessment Procedure (SAPs) calculations, CEA was able to change the previously specified full-fill external wall insulation to Celotex CW4000 partial-fill solution – with 3,000m2 supplied in a thickness of 50mm. Meeting strict levels of energy efficiency, CW4000 has been awarded an A+ rating when compared to the BRE Green Guide, making it the ideal choice to meet and exceed the building’s sustainability targets with improved U-values of 0.24 W/mK.

Using the results from thermal modelling, CEA was also able to model the U-values for the pitched roof insulation to achieve the same values as previously specified with fewer materials and reduced costs. Installed between the rafters, 50mm and 80mm thick Celotex GA4000 was specified to achieve a U-value of 0.21 W/mK.

As a result of the new partial fill cavity wall and pitched roof insulation specification – as well as the installation of 100mm thick GA4000 in the floors – Cumbrian Homes was able to meet its energy efficient requirements with a high performance insulation solution.

The Outcome

Celotex was appointed to review the cavity wall requirements at Cumbrian Homes’ Howgill Skies development in South Cumbria. Set to use full fill insulation to meet the 2010 regulations with a fabric first approach, the company was able to reduce their requirements by increasing the standards on thermal bridging.

After running two SAP calculations – one with full fill and one using partial fill – Celotex recommended a high performance solution which delivered a reduction in insulation levels without the need for renewables. Utilising its ability to offer a service on thermally modelling, Celotex managed to adjust their thermal requirement for the cavity with the specification of Celotex CW4000.

With its quick and efficient sustainability services, Celotex removed the hassle from the contractor whilst delivering the cost optimal insulation solution. With the specification of Celotex CW4000, Cumbrian Homes was able optimise costs and make significant savings on the overall construction programme.