• Green Guide 2008 ratings

    Green Guide 2008 ratings

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    Thermal Insulation

    Thermal Insulation ratings are the same for the following building types:
    Domestic, Health, Commercial, Retail, Industrial, Education

    Functional unit for insulation:
    1m² of insulation with sufficient thickness to provide a thermal resistance value of 3 m²K/W, equivalent to approximately 100mm of insulation with a conductivity (k value) of 0.033 W/mK. To include any repair, refurbishment or replacement over the 60-year study period.


    Thermal Insulation is generally a low-density material and only relatively small masses are needed to provide high levels of thermal resistance. Nevertheless, as Building Regulations have improved, and low U values have become more common, the environmental impact of the insulation compared to the impact of the construction element in which it is used has grown.

    Notwithstanding this, the use of insulation in the building fabric will significantly reduce the operational impact of the building over its lifetime. Therefore the benefit of using any of the insulations listed in this guide will outweigh the embodied environmental impact of their manufacture, installation and end of life disposal over the life cycle. This is illustrated by the large number of credits available in BREEAM and the Code for Sustainable Homes for reducing operational CO2 emissions and the single credit available for insulation specifications.

    The basis of the comparison used here is a common thermal resistance so that all the insulations included can be compared on an equal footing.

    How Insulation is assessed in BREEAM 2008

    The latest version of BREEAM has a materials credit for the use of insulation with low environmental impact. Within construction elements, BRE assesses impact based on a typical "generic" insulation, except where the insulation provides a significant additional function. For example a beam and expanded polystyrene block floor where the insulation also provides a structural function; or where the insulation is incorporated into the construction offsite, for example in a composite insulated cladding panel. In these instances, the specific insulation is listed in the element description and its specific impact is assessed for the element where this occurs. The insulation should be assumed to be A+ to calculate the BREEAM insulation credit.

    How Insulation is assessed in the Code for Sustainable Homes and earlier versions of BREEAM

    Within the current version of the Code, insulation is assessed through the use of a pollution credit, GWP of Insulation Blowing Agents. The use of any insulation foamed using a blowing agent with a GWP of more than 5 (e.g. an HFC blown insulation) will prevent the award of this credit. Insulation within elements is assessed on the same basis as BREEAM 2008. However, where an HFC blown insulation is used within a composite for example, the non HFC blown equivalent should be assessed within the elements to prevent double counting.

    Please select the element type of Insulation ratings you wish to review:


    For more information

    Call us on 0333 321 88 11 if you would like to know more, or email enquiries@bregroup.com.