Sustainability: Environmental Impact of Materials

The production, use and disposal of building materials can account for significant amounts of energy and resources, both within the UK and internationally. One way of assessing the impacts is to consider life cycle analysis (LCA) , an approach that considers the performance of materials and construction elements based on a range of environment impacts from ‘’ cradle to grave’’. The most widely used methodology is that developed by BRE in consultation with industry, and used in the Green Guide to Specification.

The Green Guide to Specification provides over 1200 specifications, including many that apply to Lignacite masonry construction, for use in various building types.

A rating system has been derived that presents extensive quantitative data for materials in a relatively straightforward way. This is based on a rating system of A+ to E, with A rated constructions having the least overall environmental impact.

When buildings are subject to a BREEAM or a Code for Sustainable Homes assessment, the materials design category considers the environmental impact of materials. Credits are awarded according to the Green Guide rating as follows:

There is a mandatory requirement in the Code for Sustainable Homes that at least three of the five elements (Roof, External walls, Windows etc) achieve a relevant Green Guide rating from The Green Guide of A+ to D.

Some care and judgement is required when selecting a suitable rating to ensure that other design requirements can be met or are not compromised. To place the ratings in some context, the operational impacts of buildings far outweigh the embodied impacts due to materials production and construction by a factor of about 9:1. Other important design aspects consider may include:

• Appearance
• Cost
• Durability including service life
• Technical performance (acoustics, fire, structural and thermal requirements)
• Buildability
• Operational issues (including the benefits of using high mass materials)
• Maintenance

Ratings that can be used to assess constructions using Lignacite’s products can be found in the Green Guide to Specification www.greenguide.org.uk. These provide a number of blockwork specifications for various building types, based on generic descriptions of blocks. These include ratings for external, internal and separating walls and for beam and block flooring. The following table links the product brands of Lignacite Ltd to these general descriptions.