Southwest Environmental Limited

What is the Green Guide for Building Materials?

The Green Guide for Building Materials is a set of detailed fact sheets for building materials and construction methods that has been assembled, by the BRE, and they are a key part of achieving good ratings under sustainability schemes such as BREEAM and the Code for Sustainable Homes

Green Guide Ratings

To the left we can see an extract from the green guide to "External Wall -Block Work Cavities" and we can see that some walling systems are better than others A+ or A, so for a higher rating under an accredited sustainability scheme such as BREEAM, you might opt for an A+ system.

But how are these Green Guide values decided.

Green Guide Life Cycle

Each green guide system is put through an assessment process as described to the left, which a form of LCA.

You can appreciate that a materials which are complex in nature, will have very complicated process trees. The assessment is based on LCA and relates to "functional units" of products such a a square meter of flooring or walling or roofing.

At each stage of the assessment the material impacts  are measured and converted to a qualitative value.

Rating Elements

These separate impacts of the product can be seen to the right.

Climate Change on this walling system does not make an A+, this may be due to the high carbon floor print of elements of the walling system such as the bricks, of concrete blocks.

We note at the bottom of the rating list there is the carbon foot print which is a quantitative value. If we compare this value of 68k g over the deign life of the walling system, compared to a timber frame method which creates 42 kg of C02 per functional unit we can see that although both systems are rated A+ there are still significant differences in carbon footprint.


Handy Links (You will need to Log in to the BRE website)

- Green Guide Ratings

- Green Guide Methodology Document

If you would like to discuss sustainability issues related to you particular project then please pick up the phone or send us and email.