An increasingly important consideration as new
building techniques are developed to supply the buildings that meet
the government requirements of low and zero carbon buildings is the
sustainability of building materials used in the construction from
‘cradle to grave’ or even cradle to cradle.
Designers should consider the total
environmental impact of production and use, including the
extraction and supply of all raw materials, the manufacturing
process, delivery to site as well as the expected service life of
the material.
The first step in evaluating these impacts is
to carry out a Life Cycle Analysis. International Standards (ISO
14040 series) exist for the collection and analysis of life cycle
data. These standards allow for differing approaches and
interpretations, and whilst this may be completely justifiable and
understood by life cycle analysis experts, it can cause confusion
for building professionals who are trying to make judgments on the
sustainability of the materials they specify. What is needed is a
common approach to life cycle analysis of construction materials
and this is provided by the BRE Green Guide. The ratings from the
Green Guide are used to inform the materials sections of the Code
for Sustainable Homes and all BREAM assessments and are generated
from data collection certified by the BRE and a single common
interpretation methodology.
The BRE Green Guide is available at http://www.thegreenguide.org.uk/.
A hard copy will follow in the second half of 2008. This carries
ratings that classify insulation materials and elements of
construction in to six bands: A+ to E.
Mineral wool – complete sustainability
Mineral wool products will achieve excellent
ratings in the Green Guide. The raw materials used in the products’
manufacture either come from recycled sources such as bottle glass,
or are extracted from naturally abundant sources such as sand or
dolomite stone.
Consumption of energy and other materials is minimised in the
manufacturing process to allow the product to have environmental
profiles similar to or better than many natural products such as
sheep’s wool and hemp. In fact, the energy and CO2 saved
by mineral wool can be hundreds of times that used in manufacture
of the product. All Knauf Insulation’s manufacturing plants operate
under Certified Environmental Management Schemes which set out
steps for continual assessment and improvement of environmental
performance.