These are measured on the basis of their embodied energy and toxicity environmental impact, and scarcity and technical performance whilst being commercially viable.
We take great care with our material selection process and continually review what we use and how we use it. As an example, we recently assessed the impact of our pipework and decided on using stainless steel where metallic pipework is necessary. Stainless steel requires more energy to make per kg than standard steel, however pipes have a lower overall embodied energy per unit length as wall thicknesses are much thinner and therefore lighter. For instance for 150 mm diameter pipe, stainless steel can generate up to 298 mega joules less energy per metre than steel, equivalent to 9.17 kg anthracite coal. Long-term system efficiency and service life are all assured due to the corrosion-resistant nature of the pipework.
Where possible and technically and aesthetically correct, we actively promote the use of plastic pipework, which is available in a wide range of types, each with its own characteristics. We select and design carefully so that we optimise their benefits, which include fast installation, zero scrap value, a long corrosion-free life and long-term system efficiencies.