Thermalite® blocks and sustainability
The manufacturing of Hanson’s Thermalite® range and services is designed to promote sustainability, before and after the product leaves the factory.
To be environmentally sustainable, a product needs to be manufactured and used in such a way as to minimise its impact on the environment. This is a key issue confronting the construction industry and commands construction solutions that minimise the consumption and use of natural resources.
At Hanson, we recognise the impact that we can have on the environment, so we manage all activities to maximise our contribution towards the protection of the environment and the preservation of natural resources.
Reduction, re-use and recycling
The Thermalite® range of aircrete blocks is made from up to 80% recycled materials. Reduction, re-use and recycling are the only really green solutions to the environmental impact of waste. Wherever possible, recycled materials are used in the manufacture of Hanson’s products, thereby reducing the use of primary aggregates.
Pulverised fuel ash
Up to 80% of the material used in Hanson’s Thermalite® blocks is pulverised fuel ash(PFA). This is a by-product from coal burning power stations, which is both stable and environmentally friendly.
A strict waste minimisation scheme is operated during manufacture. All waste is either crushed and recycled into the next mix, used in other concrete products or as an aggregate bulk fill replacement in road construction.
The micro-cellular structure of the Thermalite® product offers remarkably high thermal insulation and, consequently, lowers energy consumption for the heating of buildings. The finished product also contributes to waste reduction – Thermalite® blocks are made to high dimensional tolerances and can be easily and accurately cut to reduce waste on site.
Contributing to energy efficiency
Hanson also operates a modern transport fleet, which, when combined with the lightweight Thermalite® product, ensures that energy consumption during haulage is
The Thermalite® product provides no direct pollution risk to water or air. The stable and inert waste materials can be safely used as land infill where recycling is not feasible.
Life Cycle Assessment
Thermalite® was the first aircrete block to have its Life Cycle Assessment (LCA) data independently reviewed and to be awarded Certified Environmental profiles by BRE Certification. For many years, the Building Research Establishment (BRE), through its Centre for Sustainable Construction, has been encouraging the use of Life Cycle Assessment (LCA), to allow architects, builders and clients to make informed environmental comparisons between construction products.
LCA is a method that measures the environmental impact of a product by assessing the energy and materials used and released to the environment over its full life cycle. LCA results are presented in the form of an Environmental Profile.
Thermalite® was the first block in the UK to receive a Certified Environmental Profile and Ecopoint score from the Building Research Establishment (BRE). When used in an external wall, Thermalite® products achieve an “A” rating in the Green Guide to Specification.
To improve the usefulness of the environmental data and make it easier to understand, BRE has developed Ecopoints – a method of ranking and scoring different
environmental impacts. Ecopoints allow a wide range of environmental impacts (e.g. energy use and mineral extraction) to be compared using the same measure.
The lower the Ecopoints score, the lower the environmental impact. As a benchmark, it has been determined that 100 Ecopoints are equal to the impact of one UK citizen on the environment for one year. A tonne of Thermalite® equates to just 1.9 Ecopoints.
Putting Ecopoints in context
At its simplest level, the profiling method can assess the impact of a single building product, such as blocks. However, to make valid comparisons, designers need information about a building element, such as a wall.
A building element is likely to be made up of several products (such as bricks, blocks and mortar), so Environmental Profiles take this into account by adding together the contribution of the component parts, allowing comparison between one construction element and another.
The BRE’s Certified Environmental Profiles enable manufacturers to demonstrate the credibility of their products. They also help designers and specifiers identify materials that will best fulfil a sustainable brief. The pie chart opposite illustrates the relative significance of various components of a wall. The chart shows that Thermalite® blocks contribute less than 20% of the total environmental impact of a wall construction.
Thermalite® was the first aircrete product to be awarded the coveted environmental manufacturing standard, BS EN ISO 14001, for its manufacturing locations. Thermalite® is also the first block in the UK to receive a Certified Environmental Profile and Ecopoint score from BRE.
The Ecopoint score translates into a ‘Green Guide’ rating of ‘A’ (when used within an external wall element). This can be used to obtain credits in BREEAM and EcoHomes.