Construction Products Association SBE0134

Written evidence submitted by the Construction Products Association


Who we are

-              The Construction Products Association (CPA) is the umbrella trade association for UK-based manufacturers of construction products.  Its members comprise companies and trade associations.  The sector is worth over £55 billion per year and employs over 300,000 people in over 20,000 companies across the UK ranging from large multinationals to SMEs. 

-              The Association is material and product neutral and has membership from across all materials – glass, ceramics, wood, steel, cement, plastics, metals aggregates as well as many product groups – doors, roof tiles, windows, insulation, drainage, heating and bathroom appliances plus coating, adhesives and sealantsOver 65% of the construction products used in construction in the UK are manufactured in the UK.

-              We share the urgency of the need to address the climate emergency and for society to decarbonise quickly.  Manufacturers must play their part in helping to lower the impact of our built environment on the climate and other environmental emergencies. Manufactures have impact in two ways – from the processes to create the construction product, and by the products they create that deliver the performances required within a building structure.  We are familiar with the Paris Agreement, the UK Climate Change Act, the Climate Change Committee carbon budgets, the numerous Net Zero strategies and initiatives emanating from government, and have worked for many years on the formal standards for assessing sustainable impact of construction works including construction products.

-              A number of our member trade associations and companies will be making their own detailed submissions to this Call for Evidence, so we will confine our comments to key points.



-              There are a number of terms that the inquiry uses in its Introduction and TORs that would be useful to tease out and to clarify their meaning.  It is also possible that different communities of experts use the same terms but with different meanings.  The following are mentioned in regard to materials and products by the Inquiry:


-              Other terms refer to the building level, or even a sustainable built environment (implying more than one building perhaps a new development).  


-              It is not always clear therefore whether the primary focus is how do we deliver a low carbon built environment (or sustainable built environment), or whether the focus is on nature-based materials and the size of the opportunity of construction products that are made primarily from materials that are grown and harvested in some way.  There are perhaps some underlying assumptions emerging from the questions asked that will need further exploration given that all construction products will have an environmental impact and this needs to be measured by a life cycle assessment.


Building Structures - Fit for Purpose


-              We are assuming that the inquiry is keen to better understand how to arrive at the lowest carbon solution for the structure intended - be it a school, home, hospital, station etc. 


-              A building must be fit for purpose and to meet the necessary Building Regulations and be safe, thus issues relating to structural performance, durability, integrity and safety are essential.  Carbon will need to sit alongside these as a required performance for the building to meet.  There will be no point in choosing a very low carbon option if it is not fit for purpose or is unsafe.  Rails will need to be made of a durable hard wearing material and tunnels will need to stay open and not collapse; within those parameters what are the lowest carbon options now in the 2020s, and is innovation going to deliver the Net Zero options in the 2030s and beyond.



Whole life carbon assessment of a building-


-              The level at which a carbon assessment should be made is at the building level.  The product is the home, school, office etc and we need to seek the lowest carbon solution.


-              Any proposed building (and we include infrastructure in this) needs to have a whole life carbon assessment carried out to determine what are the lowest carbon options to deliver the overall performance required. 


-              An essential point is that whole life carbon is made up of both the embodied carbon and the operational carbon of a structure over its life cycle – for buildings this is assumed as 60 years and for infrastructure as 120 years (though a different time scale can be declared in the assessment).  This is a key issue and we are aware of a great deal of muddled thinking on this topic in the literature; largely we believe because many in the wider construction industry are unfamiliar with the appropriate standards.





Standards exist for assessing sustainability performance and embodied impacts including embodied carbon


-              Formal standards are available to calculate the whole life carbon of a building, this is EN15978, and for infrastructure is prEN17472 (to be published in Jan2022).  


-              The embodied carbon of a construction product is calculated as part of a life cycle assessment methodology (lca)The life cycle assessment methodology for construction products is defined in the standard EN15804 and produces an Environmental Product Declaration (an EPD).  The data in an EPD needs to be assessed at the building level using the standard methodology EN 15978. 

-              Both EN 15978, prEN17472 and EN15804 are part of the CEN TC 350 suite of standards for assessing the sustainability performance of construction worksThe work on standards started in 2004, with a steady stream of standards published thereafter, some of which have now gone through revisions. The British Standards Institution (BSI) convenes Committee B/558 which reviews and contributes to the development of these standards both at CEN and ISO level.  The standards can be purchased from the BSI.  It is regrettable that these standards are not more widely known amongst the wider construction sector. 

-               The assessment of embodied carbon is technically described in the EN15804 standard as the impact on global warming potential and is measured in kg CO2 equivalent per reference unit.  Equivalent means it relates to all greenhouse gases, as gases such as methane are greatly more potent as a greenhouse gas than CO2.

Consideration of the wider range of environmental impacts, not just carbon

-              A life cycle assessment includes assessment against other environmental indicators in addition to embodied carbon.  Ideally all indicators need to be assessed, otherwise there is the possibility of unintended consequences – e.g. something might be less carbon but much higher in air pollutants (diesel cars being a recent example), or less carbon but discharges high pollutant load to water courses.

-              If we are thinking about a sustainable built environment then these wider environmental considerations must also be taken into account, as well as social issues of creating better places with good connectivity to local amenities and not creating isolated communities dependent on the car.

The concept of embodied impacts of construction products is not new to manufacturers

-              Prior to the publication of EN 15804 in 2013, life cycle assessment of construction products in the UK was carried out by the Building Research Establishment (BRE) as the basis of its Green Guide for Building elements.  This meant that UK manufacturers have worked with BRE from the mid-1990s on providing information to carry out a life cycle assessment, i.e. to produce information on the embodied impacts of construction products, including embodied carbon.  The first Green Guide was published in 1996The 2009 revision of the Green Guide included for each building element a column giving the embodied carbon figures.  The BRE LCA methodology was subsequently aligned with the emergence of the European wide EN 15804 standard for Environmental Product Declarations. 


-              Thus although for many in the construction sector, especially it seems amongst architects and designers, the concept of embodied carbon is a completely new one brought to prominence in the past two years, especially as a consequence of the climate demonstrations and Extinction Rebellion. For manufacturers embodied impacts and embodied carbon is not a new concept.  The CPA co-authored in 2012 A Guide to Understanding the Embodied Impacts of Construction Products, including embodied carbon.   Its opening paragraph says:


              The quest for a more sustainable and more recently a low carbon built environment has meant that the demand for information on the impact of construction products has increased dramatically.  Much attention is being given to the ways of designing and constructing buildings and whilst the focus has been on energy efficiency and capturing renewable energy, there is a growing awareness that the embodied impacts of construction products and especially embodied carbon will become increasingly important.


                            And that was written 9 years ago.


-              It is essential that the skill to carry out whole life carbon assessment becomes commonplace within the design community, and that they are taught the skill in university architectural and engineering courses.  Government itself must also take on the necessary technical expertise.


Materials and Products


-              Materials and products are not the same thing.  The Inquiry notification refers sometime to materials and sometimes to products.  Many construction products are made of a variety of different materials combined together.  Windows for instance have glass (which itself can have different properties), a frame that can be made of steel, aluminium, wood, plastic and the fittings and fixtures can be brass, nickel, wood, plastic, stainless steel.  Also likely to be part of the window are adhesives and sealants, perhaps nails and screws, to bind the materials together, and also coatings and paints either to act as preservative  or for decoration or both.  All of these materials can be combined in different ways.   The same is true for internal walls, external walls, roofs etc.  


-              Even those construction products which are primarily one material may have varnishes, preservatives, coatings on themThe idea of one material out of which all products will be made is very simplistic and the level of complexity involved in a building needs to be acknowledged in these debates and discussions. Windows will need a panel to see through, that material for many centuries has been glass.  It is energy intensive in the making, what can we do to lower the energy intensity of the see through material that our buildings require


-              The question of what is the product goes deeper.  Is it construction products or are they the components of a bigger product – the building structure itself – the home, the office etc.  It is surely he structure for which we want to find the lowest whole life carbon solution.


Origins of the materials used in a construction product

-              Any product used in the structure of a building is a construction product regardless of whether its origins are biological, geological or chemical and all products have an impact on the environment.

-              All construction products regardless of the material they are made from will need an LCA assessment.  Even nature based materials are grown, or farmed and are subject to inputs such as nutrients, herbicides, pesticides, medicines and antibiotics, harvesting, farming, potentially curing, processing, drying, and perhaps some form of manufacturing intervention.  The environmental impact of these inputs and the subsequent emissions to air, water and soil, including embodied carbon will need to be assessed through a life cycle assessment.  One of the earliest environmental catastrophes was from pesticides such as DDT leaching into water courses and accumulating through the food chain.  Similarly the run off from nitrogen and phosphates in agriculture resulted in eutrophication of water courses.  

-              Embodied carbon of a product comes from the energy used for extraction, manufacture, use and disposal of that product (the lifecycle), as well as in some instances the chemical process itself. As the grid decarbonises in coming years due to a switch from fossil fuel-based energy sources to low carbon sources then the embodied carbon of those products which are energy intensive in their manufacture will fallCurrently the embodied carbon of a product manufactured in France which has an energy base largely of nuclear is lower than the same product manufactured in Poland which is largely still dependent on coal fired energy.   Obviously for different products different stages of the lifecycle are important in regard to carbon emissions.

-              A comment about nature-based materials and the question of product availability and demand. If increased demand leads to a rise in production, then this may impact land use.  This has happened with for instance soy or oil palm where increased demand has caused natural forest to be replaced by plantations and subsequent loss of biodiversity.  Similarly, increasing demand for cashmere for the textile industry is causing an increase in flock size in Mongolia leading in some places to heavy degradation of pasture and desertification.  All things have to be managed to ensure no degradation of the environment.  A life cycle assessment is a tool to assess such a complex set of issues.


We would be happy to provide further input to the Committee.

May 2021