The purpose of this new guide, written by Jane Anderson from PE INTERNATIONAL & Jane Thornback from the UK's Construction Products Association, is to improve understanding across the construction industry of the embodied impacts of construction products.
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 new 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.
What the Guide explains
Within the construction product sector, the measurement of environmental impact is not a new activity. The guide explains how the environmental impacts of construction products are measured; what processes and schemes are already established; what information is generated; how this is used and assessed at the building level and what effect European Regulations and emerging European Standards will have.
Construction products
Construction products are made of a variety of materials, which are manufactured into a myriad of products that combined together create buildings or infrastructure that make up the very fabric of our society. A construction product is a component of a building and not the building itself.
The impact of a construction product must therefore always be considered in the context of the role it performs in a building. For example, insulation makes a building more energy efficient and that function may outweigh many times the environmental impact of its manufacture and disposal.
Life Cycle Assessment
All products, not just construction products, have an impact on the environment and this impact can occur at any time during the manufacture, usage or at end of life. All these stages are collectively called a life-cycle.
Construction products have impacts from extraction of raw materials, processing and manufacture, maintenance and refurbishment, to eventual end of life and disposal. The measurement of this impact is called Life Cycle Assessment (LCA). There are two types of LCA for construction products: generic assessments that collate data from several manufacturers of the same type of product to create an industry average; and proprietary assessments that use information from a specific manufacturer and the LCA is specific to their product. This guide outlines the procedures that must be undertaken to implement a life cycle assessment in accordance with international standards.
Environmental impacts
LCA measures environmental impact across a range of issues such as impact: on air quality; on water usage and water quality; on toxicity to human life and to ecosystem functioning; on impact on global warming; as well as resource use. In the 1970s the main concern in Europe was acid rain, today it is climate change. The importance of these issues can change over time as society’s concerns and priorities change. The guide provides a detailed description of the commonly assessed environmental indicators.
Environmental Product Declarations (EPD)
The construction industry has adopted a particular approach to communicating LCA data known as an Environmental Product Declaration or EPD. This has been developed to provide environmental information from LCA studies in a common format, based on common rules known as Product Category Rules (PCR). EPD have been used for construction products since the first environmental assessments schemes were developed in the 1990s and an ISO standard for EPD sets out the standards they should meet.
EPD can only be compared when the rules of the PCR used are the same and all the relevant life cycle stages have been included. Additionally, products cannot be compared unless their functionality and use are considered at the building level within a system. The guide provides examples of what EPD look like.
EPD Schemes across Europe
Many European countries have developed national LCA schemes producing EPD, these include France, Germany, the Netherlands, the Scandinavian countries and the UK. The best known scheme in the UK is that developed by the Building Research Establishment (BRE) which since the mid-1990s has gathered information from UK manufacturing industry and amassed it into an environmental profiles database.
This database is a major component of the BRE’s Green Guide to Building Specification which is used in the government’s Code for Sustainable Homes and in the BRE’s environmental rating system for buildings called BREEAM.
The European Single Market and construction products
With the advent of the European single market for construction products, the European Commission became concerned that national EPD schemes and building level assessment schemes would represent a barrier to trade across Europe. The EU therefore sought a mandate from the EU Member States to develop European standards for the assessment of the sustainability performance of construction works and of construction products. This mandate is called CEN/TC 350.
From 2010 European standards began to emerge from this process and Standard BS EN15804 was published in February 2012 providing core rules for construction product EPD.
European Regulations and Standards
The Construction Products Directive of 1989 was one of the first Directives from the EU Commission to create a common framework for the regulations on buildings and construction products. It has been replaced by the Construction Products Regulation and is legally binding throughout the EU.
The CPR includes requirements for the sustainable use of natural resources, the reduction of greenhouse gas emissions over the life cycle and the use of EPD for assessing and reporting the impacts of construction products. If an EU Member State wishes to regulate in these areas of sustainability it must use European standards where they exist when regulating and must withdraw national standards. This means that in the case of the CPR a Member State must use the CEN/TC 350 suite of standards.
Assessing the impact of materials and products at the building level
An EPD provides robust and consistent information that can be used in building level assessments and the guide elaborates on the variety of ways that this can be done. In addition a number of building level tools are emerging aimed at improving decisions at the design stage by combining embodied environmental impact data and whole life cost data (i.e. economic) and link them to BIM (Building Information Modelling) data.
The future
Across Europe, the various environmental rating schemes are seeking to harmonise the ways in which they assess products and buildings.
Increasingly models are emerging to link embodied impacts with operational data thus enabling a better understanding of the trade-off between operational and embodied impacts and in time benchmarks for different types of buildings will emerge. All of which contributes greatly to the goal of a low carbon, more resource efficient, sustainable built environment.
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