British Standards for the sustainability of construction works are being developed by BSI committee B/558. This committee provides the UK input into European standards committee CEN/TC 350 and International Standards Organisation committee ISO/TC 59/SC17.
The standards will provide a method for delivering information on the sustainability of works including embodied carbon for new and existing buildings. They are generally applicable (horizontal) and allow for the assessment of integrated performance of works over the life cycle of a structure. This means from raw material supply of building products to the final disposal of building components.
“Sustainable construction” in standards has three aspects: environmental, economic and social. The three impacts, altogether, must be considered and measured in order to be able to assess the sustainability of the whole works and calculation methods being developed for each area.
The standardised methodologies are voluntary and designed to work with national regulations, client briefs and independent sustainability assessment schemes.
The programme of work is on-going and the CEN standards work with existing ISO standards and those in development.
European framework standards
The framework standards provide the general principles and requirements for the assessment of buildings over their entire life cycle that has been agreed across the EU member states.
The framework standards are as follows:
The framework standards are now published and the calculation methods are being developed.
Environmental assessment is one of the three pillars of sustainability assessment of buildings. Calculation methods are designed to assess the environmental performance of buildings and are currently addressed in BS EN 15978:2011 and BS EN 16309.
BS EN 15978:2011 Sustainability of construction works – Assessment of environmental performance of buildings – Calculation methods
This standard applies to new and existing buildings and refurbishment projects.
It specifies the calculation method, based on Life Cycle Assessment (LCA) and other quantified environmental information, to assess the environmental performance of a building, and gives the means for the reporting and communication of the outcome of the assessment.
The approach covers all stages of the building life cycle and is based on data obtained from Environmental Product Declarations (EPD), their "information modules" (EN 15804) and other information necessary and relevant for carrying out the assessment.
The assessment includes all building related construction products, processes and services, used over the life cycle of the building.
The interpretation and value judgments of the results of the assessment are not within the scope of this European Standard.
The standard provides an outline of the steps to be followed when carrying out an assessment including
- Defining the purpose of the assessment e.g.
o for decision making such as
- comparison of different design options,
- refurbishment versus new build, or
- the potential for environmental improvements
o for legal requirements
o for the documentation of performance
o supporting policy development
- How to specify the object of assessment – i.e. the whole building, part of it, part of its lifecycle including
o Reference study period
o System boundaries for relevant lifecycle stages
o The building model
- Scenarios for defining the building life cycle including
o Time related characteristics such as maintenance, replacement, cleaning
o Climate conditions
o Scenarios for the different lifecycle stages including end of life
- Ways to quantify the building and its lifecycle
o i.e. all materials and products
FprEN 16309 Sustainability of construction works - Assessment of social performance of cuildings - Methods
- How to use other information including Environmental Product Declarations (ie developed under EN 15804)
- Calculation methods to evaluate each module in the life cycle stages
- Reporting requirements for the assessment results
- Verification of results where needed
The purpose of this standard is to provide rules for the assessment of the social performance of new and existing buildings as a part of sustainability assessment of the building.
This European standard uses the following social performance categories:
- Health and Comfort;
- Impacts on the neighbourhood;
- Safety and Security.
prEN 16627 Sustainability of construction works - Assessment of economic performance of buildings - Calculation method
The purpose of this European Standard is to provide calculation rules for the assessment of the economic performance of new and existing buildings as one part of an assessment of the sustainability of the building.
Economic performance assessment includes
- Life cycle costs and other economic aspects
- Economic risk assessment
- Return on investment calculations
- Economic aspects within the area of the building site
Environmental Product Declarations
Environment Product Declarations (EPD) provide environmental information on the impact of a construction product over its entire life cycle.
The life cycle assessments (LCA) of products has been carried out since the 1970’s when the negative environmental impact of certain products was identified and began to be addressed.
ISO standards were developed in the 1990’s to enable manufacturers and others to assess the impact of their products on the environment using a standardised methodology.
The construction industry has now established its own type of Life Cycle Assessment, called Environmental Product Declarations (EPD) which provides environmental information in a common format using common rules called Product Category Rules (PCR).
An EPD communicates:
- verifiable, accurate, non-misleading environmental information
- information that is expressed in modules allowing for easy organisation and expression of data packages throughout the lifecycle of a product
- underlying data that is consistent, reproducible and comparable
An EPD thus provides an executive summary of a process whereby all of the significant environmental effects over a product’s lifetime are calculated.
There are a number of benefits that have been ascribed to EPD such as:
- provides a useful comparison within product groups
- enables a manufacturer to scrutinise his own processes and make improvements
- a useful marketing tool for manufacturers
- helps architects make informed decisions about the materials they specify
- allows clients to calculate their own emissions along their supply chain
- subject to third party verification therefore reliable
Certainly some large manufacturers have had EPDs developed for their own range of products and subsequently made claims about their comparative performance.
Trade associations have generated EPDs at a generic level e.g. the aluminium industry, to enable manufacturing groups within their membership to make declarations without the expense of generating individual EPDs.
The standards do not, at this time, set specific levels, classes or benchmarks for EPD results.
These can be prescribed in the following ways:
- via a client’s brief
- in national building regulations
- in national application standards
- in building assessment and certification schemes
National schemes are established in various countries that allow comparisons between products that are measured using common PCRs. In the UK BRE’s Environmental Profiles is one such scheme. In the Netherlands a scheme was standardised under national standard NEN 8006 and in France under NF P01-010.
The publication of the new European harmonised standards relating to EPD provide a common methodology which means that products across Europe will be able to be compared.
EN 15804:2012 + 2014 A1 Sustainability of construction works – Environmental product declarations – Core rules for the product category of construction products
This European standard provides core product category rules (PCR) for Type III environmental product declarations (EPD) for any construction product and construction service.
It provides a structure to ensure that all EPDs of construction products, construction services and construction processes are derived, verified and presented in a harmonised way.
EPD information is expressed in information modules, which allow easy organisation and expression of data packages throughout the life cycle of the product. The approach requires that the underlying data should be consistent, reproducible and comparable.
The standard measures the following aspects:
- Environmental impacts Global warming Ozone depletion
o Acidification for soil and water
o Photochemical ozone creation
o Depletion of abiotic resources
o Renewable energy
o Non-renewable energy
o Primary/secondary (materials, fuels)
o Fresh water
o Components for re-use, recycling, energy recovery and exported energy
- Transport to the construction site (fuel, etc.)
- Installation in the building (ancillary materials/resources)
- Information relating to the expected use stage
o Reference service life
o Energy use
o Water use
It provides the manufacturer with greater clarity on their own processes and the purchaser with a short cut to supply chain carbon data.
The list below outlines related standards for EPD:
- PD CEN/TR 15941:2010 Sustainability of construction works – Environmental product declarations – Methodology for selection and use of generic data
- BS EN 15942:2011 Sustainability of construction works – Environmental product declarations – Communication format business to business
- BS EN ISO 14025:2010 Environmental labels and declarations - Type III environmental declarations – Principles and procedures
- BS EN ISO 14044:2006 Environmental management – Life cycle assessment - Requirements and guidelines
The issue of sustainable development is broad and of global concern, and, as such, involves all communities and interested parties. The below international standard presents general principles of sustainability related to buildings and other construction works.
BS ISO:15392:2008 Sustainablity in building construction - General principles
This International Standard presents general principles of sustainability related to buildings and other construction works. These general principles form the basis for a suite of standards intended to address specific issues and aspects of sustainability relevant to building and civil engineering of construction works.