There are two standards dedicated to the evaluation of the environmental impacts of buildings: the EN 15978 (2011) and the EN 15804 (2012), for the building and material levels, respectively. For infrastructure projects, it is covered by EN 15643-5 (2017).
- Building level (EN 15978)
EN 15978 (2011) provides calculation rules for the assessment of the environmental performance of new and existing buildings based on a life cycle approach. It is intended to support the decision-making process and documentation of the assessment of the environmental performance of a building. For a complete overview of the methodology the reading of the standard is referred.
- Product level (EN 15804)
At the product level, EN 15804 standard defines the product category rules to develop Environmental Product Declarations (EPD) of construction products. EPDs are Type III environmental declarations, according to ISO 14025 (2006) and are often a good source of environmental data for a life cycle analysis. An EPD is a particular type of LCA, conducted using a defined set of Product Category Rules (PCR). Many PCR can be used for construction products (CPA, 2012) but only EPD following the same PCR can be compared.
- Infrastructure level (EN 15643-5:2017)
This standard written by CEN/TC 350 provides a framework for a sustainability assessment of civil engineering works using life cycle approach. Although the standard covers social, economic and environmental aspects, the application of eToolLCD is focused on environmental indicators.The framework largely follows the modular approach used at buildings and product levels. The main difference is the inclusion of operational module B8 – Users Utilization that accounts for the use of the asset. For example, impacts associated with traffic using a road. These impacts shall be separately assessed and reported in module B8.
EN 15804 describes the methodology for producing EPD at the product-level while EN 15978 describes the assessment of environmental performance at the building-level. There must, therefore, be consideration given to the building level when working at the product-level. This is because any scenario choices that are made during the assessment at the product-level have implications for when this information is taken forward for the assessment at the building-level.
This interdependence is demonstrated by the information in Table 3 below, which lists the life cycle stages described by 15804 and 15978 and shows whether the results for a stage are dictated at the product-level or at the building-level or, in the case of future use scenarios, by both. For example, it is the product that dictates the environmental impacts of A1 to A3 and the product’s end of life disposal, but it is the building that will influence the environmental consequences of stages A4 to C3.
Figure 2 below further illustrates the interdependence between various EN & ISO standards.
ISO 14044 (2006) specifies requirements and provides guidelines for life cycle assessment (LCA) including: definition of the goal and scope of the LCA, the life cycle inventory analysis (LCI) phase, the life cycle impact assessment (LCIA) phase, the life cycle interpretation phase, reporting and critical review of the LCA, limitations of the LCA, relationship between the LCA phases, and conditions for use of value choices and optional elements. ISO 14044:2006 covers life cycle assessment (LCA) studies and life cycle inventory (LCI) studies.
ISO 21930 (2017) provides the principles, specifications and requirements to develop an environmental product declaration (EPD) for construction products and services, construction elements and integrated technical systems used in any type of construction works. ISO 21930 complements ISO 14025 by providing specific requirements for the EPD of construction products and services. ISO 21930 establishes a core set of requirements to be considered as core product category rules (PCR) to develop an EPD for any construction product or service. The assessment of social and economic impacts at the product level is not covered by this document.
References for Images & Further Reading: European Standards Briefing Paper, EN 15978, ISO 14044,