10DBMC International Conférence On Durability of Building Materials and Components LYON [France] 17-20 April 2005
ISO 15686-6 – Procedure for Considering Environmental Impacts
Wolfram Trinius Center for Built Environment, University of Gävle 80176 Gävle Sweden Ingenieurbüro Trinius Dorotheenstr 21, 22301 Hamburg Germany [email protected]
TT5-201
ABSTRACT
Within the ISO series on Service Life Planning of Buildings and Constructed assets, ISO/TC59/SC14 has developed part 6, which focuses on the interrelationship between Environmental Life Cycle Assessment (LCA) and Service Life Planning (SLP). It has recently been published and establishes a procedure for the inclusion of environmental impacts into the framework of service life planning of buildings. This paper intends to inform about this standard, to describe the main content and to discuss some of the main achievements reached during the development of the document.
With the scope also including whole life costs (WLC or equally LCC 'life cycle costs') and environmental aspects, the concept of service life planning is more and more developing into an approach for integrated planning of buildings and constructed assets. In order to achieve this, it was necessary to illustrate the way the concepts of SLP, WLC and LCA can benefit from each other, and how they relate. Eventually it also showed reasonable to establish a framework in which these concepts are linked with each other. As a result, ISO 15686-6 on one hand describes a procedure for the parallel conduction of technical/functional, environmental and economic assessments. The procedure is intended to be applicable in project planning. At the same time, the standard illustrates how environmental declarations of building products together with the results of service life planning can be applied in order to perform a case-specific environmental assessment of design options. By this, the procedure takes an important departure from other established methods and tools for environmental assessment of buildings: Assessment references are not related to overarching targets and intentions of some tool developer, they originate from the performance requirements established in the clients brief. To benefit from the context of SLP, the assessment procedure follows a modular structure, where the various life cycle stages are not intended to be aggregated before the use stage scenarios have been adapted to relevant influential parameters from the planned in-use condition.
The result is an assessment result that shall enable the designer to find solutions that clearly address and satisfy the requirements expressed in the clients brief. On the other hand, due to the case-specific references, results obtained in this context do not contain substance for generic conclusions or assertions.
KEYWORDS Service Life, Life Performance, Performance Requirements, Life Cycle Assessment
10DBMC International Conférence on Durability of Building Materials and Components LYON [France] 17-20 April 2005
1 INTRODUCTION
Service Life Planning of buildings and constructed assets is subject of international standardization since 1993. The main purpose of standardization efforts in ISO/TC59/SC14 “Design Life” is to identify routines that support the design of buildings that meet identified performance requirements, throughout their design life. With this purpose, also the demand from the European Construction Products Directive [CEC], that buildings are to meet 6 essential requirements throughout their working life, is addressed. In parallel to the efforts of ISO/TC59/SC14, other standardization committees, like ISO/TC59/SC17 “Sustainability in building construction” and CEN BT/WG174 “horizontal standards for assessment of integrated environmental performance of buildings” as well as international research networks, like e.g. PeBBu, address topics that ISO 15686-6 focuses upon: the link between concepts for service life planning and environmental assessment, performed in parallel with cost assessments; all concerning the entire life cycle of a building and recognizing life performance of a building and performance requirements posed to the building and its parts.
The aim of ISO 15686-6 is a description of how to assess potential environmental impacts of alternative designs of a constructed asset. As it is part of the standard series of service life planning, it aims at application in the design stage, however recognizing that design not only takes place associated with new buildings, but that also e.g. refurbishments apply a design stage, see figure 1. The assessment of design options is a logical consequence of the aim, the assessment is not supposed to be a generic assessment of environmental impact of some product or service. Rather, it serves the purpose to enable a designer to identify a design solution that is beneficial in relation to identified project specific targets, and within the context of the current building and the requirements posed to it. Figure 1: ISO 15686-6 procedure integrated into project planning
Project Initiation * life cycle of the constructed asset, in which the project is initiated Project Realisation
Analysis of Initial Detailed Design & Constraints Clients Brief Design Design Construction and Process Process Documents Potentials
ISO 15686-1 Technical and other Require- Assessment assessments ments
Performance Economic Targets require- ISO 15686-5 Assessment ments
Regulation ISO 14040 Environmental ISO 14025 Assessment ISO 15686-6
* Project may be initiated at any point in the life cycle of the building In order to succeed developing this module of the service life planning context, it was first necessary to identify the link between concepts like environmental life cycle assessment, environmental declaration, reference service life and service life estimation. All together, these currently ongoing standardization efforts in the field of “sustainability in building construction” enable the development of integrated concepts for consideration of sustainability aspects of building construction [Trinius 2004].
TT5-201, ISO 15686-6 – Procedure for Considering Environmental Impacts, Wolfram Trinius
10DBMC International Conférence on Durability of Building Materials and Components LYON [France] 17-20 April 2005
Where the topic of sustainable construction on one hand provides the contextual frame and the philosophical reason for acting on the topic of service life, the methodologies developed to identify reference service lives and estimated service lives, also in terms of service life declarations, provide input to in especially environmental product declarations of building materials and components, and equally evident, to the assessment of environmental performance of buildings. Both items are addressed in ISO/TC59/SC17 and in CEN/BT WG 174. These working groups, as well as the European TG4 Report on Life Cycle Costing in Building Construction [TG4], already apply the concept outlined in ISO 15686-6, which in itself was based on discussions in the SETAC Europe Working Group on LCA in Building and Construction [Kotaji et al].
The current development of international standards follows to large extent a modular approach that shall allow the inclusion of use phase (and thereby service life) scenarios that can be adapted to better reflect the situation in which a material, component or system is to be applied. The ISO 15686 standards on Service Life Planning can be applied in order to generate information for such adaptable modules and scenarios, 15686-6 illustrates how to do this.
2 INTEGRATING ENVIRONMENTAL ASSESSMENT INTO SLP
In general, every product has some impact on the environment, occurring during any or all stages of the product’s life cycle and being local, regional or global in character, or a combination of these. Environmental impacts associated with buildings and building products can be significant and should therefore be addressed as early in the design stage as possible. This also, as the economic consequences of design changes are larger the further the planning process has advanced, and as decisions already taken reduce the degree of freedom for decisions that have a contextual connection.
In order to avoid sub-optimization, environmental assessments of design options should most beneficially be performed in parallel with technical and economic assessments, all relating to project specific requirements and constraints. The purpose of all assessments is to provide decision makers and stakeholders with information relevant to their decision. Such comprehensive and reliable information about product performance is a rather complex item. The life cycle of buildings and their components are relatively long and the context of product application must be integrated in the information basis, where this context has an influence on life performance aspects of a design option. In this context, the environmental assessment draws significant benefits from the interlinkage with service life planning, as SLP aims to identify reasonable scenarios for predicted performance, and to make such scenarios more accurate.
A general recommendation to address environmental and sustainability aspects in project planning is to early involve relevant stakeholders in the design process. The concept established in ISO 15686-6 provides for such involvement. An assessment is to be performed making reference to established performance requirements. It is then up to the actor committing the SLP or the environmental assessment study, to ensure that performance requirements address a relevant scope of concern. As this scope of concern may vary between projects, results obtained based on the approach of 15686-6 are project specific and not generic.
Determining and assessing environmental impacts of design options, and to decide whether differences between options are significant enough to be a reliable basis for decision making, requires detailed information about the design options and the context of their application. This also results in the fact that the later in the design process an assessment is performed, the more accurate the scenarios applied in the assessment can be. This conflicts with the statement above, that the earlier the design addresses environmental concerns, the easier it is to adapt. Therefore, the design process often follows an interactive route.
TT5-201, ISO 15686-6 – Procedure for Considering Environmental Impacts, Wolfram Trinius
10DBMC International Conférence on Durability of Building Materials and Components LYON [France] 17-20 April 2005
For early life cycle stages of products and components, LCA data can often be obtained by performing an inventory of the production processes involved in the supply chain. When striving to address the full life cycle perspective, assumptions on the life cycle stages from construction to the end of life often have to be made, see figure 2. The current trend of environmental declarations to include a full life cycle perspective means, that the declaration contains a scenario for the use phase of the product. Adoption of an EPD in that case also means to integrate such scenarios, whether they correctly reflect the situation in the planned building or not. To solve this potential problem, ISO 15686-6 as well as the SETAC WG Building and Construction, strongly recommend that information be kept separate. This modularity in information then allows to analyze the incorporated scenarios, and to adapt them where necessary [Trinius 2005]. Figure 2 – ISO 15686-6 life cycle stages, data sources and the link to service life planning
3 ENVIRONMENTAL ASSESSMENT OF DESIGN OPTIONS AS ELEMENT OF PROJECT
Life cycle stages Data Sources Service Life Planning Process
cradle Extraction Acquired LCA Quantity of data Materials and Energy Material gate production
site Scenarios: e.g. Transportation, Construction Construction site, Service life, Predicted LCA Maintenance plan, End of life Use & data maintenance Quantity of Materials and Energy in Construction phase, Use phase including maintenance and replacements, End of life End of life grave
Estimated life time Material and Energy demand
Environmental impacts
Comparative assessment of Design options in Building context
PLANNING
Environmental assessment of construction products, elements or entire buildings may be carried out prior to, within, or after project planning. The purposes of these assessments will be different, as in especially assessments carried out:
• Prior to the design and planning process may provide information about materials and components that the designer can make use of in his work, or that may inform the client about key items of environmental performance. A classical example would be an environmental declaration that includes an assessment of the declared environmental information.
• Within the design and planning process, where the designer performs assessments of various options of the design work, in order to identify the overall most beneficial option. In such assessments, the options are assessed considering the context of the planned building at the currently available level of detail. In comparative assessments, the design options must, as part of a functional component, relate to the same requirements.
• After completed planning, or even after realization of building construction, in order to verify the result of the planning process or in order to assess the produced building.
TT5-201, ISO 15686-6 – Procedure for Considering Environmental Impacts, Wolfram Trinius
10DBMC International Conférence on Durability of Building Materials and Components LYON [France] 17-20 April 2005
As ISO 15686-6 is developed as a module of service life planning, it addresses the second of these assessment situations. For the assessment procedure, this means that
• Assessment references can relate to project specific requirements and targets and can address performance requirements derived from various stakeholders' fields of interest.
• Potentials and constraints related to the current project can be considered in the assessment
• With the development from initial design to more detailed design, the information about the building and its life cycle can be refined, leading to the possibility to involve more detailed information in the assessment, both relating to product performance and in-use conditions.
• When carried out based on information available from other items of service life planning, that information can be incorporated in scenarios underlying the assessment.
• Technical, economic and environmental assessment can be performed in parallel; all based on the same project specific considerations, enabling the designer to apply a broader basis for his decision taking.
3.1 Comparative assessment results obtained on 15686-6 basis have no generic validity
When making comparative assessments based on LCA methodology, numerous requirements apply, all with the intentions to enable “just” comparisons, see the ISO 14040 series on LCA [ISO 14040].
Comparisons must be made on the basis of a common functional unit. For comparative assessments of design options, the context is a still evolving (and hence not entirely determined) design, which means that the exact context of the application of the design options is not yet known, and that often a proper functional unit may not be possible to be determined. Further, in case of LCA in the design stage, it appears most important that the design options meet the same performance requirements rather than having the exact same functional unit. This leads then directly to a limitation of the validity of assessment results. Results obtained according to the procedure laid out in 15686-6 are only valid for the design situation for which they have been obtained. They are only assumed to support decision- making in that very design process and have no general validity. They should not be applied “as true” for other design situations.
Figure 3 aims to clarify that the design options 1 and 2 are not necessarily to be equal in functionality, but that they, together with their context, have to relate to the same requirements.
TT5-201, ISO 15686-6 – Procedure for Considering Environmental Impacts, Wolfram Trinius
10DBMC International Conférence on Durability of Building Materials and Components LYON [France] 17-20 April 2005
Figure 2 – ISO 15686-6 comparative assessment of design options
4 DISCUSSION AND CONCLUSION
The current trend appears clearly to be that the move from consideration of environmental aspects towards more holistic approaches. Often then, the term "sustainability" is involved. Broader approaches require an integration of numerous - formerly separated - approaches, which can be illustrated by the content and structure of ISO/TC59/SC17 and its proposed standards [ISO AWI 21930][ISO AWI 21931]. Benefits of integrating modules either relate to the importance in decision- making processes (like LCC and LCA), or appear as the modules provide each other with valuable information and strengthen each other's significance (like SLP and LCA/LCC). Where environmental declarations of construction products are equipped with scenarios covering the use phase and the service life, the link between SLP and LCA becomes evident. Meanwhile, the inclusion of life performance aspects in environmental declarations also means that aspects that are not related to the declared product alone, but refer to the application context of that product, are included in the declared information. A highly interesting field of assignment of performance and requirements is evolving, where product performance and building performance strongly rely on each other [Trinius, Sjöström]. Combined with the approach of performance-based building, SLP can address "life performance" in relation to project specific requirements. Both, these requirements, and the derived life performance can strengthen scenarios applied in LCA and LCC. Resulting is a concept for building assessment that is very much adaptable to project specific preconditions and performance aspects, as laid out in ISO 15686-6. Recently, focus has been directed onto standards for functionality requirements and serviceability [ISO AWI 21933-1]. "Sustainable Building" can very much benefit from this current development. And this development is not just academic or distant, international research networks, as well as standardization committees are actively and currently developing the modules needed for integrated and more holistic, yet more flexible assessments.
TT5-201, ISO 15686-6 – Procedure for Considering Environmental Impacts, Wolfram Trinius
10DBMC International Conférence on Durability of Building Materials and Components LYON [France] 17-20 April 2005
6 REFERENCES
CEC, ‘Council directive of 21 December 1988 on the approximation of laws, regulations and administrative provisions of the Member States relating to construction products’, Council of the European Communities, 1988, Brussels. 89/106/EEC TG4, 'European Commission TG4 report on: Life Cycle Costs in Construction', final report of the tripartite meeting group on the competitiveness of the construction industry, Brussels 2003 ISO 14040, ‘Environmental Management – Life cycle assessment – Principles and framework’, ISO 14040, International Standardization Organization, Geneva ISO/TR 14025, ‘Environmental Labels and Declarations – Type III environmental declarations’, ISO/TR 14025, International Standardization Organization, Geneva 2000 ISO 15686-1, ‘Buildings and Constructed Assets – Service Life Planning – General Principles’, ISO 15686-1, International Standardization Organization, Geneva 2000 ISO 15686-2, ‘Buildings and Constructed Assets – Service Life Planning – Service Life Prediction Procedures’, ISO 15686-2, International Standardization Organization, Geneva 2001 ISO 15686-6, ‘Buildings and Constructed Assets – Service Life Planning – Procedure for Considering Environmental Impacts’, ISO 15686-6, International Standardization Organization, Geneva 2004 ISO AWI 15686-9, ‘Buildings and Constructed Assets – Service Life Planning – Guide on the Inclusion of Requirements of Service Life Assessment and Service Life Declarations in Product Standards’, Standard developed by ISO/TC59/SC14, International Standardization Organization, Geneva 2004 ISO AWI 21930,‘Building Construction – Sustainability in Building Construction – Environmental Declaration of Building Products’, Draft International Standard developed by ISO/TC59/SC17, International Standardization Organization, Geneva 2004 ISO AWI 21931, ‘Building Construction – Sustainability in Building Construction – Assessment of Environmental Building Performance’, Draft International Standard developed by ISO/TC59/SC17, International Standardization Organization, Geneva 2004 ISO AWI 21933-1, ‘Buildings and Constructed Assets – Service Life Planning – Functionality Requirements and Serviceability’, ISO AWI 21933-1, International Standardization Organization, Geneva 2004 Kotaji, S., Schuurmans, A., Edwards, S., (Eds.) Life-Cycle Assessment in Building and Construction, Society of Environmental Toxicology and Chemistry 2003 Trinius, W., Sjöström, C., ‘Service Life Planning and Performance Requirements’, Building Research & Information, in print, London 2004 Trinius, W., ‘Sustainable building – Integrated planning concept and realisation in project planning’ European Roundtable on Sustainable Consumption and Production, Bilbao 2004 Trinius, W., ‘Modules of Environmental Performance Assessment related to Durability and Service Life’ 10DBMC International Conference On Durability of Building Materials and Components Lyon 2005
7 PROJECT REFERENCES CEN BT/WG174, European Standardization Working Group, developing standards for "integrated environmental performance of buildings" PeBBu, Thematic research network, for information see http://www.cibworld.nl ISO/TC59/SC14, ISO subcommittee on Design Life preparing ISO 15686 standard series on Service Life Planning ISO/TC59/SC17 ISO subcommittee on Sustainable Construction: Four standard documents are under preparation: (1) General Principles and Terminology; (2) Sustainability Indicators; (3) Environmental Declaration of Building Products; (4) Assessment of Environmental Performance.
TT5-201, ISO 15686-6 – Procedure for Considering Environmental Impacts, Wolfram Trinius