Under impulse of the Product Environmental Footprint (PEF) initiative, CEN/TC350 wants to extend the current set of LCIA impact categories in the EN 15804 (CEN 2013) for the LCA of construction products. This study investigates the practical implementation of those additional impact categories, their relevance on building level and how their inclusion influences the conclusions drawn from a building LCA. This is analysed based on a building case study. The results indicate that without any form of aggregation the additional indicators do not drastically change the conclusions drawn from a (comparative) building LCA; however they may influence the identification of the most impacting materials and processes. Moreover, the choice of the aggregation method may lead to different interpretations Finally, a variety of issues were identified concerning the robustness of the results, LCI data and/or characterisation factors related to the toxicity indicators, water resource depletion, and land use biodiversity.

This paper presents the Belgian approach to mainstream LCA in the construction sector. This approach includes three main initiatives. Firstly, an LCA method and expert model, called MMG, was developed to assess the environmental impact of building elements and buildings in a harmonized way. Secondly, a national database with specific data for Belgian construction materials based on Environmental Product Declarations (EPDs) was established. Thirdly, the MMG expert model was translated to a web-based calculation tool, called TOTEM, which is oriented towards designers and building stakeholders. An overview of these three main initiatives is given in this paper.

According to the EN 15804 and EN 15978, a material or building life cycle consists of three major life cycle stages or so-called modules: Production and Construction (module A), Use (module B) and End-of-life (module C). Potential benefits and loads occurring beyond the building’s life cycle as a result of recycling, reuse or energy recovery can be declared in an additional module D. As part of the upcoming amendment of the EN 15804 a formula was developed to facilitate the calculation of module D. This paper provides a critical discussion on the practical use of module D. First of all, the development of the formula revealed specific methodological issues, such as the unequal approach to closed and open loop recycling. Secondly, the consideration of module D in a Belgian building LCA case study provided insights in the different methodological choices, interpretations, and assumptions related to the calculation of module D. This concerns for example the calculation of net output flows of secondary materials, modelling of avoided primary production, definition of the point of functional equivalence, efficiency of incineration, etc. Aspects that are not clearly specified in the standard and therefore can be open to interpretation are illustrated with concrete examples from the building case study. Where possible, recommendations for a harmonized approach are made. In any way, the results from the case study analysis reveal that the methodological choices can have a significant effect on the results and that module D results should therefore be considered with care.

According to the European standard for the assessment of the environmental performance of buildings (EN 15978), potential benefits and loads beyond the building’s life cycle as a consequence of recycling, reuse or energy recovery of building materials can be declared in module D. However, in practice module D is rarely included in LCA studies as it requires an optional calculation step and information at the product level (from EPD’s according to EN 15804) is often missing. By means of a case study analysis, considering five building cases with varying types of loadbearing structures, the present study evaluates the relative importance of module D on building level and provides a better insight in the main materials contributing to module D. The results show that based on the current Belgian end-of-life scenario’s the contribution of module D can be significant at the building level (representing up to 50 % of the total life cycle impact). This contribution varies more according to the LCIA indicator considered than to the building variant. In terms of the materials, the metals represent the main contributors to module D.

The main objective of the BTP1000 project was to design (and build) an office building ((sic)coffice) that would comply to the PassivHauss principles, offer a very high comfort and integrate different sustainability features, but cost no more than a traditional building. In order to achieve those objectives, an integrated iterative design approach was followed. From the beginning of the project, all stakeholders and various building specialists contributed to the decision making process, and design alternatives were evaluated from various perspectives (e.g. energy performance, comfort, life cycle cost and impact, etc.). The present paper focuses on how life cycle analysis (LCA) and life cycle costing (LCC) were used to integrate environmental and economic dimensions in the design process of the building envelope and how the results influenced final design options. LCA and LCC studies first compared different types of facades. The best compromise between LCC and LCA results, practical implementation, and thermal comfort were then selected for implementation. Subsequently, parametric energetic simulation results (combining heating, cooling, lighting, and ventilation) were used as input for LCA and LCC studies in order to optimise the insulation level of the building fabric elements (outer walls, roof, ground floor, glazing). In conclusion, LCC and LCA were very useful in the integrated design process and results showed the importance of taking into account not only the energy use for heating and cooling, but also for lighting into the building fabric optimisation.