Annex 72 Subtasks

The Annex comprised the following five main subtasks (to operate partly in sequence as outlined in Section 6):

Subtask 1: Harmonised methodology guidelines

Subtask 2: Building assessment workflows and tools

Subtask 3: Case studies

Subtask 4: Building sector LCA databases

Subtask 5: Dissemination

Subtask 1: Methodology guidelines

Subtask Leader: Thomas Lützkendorf, Centre for Real Estate, Karlsruhe Institute of Technology (KIT), Germany

This subtask will focus on further developing and extending the methodology guidelines on life cycle assessment of buildings and on benchmarks. It will start from the guidelines and approaches agreed within IEA EBC Annex 57. The guidelines will be extended to the full life cycle of buildings and include operational impacts. Regional and national traditions will be captured to the extent feasible and necessary. A clear distinction is made between modelling practices on one hand and data and databases on the other. The subtask will be divided in the following activities:

Activity 1.1. International survey on the methodologies applied to assess the environmental impacts of buildings with regard to modelling aspects, system boundaries and environmental indicators, including an analysis of their degree of dissemination and frequency of use among designers, as well as the demand for assessment results.

Activity 1.2. Definition of at least two reference buildings (size, materialisation, operational energy demand, etc.) on which the (existing national) assessment methods are applied using national (if available) databases and (national/regional) approaches. The results of these assessments are compared in view of identifying major discrepancies. The results of this activity are used to better target harmonisation efforts and identify areas of disagreement with little or no potential for harmonisation.

Activity 1.3. Report on harmonised methodology to assess the primary energy demand, greenhouse gas emissions and environmental impacts of buildings. This report covers modelling aspects such as allocation and recycling, onsite electricity production, reference service life / reference study period, uncertainty or electricity mix as well as recommendations on environmental indicators. This report also highlights the areas of disagreement by offering two (or, in exceptional cases several) alternative approaches.

Activity 1.4. Report on the methodology(ies) on how to develop benchmarks for primary energy demand, greenhouse gas emissions and environmental impacts of buildings. If considered feasible, this report will also include proposed region- or nation-specific benchmark values for different types of buildings.

Subtask 2: Building assessment workflows and tools

Subtask Leader: Alexander Passer, Institute of Technology and Testing of Construction Materials, Working Group Sustainability Assessment, Graz University of Technology, Austria

This subtask will focus on the description, the analysis and outlook of national or regional state-of-the-art building assessment tools, the integration of environmental information in planning tools and requirements in different planning stages with focus on LCA and BIM. The subtask will be divided in the following activities:

Activity 2.1. Surveys among LCA experts and design decision makers on national practices of workflows and planning tools, methods, data formats etc. Report on the current state and potentials of implementing the assessment of life cycle related environmental impacts of buildings during the design process.

Activity 2.2. Identification of requirements for the implementation of life cycle related aspects in different stages of the design and planning process. Proposal for implementation strategies in view of internationally compatible solutions of planning tools and formats (e.g. BIM) to integrate life cycle information (e.g. following existing structures of a cost calculation approach).

Activity 2.3. Analysis on how differences in building models (completeness and detailing) can be taken into account throughout the planning process (e.g. application of correction factors). Establish guidelines for measuring the completeness of a building model to indicate how it can be used for life cycle assessment of buildings.

Activity 2.4. Guidelines for design decision makers on how to use available information to assess the life cycle-related environmental performance of buildings during the design process for their improvement.

Subtask 3: Case studies

Subtask Leader: Harpa Birgitsdottir, Danish Building Research Institute, Aalborg University Copenhagen, Denmark

A substantial set of building case studies will be analysed for which the life cycle based environmental impacts are quantified using either national/regional assessment practice or the methodology agreed in Subtask 1. These case studies are helpful in establishing empirical benchmarks based on the methodology developed in Subtask 1.

Such benchmarks related to the primary energy demand, greenhouse gas emissions and environmental impacts of buildings will be regionally differentiated and tied to different building types such as residential, office, or school buildings. It is explored whether or not a typology of climatic regions can be established to allow empirically derived benchmarks being applied across the participating nations.

Other potential areas of analytical focus will be investigated in the early phases of the subtask activities. A preliminary call for case studies has been used to reveal the possibilities of attaining case studies focused around the topics of activity 3.3 and 3.4.

The subtask will be divided into the following research activities:

Activity 3.1. Quantify the primary energy demand, greenhouse gas emission and environmental impacts of a set of country-specific building case studies using the harmonised methodology developed in subtask 1 and 2. The buildings selected should be representative to the country/region. The set of case studies should include different building types and different decision-making situations. Harmonised documentation of these case studies, including the information on the use (covering e.g. use profiles) of the buildings analysed as well as the climatic zone.

Activity 3.2. Derive national or regional benchmarks for different building types (residential, office, school buildings, and possibly others) using the results of Activity 3.1. Different reference units (functional equivalence) will be analysed in order to develop benchmarks (impacts per m2 and year basis, impacts per person etc.). The feasibility and possibility of defining internationally applicable benchmarks for similar climatic zones will be explored. The benchmarks shall apply on the entire life cycle of buildings and be subdivided into embodied environmental impacts (production of materials and technical systems, construction, use and end of life) and operational impacts during the use phase.

Activity 3.3. Classify and characterize different approaches to optimizing life cycle energy and carbon performance of new buildings and renovation projects based on the case studies from activity 3.1. Assess the environmental potential of different types of optimization strategies and present results as guidelines for building design and decision-making.

Activity 3.4. Analyse case studies focusing on the decisions in the planning and design workflow which have an impact on the whole life energy/carbon of the building. Many decisions will be taken with no thought of energy or carbon – for instance the choice of structural frame may be based on architectural layout and on construction industry norms for that country, while facade material may depend on local planning requirements, etc. The aim is to give examples and in-depth knowledge on process aspects promoting or hindering a relevant application of life cycle aspects in building design.

Subtask 4: Building sector LCA databases

Subtask Leader: Rolf Frischknecht, treeze Ltd., Switzerland

This subtask will focus on the development and supply of life cycle assessment databases targeted to the building sector. It mainly addresses countries with a current lack of reliable, country specific LCA database. The subtask will be divided in the following activities:

Activity 4.1. Survey and report on national/regional life cycle assessment databases either in general use or particularly used in the construction sector (representing construction products, building equipment, eventually building elements). The survey will explore on the national needs (data gaps) and provide recommendations in view of further improving the situation regarding data. Driving forces for the demand on LCA data and databases (requirements from regulation, subsidies, labelling systems) will be analysed. The report includes an appendix with a standardised description (using a template) of the database contents.

Activity 4.2. Develop guidelines and practical hints on how to establish a publicly available LCA database suited for the building sector. Such a document will include considerations related to the need of national databases, information related to the contents of such databases as well as organisational aspects (e.g., on how to organise data collection and funding, how to organise updates, etc.).

Activity 4.3. Implementation of the guidelines (developed in Activity 4.2) in country case studies compiling a default set of publicly available national environmental indicator results of construction materials, building technology, energy supply, transport services and waste management, which is suited to be used in the preliminary design stage or in case of lack of more specific information.

Subtask 5: Dissemination

Subtask Leader: Rolf Frischknecht, treeze Ltd., Switzerland

This subtask is supporting the Subtasks 1 to 4 in communication and dissemination of the results achieved. The subtask will be divided in the following activities:

Activity 5.1. An Annex specific website will be established and operated with an internal area for exchange and co-ordination during the project.

Activity 5.2. The results of the different Activities of Subtasks 1 to 4 are documented in final reports and electronic files (where appropriate). These reports adhere to the publication requirements (contents and layout) of IEA EBC.

Activity 5.3. Two public international events will be organised as special sessions within international conferences such as the Sustainable Built Environment (SBE) series. A first international workshop is scheduled for after the methodology guidelines are agreed within the Annex experts. The event is targeted to stakeholders (professional investors, public and private building owners, construction material manufacturers). The feedback received from the attendees is used to further improve and to finalise the methodology guidelines. The second event is organised at the end of this Annex to present the findings and disseminate the results.

Activity 5.4. Organisation of national/regional workshops to inform and discuss the results with national/regional policy makers.

Activity 5.5. A series of scientific papers and/or a book will be published from the results obtained in the different Subtasks besides the final reports published within Activity 5.2.

Annex Info & Contact

Status: Completed (2016 - 2023)

Operating Agent

Rolf Frischknecht
treeze Ltd.
Kanzleistrasse 4
CH - 8610 Uster