|Aspect||G-24 Choice of LCI/LCIA datasets for simplified LCA|
||Different LCI/LCIA data are needed to assess the environmental impacts of buildings. They make it possible to quantify the different impacts related to the building products and equipment, the construction site, the operational energy and water uses, and the deconstruction of the building. Depending on the study type (screening, simplified, complete), different LCI/LCIA data can be used in practice, depending on their availability not only at the European level but also in a national context (average, generic or specific LCI/LCIA data for the building materials, products and processes).How can this be addressed for simplified LCA?|
Related study objective
|☒ stand-alone LCA||☒ comparative assertion|
Related study phase
|goal and scope definition||inventory analysis (LCI)||impact assessment (LCIA)||interpretation||reporting|
|new buildings||existing buildings||construction products||screening LCA||simplified LCA||complete LCA|
|Provisions||The LCA practitioner or the user of dedicated building LCA tools should use adapted data for the description of the building components in simplified LCA.In contrast with screening LCA, the data should reflect more closely the building element, product or material. They can either represent a full building component (e.g. 1 m2 concrete block wall insulated with wood wool), a building product (e.g. 1 m2 of rockwool) or a building material (e.g. 1 m3of ready-mixed concrete), depending on the need of the practitioner and the stage of the building project. Provisions for the choice of data to use for simplified LCA for the construction site, the operational energy and water uses, and the deconstruction activities are described in the corresponding aspects.Generic LCA data for the building elements cited above should come from available European or national generic LCA databases. It is possible to use average data (e.g. average EPD) if generic LCA are missing, or are less appropriate to the context of the study.
Generic LCA data may represent (if possible and if relevant) the total consumption mix in Europe (if the study is used for European projects) or in every European country, or the production mix in Europe or in every European country, or the production mix of a neighbouring country, using appropriate rules to adapt the generic data to the new context.
||In practice, the LCA data for a simplified LCA should represent the building elements, products or materials more closely than the data used for a screening LCA. Three different practical recommendations can be given for the use of data on the building elements, the associated LCA data and the currently available generic LCA databases.
1) Practical guidance for the use of data describing the building elements
The data describing the building components can correspond to generic typical components using default values for the major included products (width, thickness etc.). It may be possible to parameterize the thickness of the key included products (e.g. insulation or structural products) for each study or use.
Other data include building products and materials LCA data. These ‘raw’ data usually serve when deriving data for building components or parts of the building. Consistency should be ensured between the different levels of data (part of the building, components, products and materials).
2) Practical guidance for the use of generic LCA data for a European or national context
Examples of generic data on building products representing the ‘consumption mix’ can be found e.g. for the reinforcing steel sold on the French market in [Gomès 2012]. However, generally speaking, generic national data representing the ‘consumption mix’ in the various European countries may be missing. In this case, the use of existing generic LCA data (from neighbouring European countries) or industry-based data (from the national context) can be used as proxy data, using appropriate adaptation or contextualization rules. More guidelines on this topic can be found e.g. in [Hodkova 2012].
3) Practical availability of generic databases in Europe that can be used by the practitioner
The building practitioner may use existing European or national databases to collect generic LCA data to describe the building elements, products and materials, depending on the needs. Examples of such databases can be found e.g. on the LCA resources directory of the European Commission – Joint Research Centre, section ‘Databases’. Generic databases (mainly at the global or European level) include, for example, the ELCD, ESUCO and ecoinvent databases.
Other generic databases developed in some European countries include, for example: the German Ökobau.dat, the Swiss Catalogue Construction/KBOB databases, the French DIOGEN generic LCA database for construction materials used in civil engineering applications, and the various generic databases that are included in LCA software for buildings.