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Tag: Related study phase: Inventory analysis (LCI)

G-25 Choice of LCI/LCIA-datasets for complete LCA

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Aspect G-25 Choice of LCI/LCIA-datasets for complete LCA
Description
 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 or complete), different LCI/LCIA data can be used in practice, depending on their availabilities at the European level, but also in a national context (average, generic or specific LCI/LCIA data for building materials, products and processes). How can this be addressed for complete LCA?

Related study objective

 ☒ stand-alone LCA ☒ comparative assertion

Related study phase

 ☐ ☒ ☐ ☐ ☐
goal and scope definition inventory analysis (LCI) impact assessment (LCIA) interpretation reporting

Relevant for
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 description of the building components in complete LCA. In contrast with simplified LCA, the data should reflect the building element, product or material more closely. They can represent a full building component (e.g. 1 m2 concrete block wall insulated with wood wool), or a building product (e.g. 1 m2 of rockwool) or a building material (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 complete LCA for the construction site, the operational energy and water uses, and the deconstruction activities are described in the corresponding aspects.LCA data for the building products cited above should correspond to specific industry data (e.g. EPD data) provided by the building manufacturers at the European level, or also in the national context; generic or average LCA data (refer to the provisions for simplified LCA) should be used if specific data (e.g. EPD) are currently missing for some building products or technical equipment.Cut-off rules and impact categories may be considered according to the ILCD Handbook if the goal of the study is to assess indicators and data beyond the EN 15804 cut-off and impact category. The practitioner is likely deviate from the above provision and use instead generic or average datasets providing a high level of detail in terms of the cut-off and impact categories to be calculated.
Rules from:

EN 15978

 9.4 Type of data for the assessment
The type of LCA data for the assessment referred in EN 15978 to the CEN/TR 15941. The choice of the data will depend on several aspects including stage of the building project, intended use/scope etc. According to EN 15978 the data (either bill of quantities, building description of components or the LCA data) may be given in different types: aggregated, specific, generic, average. They describe different levels of specificity concerning the description of the building components as well as the representativeness of the LCA data.

ILCD

 7.5 Developing generic LCI data
7.6. Selecting secondary LCI datasets
7.7 Averaging LCI data
According to the ILCD Handbook, a dataset is a generic dataset if “it has been developed using at least partly other information then those measured for the specific process. This other information can be stoichiometric or other calculation models, patents and other plans for processes or products, expert judgements etc. Generic process can aim at representing a specific process or system or an average situation.”

According to ILCD, the supply mix for an average data is the production mix plus the import mix i.e. the mix of what is available in the country for consumption. This applies to a specific data like an EPD for a product sold by a company.

Figure 14 representing the trade relations between countries, as a basis for calculating the production, consumption and supply mixes of products [ILCD 2011a]
Guidance
 In practice, the LCA data for a complete LCA should closely represent the building components, products or materials, or the part of the building. The building LCA practitioner may use an existing national EPD database to collect specific EPD data on building products, depending on the requirements. Three different practical recommendations can be given for the use of data on building elements, the associated LCA data, and the currently available specific (e.g. EPD) databases.1) Practical guidance for the use of data describing the building elements

The data describing the building components should correspond to the components implemented in the building. Please refer to the description of the complete LCA study type for more information.

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 for complete LCA (part of the building, components, products and materials).

2) Practical guidance for the use of specific LCA data for a European or national context

ILCD provisions can be consulted concerning the consumption mix of the building product. Specific data such as EPD reflects the production volume of a building product sold on a national market.

3) Practical availability of specific (e.g. EPD) databases in Europe that can be used by the practitioner

Specific EPDs may be found in available national EPD databases or European EPD databases (e.g. ECO-EPD). Examples of such databases can be found several European countries:

France: INIES

Germany: Institut Bauen und Umwelt

UK: BRE Profiles

Spain: DAPc system

The Netherlands: MRPI

Finland: RTS

The International EPD (R) ‘The Green Yardstick’ also provides EPD data for some European countries, such as Sweden and Italy.

If specific EPD are not available, the practitioner may use generic data or average industry data. Consultation of the LCA Resources directory of the European Commission – Joint Research Centre, section ‘Databases’ may be then needed. Generic databases include, for example, the ELCD, GaBi and ecoinvent databases. Other generic databases developed in European countries include, for example, the German Ökobau.dat and the Swiss Catalogue Construction/KBOB databases.

Care has to be taken when using EPDs for complete LCA, as they may not include a full LCI (depending on the PCR, only environmental indicators may be required). Thus they may not allow the use of LCIA indicators outside the scope of the Product Category Rules. For example, the EN 15978 standard does not yet include land use, toxicity or ecotoxicity indicators. The same remarks apply to cut-off rules and infrastructures issue.

The LCA practitioner should be aware here that the choice of LCI/LCIA datasets for complete LCA is intended primarily to be as accurate as possible for the current impact of the manufacture of a building product. However, the cut-off rules and LCI documentation may not be as comprehensive as needed by the practitioner.

For alternative goal definition beyond the scope of EN 15804, the practitioner may need a complete LCI in order to consider a full suite of impact categories. The same applies for the cut-off criteria. In this special case, the practitioner is likely to rely on generic datasets that may be the only possible way to provide such a level of detail (LCI, cut-off rules).

At this point, there is a trade-off between using specific data for a commercial reference of a product, and maintaining a high level of detail in terms of LCI, cut-off rules etc.

G-26 Use of building physical description data

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Aspect  G-26 Use of building physical description data
Description
 The type, the format, the level of detail and the quality of building-related data depend on the time of assessment (e.g. concept stage, basic design stage, detailed design stage, as built), on the objective of the study, and on the building’s stakeholders. Which kind of data should be used for a building LCA study?

Related study objective

 ☒ stand-alone LCA ☒ comparative assertion

Related study phase

 ☐ ☒ ☐ ☐ ☐
goal and scope definition inventory analysis (LCI) impact assessment (LCIA) interpretation reporting

Relevant for
new buildings existing buildings building products screening LCA simplified LCA complete LCA
Provisions The data for describing the main building elements should be taken from the building’s project documentation already available at the time of the assessment; otherwise use specific documentation included in the LCA software for buildings (if relevant). Different building-related data may be used in the documentation, depending on the objective of the study and the time of the assessment. For example, for screening LCA, an average description of a building could be sufficient, whereas for complete LCA a specific and detailed description of the building should be used wherever possible. Once the building-related data are quantified, they should be associated with suitable LCA or EPD data (see aspect ‘LCA datasets’).
Rules from:
 EN 15978

7.5.2 Description of the physical characteristics of the building
9.4 Type of data for the assessmentThe choice of the data in EN 15978 will depend on several aspects, including the stage of the building project, and the intended use or scope. According to EN 15978 the data (either the bill of quantities, a building description of components, or the LCA data) may be given in different types: aggregated, specific, generic or average. They describe different levels of specificity concerning the description of the building components as well as the representativeness of the LCA data.
Guidance
 The description of the quantities of the building products may vary significantly in terms of precision between the early design of a building project and the very late stages the project.Practitioners should always ensure that the building description is consistent between the various documents used, as the documents are all not produced at the same, time and building projects change over time. For example, it is essential to check whether the energy consumption results are based on assumptions regarding the mass of the building products, rather than the quantity take-off available in separate documentation.Generally, in early design, the level of description is low, as the design team does not know yet exactly what the specific description of the elements will be. For instance, the reinforced concrete in early design stages is described mainly in ml or m3, with a ratio for the reinforcing steel included in the concrete.However, during the detailed design, the level of description of the building elements is increased. At this stage, the building-related data may be more precise for some building elements (e.g. for the façades), whereas for others (e.g. the floor coverings), it may be only roughly taken into account until the actual building occupants are found.Common units that can be found in the building’s project documentation are: ml, m2, m3, unit etc. The practitioner should be aware of the potential differences in terms of the functional or declared units of LCA data available in LCA software for buildings and some of the units of the building-related-data (the quantity take-off). Wherever possible, the practitioner should use the most appropriate LCA data that correctly match the building-related data for the corresponding stage of the project.

B-01 Emissions of dangerous substances to indoor air during the use stage

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Aspect B-01 Emissions of dangerous substances to indoor air during the use stage
Description
 This aspect concerns the emissions of regulated dangerous substances from building products into indoor air, which can have an impact on health.

related study objective

 ☒ stand-alone LCA ☒ comparative assertion

related study phase

 ☒ ☒ ☐ ☐ ☐
goal and scope definition inventory analysis (LCI) impact assessment (LCIA) interpretation reporting

relevant for
new buildings existing buildings construction products screening LCA simplified LCA complete LCA
Provisions The emissions of health-related substances into indoor air during the use stage should be assessed in the context of a complete LCA, according to the European standards from CEN/TC 351: see guidance below.
Rules from:
 EN 15978:

7.4.4.2 Boundary of the installed products in use (Module B1)

EN 15804:

7.4 Additional information on release of dangerous substances to indoor air, soil and water during the use stage

7.4.1 Indoor air

ILCD:

“ISO 14044 names ‘emissions to air, water and soil’ as top-level classification, while recommending further differentiation as required for the given goal and scope of the LCA work.” ILCD Handbook: Framework and requirements for LCIA models and indicators: “This guidance document provides a framework and requirements for the models that are used to analyse the emissions into air, water and soil,…”
Guidance

The boundary of Module B1 includes impacts such as the release of substances from the façade, roof, floor coverings, internal finishes and other products that affect indoor air quality, which should be assessed according to the CEN/TC 351 standards, once these are available. The use stage starts at the point of practical completion of the construction work and runs to the time when the building is deconstructed or demolished.

EN 15804 is clear that the effects of health-related emissions and indoor air quality are not part of LCIA, but are considered and reported separately.  An emission, for example of a volatile solvent, from a product manufacturing process, installation process or product during use can be assessed as part of LCIA (e.g. POCP impact), irrespective of where and when the emission happens; the impact will be reported in the life cycle stage in which the impact occurs. But the effect of the emission from the product during use into indoor air where occupants are living or working can have separate health-related impacts that will be dependent on time and location, and are different from the impacts measured in LCIA. TC 351 provides guidance on how to report information on the health-related emissions from products in use, and covers emissions to air, water and soil (the emissions to water and soil are covered separately by Aspect B-02).

The guidance provides information on how to collect consistent data on indoor air emissions, and how they can be used in impact assessment methodologies.

The emissions of dangerous substances into indoor air during the use stage should be assessed according to the CEN/TC 351 standards.

The robustness programme is in progress in 2012, and the validated standards will be available in 2013. A list of regulated dangerous substances possibly associated with building products under the CPD (Construction Product Directive) Regulation has been established at European level [EC 2011]. This list indicates the substances and parameters that the evaluation should focus on. No aggregation is foreseen. For each pollutant, limit values can be defined at national level. At present, regulations exist in some European countries, such as Germany [AgBB 2010] and France [JORF 2011], and many voluntary labels exist at the European level [EC 2005a]. The results from CEN/TC351 tests will be integrated into the CE marking scheme, and allow products to meet CPR basic requirement No. 3 on Hygiene, Health and Environment [EC 2005b]. They are complementary to the results obtained using the LCA methodology.

Further work is necessary in order to establish scientific and pragmatic links between the data obtained by an LCA approach (CEN/TC 350 work) and that obtained by using emissions protocols (CEN/TC 351 work).

Some information on this issue is given in the LoRe-LCA project [LoRe-LCA 2011]. For more information on the link between LCI data on air emissions and LCIA method please consult the ‘Human toxicity and ecotoxicity indicators’ aspect.

For comparative assertions, simulation data are comparable if based on the same scenarios and hypothesis. All the parameters and hypotheses should be mentioned and explained together with the results in order to improve comparability.

 

B-02 Release of dangerous substances to soil and water during the use stage

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Aspect B-02 Release of dangerous substances to soil and water during the use stage
Description
 The release of dangerous substances to soil and water during the use stage concern the on-site water pollution induced by leaching (water contact with the built environment). These are expressed in mg of the released substance per m2 or kg of the exposed product, per time unit (e.g. year) and service life.

related study objective

 ☒ stand-alone LCA ☒ comparative assertion

related study phase

 ☒ ☒ ☐ ☐ ☐
goal and scope definition inventory analysis (LCI) impact assessment (LCIA) interpretation reporting

relevant for
new buildings existing buildings construction products screening LCA simplified LCA complete LCA
Provisions The release of dangerous substances to soil and water during use stage should be assessed in the context of a complete LCA, according to the European standards from CEN/TC 351.
Rules from:
 EN 15978:
7.4.4.2 Boundary of the installed products in use (Module B1)EN 15804:
7.4 Additional information on release of dangerous substances to indoor air, soil and water during the use stage
7.4.2 Soil and water

ILCD:
“Mandatory for both technical and non-technical target audience: ‘elementary flow categories’ by receiving/providing environmental compartment: ‘Emissions to water’.” “ISO 14044 names ‘emissions to air, water and soil’ as top-level classification, while recommending further differentiation as required for the given goal and scope of the LCA work.” ILCD Handbook: Framework and requirements for LCIA models and indicators: “This guidance document provides a framework and requirements for the models that are used to analyse the emissions into air, water and soil,…”
Guidance
 The boundary of Module B1 for buildings includes impacts such as release of substances from the façade, roof and other surfaces, which should be assessed according to the CEN/TC 351 standards.The release of dangerous substances should be provided for products exposed to soil and water after their installation in buildings during the use stage according to the horizontal standards issued from CEN TC 351, once these are available.The release of dangerous substances, expressed in mg/m2or kg per time unit and service life, should be assessed according to the CEN/TC 351 standards. The following draft documents are available: CEN/TC351/WG1/TS2 ‘Generic horizontal dynamic surface leaching test (DSLT) for determination of surface dependent release of substances from monolithic or plate-like or sheet-like building products’ and CEN/TC351/WG1/TS3 ‘Generic horizontal up-flow percolation test for determination of the release of substances from granular building products’ [CEN 2010b] (a third test method deals with the determination of the release of volatile organic compounds into indoor air by means of test chamber [CEN 2010c]). The robustness programme is in progress in 2012, and the validated standards should be available in 2013.A list of regulated dangerous substances possibly associated with building products under the Construction Product Directive (CPD) Regulation has been established at European level [EC 2011]. This list indicates which substances and parameters the evaluation should focus on . No aggregation is foreseen.For each pollutant, limit values are or can be defined at national level (at present only a few Member States have quantitative requirements on this issue, e.g. the Dutch ‘Soil Quality Decree’ [VROM 2007] and the German ‘Principles for assessing the effects of building products on soil and groundwater’ [DIBt 2009]). The results from these tests will be integrated into the CE marking scheme and make it possible to meet the RPC basic requirement No. 3 on hygiene, health and environment [EC 2005b]. They are complementary to the results obtained using the LCA methodology.Further work is necessary in order to establish scientific and pragmatic links between data obtained by an LCA approach (CEN/TC 350 work) and by using leaching tests (CEN/TC 351 work). Some proposals are available, as for example in [Lupsea 2012].For comparative assertions, simulation data are comparable if based on the same scenarios and hypothesis. All the parameters and hypotheses should be mentioned and explained together with the results in order to improve comparability.

B-24 Dynamic LCA data for assessing the impact of electricity consumption

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Aspect B-24 Dynamic LCA data for assessing the impact of electricity consumption
Description
 Energy sources for electricity production may vary significantly according to the season (winter or summer months), the day (weekdays, weekends) and the time within a day. Environmental impacts are strongly influenced by the decision to use annual energy data (i.e. average LCA data) or energy data based on a shorter period (monthly, daily or hourly).

related study objective

 ☒ stand-alone LCA ☒ comparative assertion

related study phase

 ☐ ☒ ☐ ☐ ☐
goal and scope definition inventory analysis (LCI) impact assessment (LCIA) interpretation reporting

relevant for
new buildings existing buildings construction products screening LCA simplified LCA complete LCA
Provisions Annual average datasets for electricity production should be used in the baseline scenario. Deviating data can be analysed in additional scenarios with transparent documentation and a sensitivity analysis.
Rules from:
 EN 15978:
Not mentioned
Guidance

Dynamic LCA data can be produced by using the hourly data provided by electricity suppliers in each national context. For example, in France, RTE provides hourly data, broken down by source: fossil, hydropower or nuclear energy Based on these proportions, and LCI/LCIA data corresponding to each energy source, dynamic LCA data can be calculated. (Note: the LCI/LCIA data statically aggregate elementary flows.)

Such dynamic LCA data can also be linked to models to predict the environmental impacts in a dynamic way (although very few LCA tools for buildings currently provide such assessment). More detailed information on this aspect can be found e.g. in a French PhD thesis by G. Herfray [Herfray 2011] or in [LoRe-LCA 2011]
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