Tag: Study type: Screening LCA

A-02 Accounting for technical building equipment – screening and simplified LCA

Written on 22. October 2012.

*Aspect*		*A-02 Accounting for technical building equipment – screening and simplified LCA*
*Description*		Different types of technical building equipment can be included in building LCAs: e.g. boilers for heating, air-conditioning systems for cooling, duct networks for ventilation, solar panels for hot water, lifts, lighting etc. The development of energy-efficient buildings has meant that the relative share of the embodied impacts has recently increased, leading to more consistent modelling of the related impacts of building products and technical equipment. In addition, the LCA model should be consistent: if, for example, the PV-related energy consumption is included within Module B6, then the impacts of the PV manufacture should be accounted for in Modules A1–A3.
*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*	For screening and simplified LCA, accounting for technical building equipment is optional, owing to potentially missing data.If LCA or EPD data are available for technical equipment (e.g. in generic LCA databases) at the European or national level, they should be included, using these data as default values.
*Rules from:*	*EN 15978*:7.5.2 Description of the physical characteristics of the building
*Guidance*	The practitioner should use default values for the technical building equipment for screening and simplified LCA. Such default values should come from available LCA generic databases (e.g. Ecoinvent, ELCD, ESUCO), or otherwise may be defined with the relevant stakeholders.

A-02 Transport of staff in the supply of raw materials

Written on 22. October 2012.

Aspect

A-02 Transport of staff in the supply of raw materials

Description

Is it relevant to consider the transport of staff during the extraction and manufacturing life cycle stages?

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

Typically, the transport of staff is not included, owing to its lack of significance in relation to the use of energy within the cut-off rules. National EPD programmes may have individual rules on this matter, and for improved consistency with the EPDs of one programme (e.g. of the national EPD programme),it may be advisable to apply such rules.

Rules from:

EN 15804

6.3.5 Criteria for the exclusion of inputs and outputs

Guidance

Screening and simplified LCA: Transport of staff in the supply of raw materials should not be included.Complete LCA: Unless the energy used for transport of staff for any individual process is likely to exceed 1% of the primary energy requirement for that process, it is not necessary to collect data from staff on their journey to and from the extraction or manufacturing site. Significance could be reviewed if necessary by considering costs as a proxy for primary energy, although it should be recognized that petrol and diesel are often highly taxed relative to electricity and natural gas.

A-03 Transport of raw materials to the manufacturer

Written on 22. October 2012.

Aspect

A-03 Transport of raw materials to the manufacturer

Description

Several raw materials are needed for manufacturing a building product. Depending on the number of raw materials and the availabilities of information from the suppliers, it may be difficult to account for the transport of raw materials in an accurate way. However, this stage of the life cycle may be relevant if the suppliers are located far away from the manufacturing plant.How should the transport of raw materials to the manufacturer be considered for a product 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

Transport of raw materials to the manufacturer should be included in Module A2 though it may be considered not relevant according to the cut-off rules (e.g. from EN 15804). Concerning the use of data, the provisions on data quality as given above should be considered (data quality, ILCD entry level, use of consistent data sources for comparative assertions).

Rules from:

EN 15804

6.3.4.2 Product stage

Guidance

Within Modules A1–A3, transport is generally a significant impact only for materials with very low manufacturing impact – aggregates and timber, for example. Module A2 includes only transport to the manufacturing site from the previous production or extraction process. Earlier transport journeys are included in Module A1. Module A2 is mandatory in any cradle-to-gate EPD. National EPD programmes may have more specific rules on this topic. The main issue for the practitioner is collection of data on the distances between suppliers and the manufacturer. Generally speaking, these data should be available, and should be requested. However, if data are missing, it is recommended that default values, e.g. from national EPD programmes and PCR, be used; otherwise the practitioner’s own default values should be used (which should be subjected to sensitivity analysis).

A-04 Transport of products to the construction site – screening and simplified LCA

Written on 22. October 2012.

*Aspect*		A-04 Transport of products to the construction site – screening and simplified LCA
*Description*		This aspect is related to the transport of building products from the manufacturer’s production plant (or from regional storage) to the construction site. In practice, the assessment of transportation impact depends on the number of manufacturers or the number of regional storage providing a given building product. Such detailed information may be impossible to obtain without close cooperation with the building industry.Should the transport of products to construction site be included? What could the transportation distance be for each building product? Should losses be allowed for?
*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*	For screening and simplified LCA, transport to the construction site is optional, because of both potentially missing data and minor relevance at the scale of full building LCAs.If data are available, transport of products to the construction site may be included in a screening or simplified LCA unless they fall under the cut-off rules. The practitioner should use average transport distances and load factors. Rules should follow the recommendations of EN 15804. This includes the impacts of the transport and the impacts of any transport-related losses of material and its disposal (i.e. the impact of manufacturing material that is wasted as a result of transport, and the impact of disposing of the waste). Losses should be documented, where they occur.
*Rules from:*	*EN 15978: 7.4.3.2 Boundary of the Transport to and from site (Module A4) EN 15804:* 6.2.3 A4-A5, Construction process stage, information modules
*Guidance*	Modelling of the life cycle stage ‘Transport to the site’ should be iterative, and linked to corresponding cut-off rules defined e.g. in EN 15804/EN 15978. 1) Specific guidance for building LCA studies For building LCA, transport may be not significant in terms of environmental impact, allowing proxy data to be used. As a default transport distance, average transport distances of 300 km can be assumed for all building products, based on previous work [Nemry 2008]; [Lasvaux 2010]. However, most building products, particularly bulk products such as aggregates or ready-mixed concrete, are likely to travel shorter distances. For example, Eurostat freight transport statistics show that, for almost all member states, more than 50% (by mass) of ‘Other non-metallic mineral products’ travel less than 50 km per trip. 2) Specific guidance for product LCA studies Previous studies have shown that for cradle-to-grave product LCA transport represents up to 15% of the usual life cycle impact indicators in median values [Lasvaux 2010]. The highest share is for the photochemical ozone potential (POCP), this indicator being more linked to air emissions of lorries than the other ones. Other studies have shown for ‘cradle-to-gate with options data’ (including only transportation to the building site and the construction installation process related to the product) that transport is of relevance, as well as the ancillary products, compare with minor aspects, such as cutting waste or the building process [Kellenberger 2009]. Other studies, e.g. from the UK, have estimated that carbon emissions from freight transport of building products represent at least 5% of the embodied carbon from manufacture. For building LCA (accounting for replacement of building products during the use stage and the end of life), it does not represent more than 5% of the non-renewable primary energy, owing to the higher share of the use phase in building LCAs, based on a French case study [Lasvaux 2010].

A-06 Construction installation process impacts for screening LCA

Written on 22. October 2012.

*Aspect*		A-06 Construction installation process impacts for screening LCA
*Description*		Construction site impacts are driven mainly by the groundworks (fuel consumption), the transport of products, water and energy consumption (e.g. electricity), and the capital goods (such as crane, bungalow etc.), but also by the transport of construction workers. Under specific goal and scope, it might be interesting for a construction company or a building designer to assess the impacts of Module A5 by means of a default approach, without looking in detail at the different aspects, such as land preparation, water, energy and capital goods.
*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 assessment of construction site impacts may be taken into account in screening LCA by means of a default approach using global default values for Module A5. The intended use of this methodology is to get an overview of the share of impact of Module A5 when considering the full building LCA. If the results are sensitive to Module A5, the practitioner should refer to a more detailed assessment.
*Rules from:*	*EN 15978: 7.4.3 Boundaries of the construction process stage* 8.5 Scenarios for the construction process stage (Modules A4–A5)
*Guidance*	During the design of a building, it may be difficult to assess the information for land preparation, water and energy consumption, owing to the lack of data. However, information on the quantities of building products are information available upstream of a building project from the construction companies. One possibility is then to assess the construction site impacts from the building product impacts, for which the level of detail is comparatively higher. Such a rough estimation may be sufficient for some screening LCA studies of buildings. It is not necessary to define default values at the level of each impact source for Module A5, which considerably reduces the level of complexity in the first step of a building LCA study.The link between this information needs default values to be provided based on statistical studies for each building type or construction system. Figure 14 represents a theoretical example, for one environmental indicator and for one building type and construction system, of the share of impact between the building products and the four aspects of the construction site taken as examples in this guidance (energy, water, transport of workers, and capital goods). Figure 16: Breakdown of impacts for a given indicator for one building type The calculation steps required to derive the example results in Figure 14 might be as follows: 1) Calculate the impacts related to the building products (I_product). 2) Determine a ratio (default value) R_i, expressed as a percentage, for each aspect i of the construction site (energy, water, transport of freight, and capital goods). These default values can be derived from statistical studies of meter readings of representative construction sites, as well as for the building product impacts. It is then possible to assess the impact of aspect i of the construction site by means of the global impact of the building products and the ratio (default value): I_i = I_products × R_i. Such a methodology may be followed by the LCA practitioner, and adapted according to the goal and scope of the study. To obtain representative ratios (default values), the LCA practitioner or LCA tool developer would need to work closely with or contact the construction companies to make such default values available.

A-07 Land preparation and earthwork during the construction process – screening and simplified LCA

Written on 22. October 2012.

*Aspect*		*A-07 Land preparation and earthwork during the construction process – screening and simplified LCA*
*Description*		This aspect relates to the impact of site preparation, including the fuel consumption of, for example skid-steer loaders or bulldozers during the groundworks and landscaping. Under the specific goal and scope, this aspect might be interesting for, say, a construction company that needs to identify the hotspots of its construction site. Should the land preparation and earthwork during the construction process be considered in the context of a screening or 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
*relevant for*
	new buildings	existing buildings	building products	screening LCA	simplified LCA	complete LCA
*Provisions*	The land preparation and earthwork may be included in screening and simplified LCA if they are relevant to the goal and scope of the study (e.g. a construction company might have more interest than a building designer in this aspect).
*Rules from:*	*EN 15978: 7.4.3 Boundaries of the construction process stage* 8.5 Scenarios for the construction process stage (Modules A4–A5)According to the rules from EN 15978, the system boundary for the construction process shall include the groundworks and landscaping
*Guidance*	The practitioner should use default values (e.g. ratios or generic data) for screening and simplified LCA, and also refer to cut-off rules. Ratios can be defined with stakeholders. This aspect can be neglected for most construction projects, as it is of minor relevance.

Back to 4.4. Module A5

A-09 Product storage on site before installation – screening and simplified LCA

Written on 22. October 2012.

*Aspect*		A- 09 Product storage on site before installation – screening and simplified LCA
*Description*		Storage of products on arrival at site before installation includes such aspects as maintaining specific temperature or humidity in a storage space on site, and protection from weather, vandalism, theft, etc. Under the specific goal and scope this aspect might be interesting for, say, a construction company that needs to identify the hotspots of its construction site. Should the storage of products be considered in the context of a screening or 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
*Relevant for*
	new buildings	existing buildings	building products	screening LCA	simplified LCA	complete LCA
*Provisions*	Product storage on site before installation may be included in screening and simplified LCA if it is relevant for the goal and scope of the study (e.g. a construction company might have more interest than a building designer in this aspect).If there are impacts from product storage (e.g. maintaining specific temperature or humidity conditions in a storage space on site) then this may be included in Module A5 next to the infrastructures required for the product storage (e.g. protection from weather, vandalism, theft), but these can be evaluated for significance using the cut-off rules.Any wastage because of poor product storage should be accounted for in Module A5 (manufacture, transport and disposal of wasted material).
*Rules from:*	*EN 15978: 8.5 Scenarios for the construction process stage (Modules A4–A5)*
*Guidance*	The practitioner should use default values (ratios) for simplified LCA. Such data can be defined with stakeholders. This aspect can be neglected for most construction projects, as it is of minor relevance.

A-11 Transport of construction workers – screening and simplified LCA

Written on 22. October 2012.

*Aspect*		A-11 Transport of construction workers – screening and simplified LCA
*Description*		This aspect concerns the transportation of construction workers from home to work and to the construction site. Under specific goal and scope, this aspect might be interesting for, say, a construction company that needs to identify the hotspots of its construction site.
*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 transport of construction workers may be included in screening and simplified LCA if it is relevant for the goal and scope of the study (e.g. a construction company might have more interest than a building designer in this aspect).Transportation of workers to construction site may be included for screening and simplified LCA if it is in the focus of the study. Refer to cut-off rules, and use default values (such as ratios).
*Rules from:*	*EN 15978: No specific rule is defined (8.5 Scenarios for the construction process stage (Modules A4–A5))*
*Guidance*	The practitioner should use default values (generic data, ratios) for simplified LCA. Such data can be defined with stakeholders.This aspect may be neglected for most building LCA studies, because it may fall outside the goal and scope. However, specific building stakeholders, such as construction companies, may have a special interest and thus will take it into account.If taken into account, this aspect is likely to fall under cut-off-rules for most construction projects. Such a statement should be supported through detailed studies of the construction stage. It will be revised if more evidence is available.

A-13 Transport of construction machinery to the building site – screening and simplified LCA

Written on 22. October 2012.

*Aspect*		A-13 Transport of construction machinery to the building site – screening and simplified LCA
*Description*		This aspect concerns the transportation of machinery necessary for the construction of a building from the storage place to the construction site. Under specific goal and scope, this aspect might be interesting, e.g. for a construction company that needs to identify the hotspots of its construction site.
*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 transportation of construction machinery to the building site is optional, owing to both potentially missing data and minor relevance. It may be included in screening and simplified LCA if it is relevant for the goal and scope of the study (e.g. a construction company might have more interest than a building designer on this aspect).If the transportation of construction machinery is accounted for, rules for its estimation should follow the recommendations of EN 15804. In this case, practitioners should refer to the cut-off rules, and use default values (ratios) for the transportation distances and load factors.
*Rules from:*	*EN 15978: No specific rule is defined (8.5 Scenarios for the construction process stage (Modules A4-A5)) EN 15804:* No specific rule is defined (6.3.4.3 Construction stage)
*Guidance*	The practitioner can use default values (ratios) defined with stakeholders for screening and simplified LCA.This aspect may be neglected for most construction projects, owing to its minor relevance.

A-15 Installation of the product into the building – screening and simplified LCA

Written on 22. October 2012.

*Aspect*		A-15 Installation of the product into the building – screening and simplified LCA
*Description*		The installation of products into the building needs ancillary materials and processes (e.g. energy). What should be taken into account during the installation stage (e.g. drills, screwdrivers)?
*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 inclusion of ancillary materials should follow EN 15804/EN 15978. This information should be available in construction product datasets or EPD data that are compliant with EN 15804.The energy and related emissions from the construction tools and installation materials should follow EN 15978. They may be omitted for screening and simplified LCA studies, owing to their minor relevance.
*Rules from:*	*EN 15978:* 8.5 Scenarios for the construction process stage (Modules A4-A5)EN 15804: 6.2.3. A4–A5, Construction process stage, information modules 7.3.2. Construction process stage
*Guidance*	General guidance for product LCA studies (e.g. EPD) According to both EN 15804 and EN 15978, the installation of products into the building, including ancillary materials and their related processes, should be taken into account. The practitioner should comply with EN 15804 as far as possible, assuming the provisions are sufficiently clear. If an aspect is not clearly defined in the standard (e.g. there is so far no list of ancillary materials for the different applications of building products), the practitioner should always document assumptions made concerning the inclusion of ancillary materials. Specific guidance for product LCA studies (e.g. EPD) For cradle-to-grave product LCA, the practitioner needs to combine a cradle-to-gate LCA with some LCA data for ancillary materials implemented in the construction stage in order to fulfil the functional unit. For example, for cradle-to-grave EPD of a glued laminated timber beam in a building, the functional unit can be as follows: the function ‘support the structural elements from the roof for 100 years’ is defined for 1 ml of a beam of 5 m for a cross-section of 0.3 × 0.1 m. The ancillary materials in this case might be galvanized steel bolts, for example. The impacts related to their manufacture and transport to the site should be allocated to Module A5, as they are not primary raw materials in the wooden beam manufacturing process. However, in other cases, e.g. ready-mixed concrete assembled on site with reinforcing steel, as these two raw materials are not ancillary materials the impacts of their manufacture and transport to the site should be allocated to Modules A3 and A4 respectively. For other specific cases it may be tricky. For example, for ceramic tiles that need on-site mortar to be installed in the building, the allocation of the impacts of the mortar may be not clear, as it depends on the status of the mortar: is it a raw material next to the ceramic tiles (impact allocated to Modules A1–A3) or only an ancillary product (impact allocated only to Module A5)? The more the environmental impacts of ancillary materials (related to manufacturing and transport to the site) are allocated to Module A5, the more relative impact this life cycle stage will have compared with production and end-of-life. It should be emphasized that the ancillary materials’ upstream impacts are not direct impact of a construction site. In this context, the results for Module A5 should be interpreted accordingly. Specific guidance for building LCA studies If relevant for the goal of the study, use ratios (generic data) for screening and simplified LCA, though the ancillary materials may be omitted, because of their minor relevance.