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

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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-03 Accounting for technical building equipment – complete LCA

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Aspect

A-03 Accounting for technical building equipment – complete 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 complete LCA, technical building equipment should be included. If LCA or EPD data are available at the European or national level, they should be included using specific data (e.g. based on industry EPD); otherwise, if no specific data are available for the context of the study, generic data should be used as proxy.This aspect is considered in accordance with the LCA study type: all of the technical equipment should be included in the context of a complete LCA, unless they fall under cut-off criteria.
Rules from:
 EN 15978:7.5.2 Description of the physical characteristics of the building
Guidance
 The practitioner should use detailed calculation for complete LCA based on specific data (e.g. EPD), or else generic data (e.g. taken from generic LCA databases) for the technical systems:

  • sanitary systems (water, waste water, piping, pump and fixed equipment);
  • fixed firefighting systems;
  • heating and hot water systems;
  • mechanical ventilation and air conditioning;
  • fixed lighting systems;
  • electrical supply systems (small power, wiring, etc.);
  • communication and security systems;
  • transportation inside the building (lifts, escalators);
  • drainage system; etc.

The practitioner should be aware that these elements of a building can have a significant impact.

Studies in the UK have estimated that the as-installed embodied impact of mechanical and electrical services is a little over 100 kg CO2e/m2 in offices, but can be as high as 240 kg CO2e/m2, with proportions of as-built embodied carbon for all buildings ranging from 4% to 25%, depending on building type. Similar conclusions were reported in the French HQE performance study [Lebert 2012], and in a recent scientific paper.

Back to 4.2. Module A1 – A3

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

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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-05 Transport of products to the construction site – complete LCA

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Aspect

A-05 Transport of products to the construction site – complete 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 Transport of products to the construction site should be included for complete LCA.The practitioner should use specific transport distances and load factors, or average distances and load factors if data are missing. The rules provided in EN 15804 should be applied. 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 these 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
 The practitioner should use specific data, such as that available in national EPD programmes (e.g. such specific data are available in France). Data on distance traveled and mode of transport (road, rail, sea container etc.) should be collected for each input material and waste generated. Transports should be covered all the way from the producer or to waste treatment, not just from a depot or storage warehouse. For example, the transport of timber from the sawmill in Scandinavia should be included, not just from the local timber merchant’s depot. Unless transport is likely to be very significant, generic datasets for transport per tonne-kilometre can be used. These take account of typical vehicle size, fuel efficiency, typical loading, and percentage of empty return journeys. More detailed data on the number of deliveries, size of truck, Euroclass, actual load, return journey etc. can be gathered and used to generate more specific data, but this is rarely useful unless the transport phase is particularly important. Impacts of waste that is created within the transport phase should be considered. This means that if material is wasted during this phase, its manufacturing impact and the impacts of disposal should both be considered in Module A4.

1) Specific guidance for building LCA studies
Specific distances should be collected and used for complete LCA of buildings, otherwise default average transport distances of 300 km can be assumed for all building products, based on previous works [Nemry 2008; Lasvaux 2010]. However, most building products, particularly bulk products such as aggregates and 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
The practitioner interested in obtaining detailed guidance on transport distances and load factors of lorries can look for PCR documents of national EPD programmes, and in national transport statistics.

6.4 Module A5 – Construction installation process

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6.4  Module A5 – Construction installation process

A-06 Construction installation process impacts for screening LCA

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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).

Breakdown of impacts for a given indicator for one building type

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 (Iproduct).

2) Determine a ratio (default value) Ri, 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): Ii = Iproducts × Ri.

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

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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-08 Land preparation and earthwork during the construction process – complete LCA

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Aspect A-08 Land preparation and earthwork during the construction process – complete 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 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 building products screening LCA simplified LCA complete LCA
Provisions The land preparation and earthwork should be included in complete LCA if they are 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).
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 detailed calculation (based on specific  data) for complete LCA. The impact of land preparation and earthwork can be assessed using generic data accounting for the impact of the fuel consumption of construction machinery (e.g. skid-steer loaders or bulldozers).This aspect can be neglected for most construction projects, as it is of minor relevance.

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

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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.