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

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].


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