B-11 (Buildings) / B-06 (Products) Definition of the service life of a building product

Aspect B-11 (Buildings) / B-06 (Products) Definition of the service life of a building product
Description
The lifespan, or service life, of building components and elements is usually defined as the period of time during which their performance meets or exceeds initial requirements. More detailed definitions can be found in reference work (e.g. the ISO 15686 series [ISO 15686] and [Guidance Paper F 2004] concerning the Construction Products Directive). Service life depends on many parameters, and is one subject of the ISO 15686 series.

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 service life of a product or building component has an influence on several aspects of the use stage of building LCA:

  • It should be taken into account for calculation of the frequency of replacement when the service life of the component is lower than the reference study period (refer to the aspect ‘Replacement frequency: whole number replacement cycles’ for further detail).
  • It should be provided with a maintenance scenario (and valid only under the conditions described with this scenario), as required by EN 15804 (annex A).
  • The performance of products and components usually declines gradually. Whenever possible, the loss of performance should be taken into account if it has an influence on other aspects of the use stage (e.g. modification of the performance of heating and cooling systems, insulation, etc. may have an influence on energy consumption).

The service life of a product or component is influenced by many parameters, notably the indoor and outdoor environments, maintenance level, design of the product, etc. (see ISO 15868-8 for further information). When providing information related to service life for an EPD, ISO 15804 requires that the intended use and in-use conditions of the product or system be specified and documented (EN 15804, Annex A).

When developing LCA at the building scale on the basis of several EPDs, it should be verified that the declared service lives and in-use conditions are compatible with the specifics of the building (notably its location and maintenance scenarios).

Only end of life related to loss of performance should be taken into account in the base-case scenario. End of life related to obsolescence (e.g. replacement of the product system by a newly developed or more efficient one before the end of life) may, however, be assessed in a complementary assessment. For more information on obsolescence please refer to ISO 15686-1 (Chapter 7).

Rules from:
EN 15978:
7.4.4.1 General

8.3 Time related characteristics
8.6.3 Scenarios for maintenance, repair, replacement

EN 15804:
6.3.3. Reference service life
7.3.3.1 B1–B5 use stage related to the building fabric
Annex A

Guidance
The RSL could be based on empirical, probabilistic or statistical data, but should always take into account the intended use (description of use) as described in ISO 15686-1, -2, -7 and -8 [EN 15804, Annex A].RSL should be determined on the basis of:

  • individual EPDs (cradle to gate with corresponding option, or cradle to grave);
  • client requirements and current practices;
  • product and component manufacturers’ information;
  • existing applicable standards such as ISO 15686-1, -2, -7 and -8;
  • the conventional service life in a national context or within an LCA software package for buildings.

It is expected that some service life data may be missing for the assessment at the building scale. In this case, several additional sources may be used to determine the service life of the product or system:

  • publicly available or commercial databases, including in some cases those related to whole-life costing;
  • research group publications and initiatives, such as the joint CIB/RILEM technical committee (CIB W080/RILEM TC 175-SLM);
  • scientific publications, e.g. from the DBMC conferences (International Conference on Durability of Building Materials and Components). More publications are available from the ICONDA database).

For building products, it may be useful to use conventional values for the respective product category (e.g. in a national context or within an EPD programme), if available. For example, the EOTA guide in Europe states some commonly agreed service lives:

  • 10 years for easily replaceable products (e.g. paints);
  • 25 years for products that can be replaced with some minor effort (e.g. façade, windows, building-integrated photovoltaics, etc.);
  • 50 years for products that are difficult to replace (e.g. thermal break);
  • 100 years for irreplaceable products (e.g. structural bricks, concrete columns, etc.).

Refer to the aspects ‘Distinction between Modules B2, B3, B4 and B5’ and B-14 ‘Replacement frequency’ for further guidance on how to interpret and use RSLs for product and building LCA.


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