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B-14 Replacement with simplified LCA

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Aspect B-14 Replacement with simplified LCA
Description
 The replacement module covers the complete replacement of components and building parts if their reference service life is lower than the reference study period. Replacement is mandatory for a limited set of building parts and components in the context of a 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 construction products screening LCA simplified LCA complete LCA
Provisions The replacement procedure refers only to planned action in response to anticipated losses of performance of building components and building parts. Replacements should be considered when the reference service life (or eventual design life) of a product or building part is lower than the reference study period.The replacement scenario should cover at least the elements in the following list (item marked with a * are suggested):

  • roof*;
  • windows*;
  • floor finishes and coverings*;
  • refrigeration* and coolants;
  • decorative wall finishes and coatings (e.g. wallpaper, paints);
  • doors;
  • heating, cooling and lighting equipment, and any power-generating equipment (e.g. wind turbines, PV or solar heating)*;
  • equipment for internal transport (e.g. lifts, escalators)*;
  • water and sewerage systems;
  • electrical distribution system.

The replacement of load-bearing structure, exterior and basement walls, floor slabs and foundation should not be considered unless justified, as it usually entails significant building modification.

In any case the boundaries of the maintenance scenario should be clearly stated.

A replacement scenario at the building scale should be determined on the basis of:

  • individual EPD (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 [ISO 15686].

Building modifications in response to unexpected events (e.g. flood, inappropriate use or vandalism) should be considered as reparation (B3), and are thus optional in the context of a simplified LCA.

According to EN 15978, the boundary for replacement should include:

  • production of the replaced component and ancillary products;
  • transportation of the replaced component and ancillary products, including production impacts and the aspects of any losses of materials during transportation;
  • the replacement process for the replaced components and ancillary products;
  • waste management of the removed component and of ancillary products;
  • the end-of-life stage of the removed component and of ancillary products.

However, in the context of a simplified LCA, only the production of the replaced component need be included.

The frequency of replacement may be determined according to the ‘replacement frequency’ aspect of the present guide.
Rules from:
 EN 15978:7.4.4.1 General

7.4.4.5 Boundary for replacement (Module B4)

8.3 Time related characteristics

8.6.3 Scenarios for maintenance, repair, replacement

EN 15804:

6.3.3. Reference service life

6.3.4.4.2 – B4 Replacement

7.3.3.1 B1–B5 use stage related to the building fabric

Annex A
Guidance
 The overall replacement scenario should be consistent with respect to the building structure (e.g. replacement of coating is mandatory when replacing the support).In addition, LCA of an existing building should take into account actual and established practices (real-life data) specific to that particular building.As replacement scenarios are based on the RSLs of building components and building parts, it should be noted that the RSL could be based on empirical, probabilistic or statistical data, and should always taking into account the intended use (description of use) as described in ISO 15686-1, -2, -7 and -8 [EN 15804, Annex A]. Furthermore, a component manufacturer cannot be held responsible for the actual design of the building or the use and application of the product, environment, workmanship or use [EN 15804, Annex A].

Thus:

  • The overall replacement scenario should be consistent with the maintenance scenario.
  • Both maintenance and replacement scenarios should be based on reliable service life data, either included in the EPD, directly provided by the manufacturer, or based on sound research work.

For an existing building, if a component has failed before its reference service life because of inappropriate maintenance, it may be considered as belonging to the repair module instead.

B-15 Replacement with complete LCA

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Aspect B-15 Replacement with complete LCA
Description
 The replacement module covers the complete replacement of components and building parts if their reference service life is lower than the reference study period.

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 replacement procedure refers only to planned action in response to anticipated losses of performance of building components and building parts. Replacements should be considered when the reference service life (or eventual design life) of a product or building part is lower than the reference study period.A replacement scenario at the building scale should be determined on the basis of:

  • individual EPD (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 [ISO 15686].

Building modifications in response to unexpected events (e.g. flood, inappropriate use or vandalism) should be considered as reparation (B3).

According to EN 15978, the boundary for replacement should include:

  • production of the replaced component and ancillary products;
  • transportation of the replaced component and ancillary products, including production impacts and the aspects of any losses of materials during transportation;
  • the replacement process for the replaced components and ancillary products;
  • waste management of the removed component and of ancillary products;
  • the end-of-life stage of the removed component and of ancillary products.

Water and energy usage related to the replacement process should always be included.

The frequency of replacement should be determined according to the ‘replacement frequency’ aspect of the present guide.
Rules from:
 EN 15978:
7.4.4.1 General
7.4.4.5 Boundary for replacement (Module B4)
8.3 Time related characteristics
8.6.3 Scenarios for maintenance, repair, replacement

EN 15804:

6.3.3. Reference service life

6.3.4.4.2  – B4 Replacement

7.3.3.1 B1–B5 use stage related to the building fabric

Annex A
Guidance
 The overall replacement scenario should be consistent with respect to the building structure (e.g. replacement of coating is mandatory when replacing the support). In addition, LCA of existing building should take into account actual and established practices (real-life data) specific to that particular building.As replacement scenarios are based on the RSLs of building components and building parts, it should be noted that the RSL could be based on empirical, probabilistic or statistical data, and should always taking into account the intended use (description of use) as described in ISO 15686-1, -2, -7 and -8 [EN 15804, Annex A]. Furthermore, a component manufacturer cannot be held responsible for the actual design of the building or the use and application of the product, environment, workmanship or use[EN 15804, Annex A].Thus:

  • The overall replacement scenario should be consistent with the maintenance scenario.
  • Both maintenance and replacement scenarios should be based on reliable service life data, either included in the EPD, directly provided by the manufacturer, or based on sound research work.

For an existing building, if a component has failed before its reference service life because of inappropriate maintenance, it may be considered as belonging to the repair module instead

For a new building, replacement frequency and more generally the replacement scenario should be based on service life planning and service life prediction, as described by ISO 15686 series [ISO 15686]. It should be noted that: service life planning can only address foreseeable changes. Since service life planning is concerned with foreseeable risks, it is not applicable to the estimation of obsolescence […] or to defective performance resulting from unforeseeable events or processes [ISO 15686-1, part B.8.2.]. Both cases may be accounted for in the case of existing buildings whenever specific data are available.

The progressive loss of performance of some components has an impact on the overall behaviour of the building (e.g. loss of performance of insulation may lead to an increase of energy demand due to heating). If sufficient data are available these aspects should be addressed by using a sensitivity analysis.

B-16 Refurbishment for screening, simplified and complete LCA

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Aspect B-16 Refurbishment for screening, simplified and complete LCA
Description
 Refurbishment activities refer to the change of major elements or change of use in a building.Do we need to take refurbishment into account in a building 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 Refer to provisions in the aspect ‘Distinction between Modules B2, B3, B4 and B5’.
Rules from:
 EN 15978:
7.4.4.1 General
7.4.4.6 Boundary for refurbishment (Module B5)
8.3 Time related characteristics
8.6.4 Scenarios for refurbishment

EN 15804:

6.3.4.4.2 B1–B5 Use stage information modules related to the building fabric:

7.3.3.1 B1–B5 Use stage related to the building fabric
Guidance
 Refer to guidance in the aspect ‘Distinction between Modules B2, B3, B4 and B5’. For example, it is recommended that a refurbishment scenario be developed in the case of a significant reference study period (>100 years); as modification of the building use is expected over such a period of time. A refurbishment scenario could also be developed if the reference study period is higher than the reference service life of load-bearing components and structural elements.

7.7 Module B6 – Operational energy use.

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7.7  Module B6 – Operational energy use.

B-20 Operational energy demand for existing buildings – Boundaries and scenarios

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Aspect B-20 Operational energy demand for existing buildings – Boundaries and scenarios
Description
 Several parameters can influence the results of the energy demand at the operational stage of buildings. Among others, the selection of uses (i.e. building-related or non-building-related uses) has a major significance on the energy demand. European standards (EN 15804/EN 15978) recommend that priority be given to taking building-related uses into account; however, it is obvious that non-building-related appliances significantly influence the energy needs of building-related uses (e.g. the thermal gain of appliances decreases the level of heating demand). Moreover, the global gain obtained by technology mixing building energy uses and non-building-related uses (e.g. appliances such as dishwashers and washing machines using domestic hot water produced by solar thermal panels) can be taken into account only if all operational energy uses are also considered into the assessment. The following section aims at providing guidance for screening, simplified and complete LCA of existing buildings.

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 For existing buildings, measured historical data consumption should be used, if available and applicable. Building-related uses and non-building-related uses may be taken into account according to the goal and the scope of the study.
Rules from:
 EN 15978:
7.4.4.7 Boundaries for operational energy use
8.6.5 Scenarios for operational energy use – Module B6
Guidance
 For existing buildings, if measured historical data consumption are available and applicable (i.e. the objective and the scope of the study are consistent with available data, and future changes in the existing building will not impact on the energy uses), they should be used to calculate the energy demand.Note: the level of detail of energy measurement should allow its use for LCA assessment (i.e. the breakdown of the operational energy demand should be available for each energy carrier). When measured data are available for each energy carrier, building-related and non-building-related uses should be accounted for, as energy monitoring usually does not permit uses to be differentiated. This applies to screening, simplified and complete LCA. For the calculation of energy demand of building-related uses, methods and tools developed by EPA-NR projects may be used.

B-22 Operational energy demand for existing buildings – Consideration of user behaviour

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Aspect B-22 Operational energy demand for existing buildings – Consideration of user behaviour
Description
 Several parameters influence the results of the energy calculation demand at the operational stage of buildings. Among others, user behaviour may have a major significance on the energy needs. The following section aims at providing guidance for screening, simplified and complete LCA of existing buildings, and the possibility of taking user behaviour into account regarding the goal and the scope of the 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 construction products screening LCA simplified LCA complete LCA
Provisions For existing buildings, if measured consumption data are available and applicable for the LCA analysis, user behaviour should be taken into account. Otherwise, the same guidance as for new buildings should be applied.
Rules from:
 EN 15978:8.6.5 Scenarios for operational energy use – Module B6
Guidance
 For stand-alone LCA of existing buildings, if measured historical consumption data are available and applicable (i.e. the objective and the scope of the study are consistent with available data, and future changes in the existing building will not impact on the energy uses), they should be used to calculate the energy demand.Otherwise, scenarios should reflect statistical or conventional user behaviour. Scenarios reflecting specific user behaviour may be used, but sensitivity analysis should be performed in order to provide evidence of the significance of this deviation. For comparative study of refurbishment alternatives for existing buildings, four different types of operation should be considered:

  • rehabilitation;
  • reference rehabilitation;
  • complete demolition and new construction;
  • maintenance of an existing building (maintain performances during a given period).

A rehabilitation operation consists of a deconstruction operation (removal of products) and a reconstruction operation (adding new products to replace discarded ones). Reference rehabilitation is a generic rehabilitation that implies the use of standard construction materials, designs and processes.

If historical data and/or energy monitoring and reflecting user behaviour (e.g. number of users, occupancy scenario etc.) are available, and if they are applicable (i.e. alternatives for refurbishment do not consider a change of use or other major modification of building systems or occupancy) , then scenarios derived from such data should be used to calculate the energy demand for each alternative.

Otherwise, scenarios should reflect statistical or conventional user behaviour. The same scenario should be used for each alternative.

B-23 Operational energy calculation – Allocation of energy production for on-site systems connected to grid”

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Aspect B-23 Operational energy calculation – Allocation of energy production for on-site systems connected to grid”
Description
 Current new buildings may not only be energy-efficient, but can also produce energy on site in multiple ways.The energy produced on site may not only be consumed inside the building, but can also be exported. When energy is produced on site by grid-connected systems (photovoltaic, wind turbines, boiler connected to heating grid etc.), how is this calculated? How are the impacts allocated for both product aspects (e.g. PV cells) and operational energy production?

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 principles for the calculation of exported, imported and on-site energy production should be consistent with the provisions of EN 15978 (see especially reference cases, annex B).

  • Additional provisions for grid-connected systems: the boundaries (i.e. energy uses included) for the calculation of energy demand and exported energy should be homogeneous.
  • The calculation of exported energy and energy consumed on site should consider simultaneity between the consumption and the production.

The method for allocating environmental impact for product aspects and operational aspects should be consistent with the guidance in EN 15978.
Rules from:
 EN 15978:
7.4.4.7 Boundary of the operational energy use (Module B6)
8.6.5 Scenarios for operational energy use (Module B6)Annex B (informative) Exported energy – Case studiesILCD:

6.8.4 Time-related representativeness

Guidance
 The methods for energy calculation should be consistent with the reference cases proposed in annex B of EN 15978.Supplementary recommendations are proposed for on-site energy-producing systems that are connected to the grid (case 3 of EN 15978), as follows.Boundaries for the calculation
The boundaries chosen for calculation of the energy demand should be consistent with those for calculation of the exported energy: if only building-related uses are included, the amount of energy that does not supply the uses considered should be considered as exported energy. Then two situations may be considered:

  1. Including only building-related uses in the scope of the assessment: other non-building-related uses are not accounted. The exported energy will be calculated without considering the energy demand for non-building-related uses, because these are considered to be beyond the system boundary.
  2. Including both building-related uses and non-building-related uses in the scope of the assessment: the two uses are taken into account for the calculation of exported, imported and on-site consumed energy.

Timescale for the energy calculation

For simplified and complete LCA, an hourly scale should be used in order to take into account simultaneity between energy demand and the on-site energy production.

The annual exported energy, imported energy and on-site energy consumption for the considered energy carrier i may be calculated as follows:

 where:

  • Energy production i,h is the amount of energy produced by building on-site systems at hour h for energy carrier i.
  • Energy demand i,h is the amount of  energy needed for the considered building energy use at hour h for energy carrier i.

Allocation of environmental data

Rules should be consistent with EN 15978 for both product and operational aspects.

For imported energy (Module B6) and exported energy (Module D) more representative environmental data should be used. For example. for electricity, hourly environmental data should be used in preference to monthly or annual average data. See the corresponding aspect ‘Dynamic LCA data for assessing the impact of electricity consumption’.

 

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]