7.7 Module B6 – Operational energy use.
7.7 Module B6 – Operational energy use.
Tag: Lifecycle stage: B6
7.7 Module B6 – Operational energy use.
7.7 Module B6 – Operational energy use.
- B-17 Operational energy demand for new buildings – Boundaries and scenarios for screening LCA
- B-18 Operational energy demand for new buildings – Boundaries and scenarios for simplified LCA
- B-19 Operational energy demand for new buildings – Boundaries and scenarios for complete LCA
- B-20 Operational energy demand for existing buildings – Boundaries and scenarios
- B-21 Operational energy demand for new buildings – Consideration of user behaviour
- B-22 Operational energy demand for existing buildings – Consideration of user behaviour
- B-23 Operational energy calculation – Allocation of energy production for on-site systems connected to grid”
- B-24 Dynamic LCA data for assessing the impact of electricity consumption.
B-08 Modelling of energy use
| Aspect | B-08 Modelling of energy use | |||||||
Description |
Is B6 relevant at a product level? How should the operational energy use be modelled? | |||||||
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related study objective |
☒ stand-alone LCA | ☒ comparative assertion | ||||||
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related study phase |
☒ | ☐ | ☐ | ☐ | ☐ | |||
| goal and scope definition | inventory analysis (LCI) | impact assessment (LCIA) | interpretation | reporting | ||||
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relevant for |
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 |
 |
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| new buildings | existing buildings | construction products | screening LCA | simplified LCA | complete LCA | |||
Provisions |
Energy used by products during the use stage should be assessed in terms of importance. For a product, a scenario may be defined if the product is relevant for the energy supply of a building. However, the actual operational energy use can only be given for a building; data for this module for products are always based on a specific scenario, and do not necessarily apply to other situations. | |||||||
Rules from: |
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Guidance |
The regulated energy use (the energy use covered by national building regulations in Member States) of building-integrated technical systems is determined by the design of the building and the use of the building.Regulated energy use reported in Module B6 would normally be provided at a building level through modelling with the relevant national system derived from the Energy Performance in Buildings Directive.At a product level, it is not possible to model the relevant regulated operational energy use related to the product, because it is dependent on all the other parts of the building, although the product could be included within a ‘model’ building and a building assessment undertaken.
If a product requires non-regulated energy to use it – for example a blind that requires electricity for operation, or an intelligently glazed panel that requires electricity to switch to clear from opaque, or a grey water system that requires energy for pumping – then this energy use should also be modelled in Module B6. This would need to be based on a scenario for use, such as the number of operations per day. The results of Module B6 should be separated from the other modules. Additional data to support the development of relevant scenarios on building level should be provided if relevant in the product LCA study, even if the use stage modules are not assessed at the product level. |
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B-17 Operational energy demand for new buildings – Boundaries and scenarios for screening LCA
| Aspect | B-17 Operational energy demand for new buildings – Boundaries and scenarios for screening LCA | |||||
| 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). How can this aspect can be addressed in screening LCA of new 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 screening LCA of new buildings, building-related uses should be accounted for. Other uses may be included according to the object of the assessment. For screening LCA, simplified approaches for calculation or estimation of the operational energy use may be used. | |||||
| Rules from: |
EN 15978:7.4.4.7 Boundaries for operational energy use
8.6.5 Scenarios for operational energy use – Module B6 |
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| Guidance |
For screening LCA, building-related uses defined according to the Energy Performance of Buildings Directive (2002/91/EC) should be accounted for, possibly by the use of simplified calculation methods or estimates, as specific, detailed energy performance calculations may not be available in the early design stages of a building.The expected performance target for the building may be used to estimate the operational building energy demand. The performance may correspond either to energy label targets or to reference levels set by a national regulation. Energy demand should at least be calculated for building-related uses covered by the EPBD directive (heating, cooling and air conditioning, ventilation, domestic hot water, lightning and auxiliary energy used for pumps, control and automation).The breakdown of the energy demand for each energy carrier may be derived from the energy target according to the expected integrated systems (boiler, ventilation, lighting and cooling systems etc.).
Other energy uses may be included and calculated with the help of conventional or statistical data. Link between energy consumption values and environmental impacts Once the energy consumption values are calculated, they need to be associated with generic or specific LCA data for the corresponding process. For example, the number of kWh of electricity in a French building project should be associated with the generic LCA data representing the average mix for the French context. Other energy sources such as fuel, natural gas, wood and district heating also need a generic LCA data describing only the combustion. To this purpose, the infrastructure (e.g. the boilers) should be accounted for as technical equipment. This equipment contributes to the embodied impacts of a building along with the building products. |
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B-18 Operational energy demand for new buildings – Boundaries and scenarios for simplified LCA
| Aspect | B-18 Operational energy demand for new buildings – Boundaries and scenarios for simplified LCA | |||||
| Description |
Several parameters can influence the results of the operational energy demand for the use stage of buildings, such as the selection of uses (i.e. building-related or non-building-related uses). European standards (EN 15804/EN 15978) recommend taking account of priority building-related uses such as heating and cooling. However, non-building-related appliances can significantly influence the energy needs of building-related uses (e.g. the thermal gain of appliances decrease the level of heating demand). How can this aspect can be addressed for in simplified LCA of new 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 simplified LCA of new buildings, every building-integrated system should be accounted for (including building-related uses as described in the EPBD and other building-integrated systems). Non-building-related systems may be also accounted for, considering a conventional or statistical scenario. | |||||
| Rules from: |
EN 15978: 7.4.4.7 Boundaries for operational energy use 8.6.5 Scenarios for operational energy use – Module B6 |
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| Guidance |
Building-related uses are defined according to the Energy Performance of Buildings Directive (2002/91/EC). Energy demand for building-related uses (heating, cooling and air conditioning, ventilation, heating for provision of domestic hot water, lightning) should be calculated either according to national calculation tools and methodology or with the help of thermal dynamic simulation. For comparative assertions the ‘EPA-NR’ calculation tool and methodology can also be used in order to calculate the energy demand on a consistent basis.Building-integrated systems refer to any energy-consuming system required to achieve the expected building functions. They include internal transport (e.g. lifts, escalators), shutters, fire security devices, communication systems, etc.. The energy demand of building-integrated systems may be calculated according to statistical or conventional scenarios.Non-building-related uses include other energy uses such as plug-in appliances (e.g. computers, washing machines, refrigerators, audio, TV) and production- or process-related energy in the use of the building.Scenarios for the calculation of the energy consumption of building-integrated systems and non-building-related uses may reflect statistical or conventional user behaviour. For example, the type and number of appliances and the frequency of use should be calculated according to statistical data if no accurate data are available. The expected performances of user appliances may be taken into account within the calculation, if available (e.g. the consumption of a refrigerator may be estimated according to its certified efficiency).
When no information is available for non-building-related uses, the ratio of consumption provided in EN 15603:2008 (Annex C) may be used. Link between energy consumption values and environmental impacts Once the energy consumption values are calculated, they need to be associated with generic or specific LCA data for the corresponding process. For example, the number of kWh of electricity in a French building project should be associated with the generic LCA data representing the average mix for the French context. Other energy sources such as fuel, natural gas, wood and district heating also need a generic LCA data describing only the combustion. To this purpose, the infrastructure (e.g. the boilers) should be accounted for as technical equipment. This equipment contributes to the embodied impacts of a building along with the building products. Depending on the goal definition of the study (cf. aspect ‘Classifying the decision context between situation A from B from C’), it is possible to choose, e.g. for the electricity consumption, an average mix or a marginal mix. The marginal effects are usually modelled using consequential modelling (situation B according to the ILCD Handbook). A final option is to choose hourly LCA data, particularly in the case where the thermal simulation results are provided on an hourly basis. This remark is part of the EeBGuide aspect ‘Dynamic LCA data for assessing the impact of electricity consumption’). |
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B-19 Operational energy demand for new buildings – Boundaries and scenarios for complete LCA
| Aspect | B-19 Operational energy demand for new buildings – Boundaries and scenarios for complete LCA | |||||
| Description |
Several parameters can influence the results of the operational energy demand for the use stage of buildings, such as the selection of uses (i.e. building-related or non-building-related uses). European standards (EN 15804/EN 15978) recommend taking account of priority building-related uses such as heating and cooling. However, non-building-related appliances can significantly influence the energy needs of building-related uses (e.g. the thermal gain of appliances decrease the level of heating demand). How can this aspect can be addressed for in complete LCA of new 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 complete LCA of a new building, every building-integrated system should be accounted for (including building-related uses considered in the EPBD and other building-integrated systems). Non-building-related systems may be also accounted for. For complete LCA of new buildings, every energy use occurring in the building may be included. Scenarios and data for calculation of the energy demand for each energy use should be specific to the object 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 |
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| Guidance |
For complete LCA, building-related uses considered by the Energy Performance of Buildings Directive (2002/91/EC) should be accounted for. Building-related uses (heating, cooling and air conditioning, ventilation, heating for provision of domestic hot water, lightning) should be calculated either according to national calculation methodology or with the help of thermal dynamic simulation.When thermal dynamic simulation is used, hourly consumption data are required to provide precise information on the energy demand, and to enable the calculation of exported energy in the case of on-site production (see aspect ‘Operational energy calculation – Allocation of on-site energy production’, Module 6)Scenarios for calculation of the energy consumption of building-integrated systems and non-building-related uses may reflect statistical or conventional user behaviour. For example, the type and number of appliances and the frequency of use should be calculated according to statistical data if no accurate data are available. The expected performances of user appliances may be taken into account within the calculation if available (e.g. the consumption of a refrigerator may be estimated according to its certified efficiency). For electricity uses the quantification of impacts should take seasonal and daily variation of the electrical mix into account. When available, hourly data should be used first. If they are not available, monthly average data should be used, or annual average data as a last resort.Link between energy consumption values and environmental impacts
Once the energy consumption values have been calculated, they need to be associated with a specific LCA data, e.g. based on industry data if available; otherwise choose generic data of the corresponding process. For example, the number of kWh of electricity in a French building project should be associated with the generic LCA data representing the average mix for the French context. Other energy sources such as fuel, natural gas, wood and district heating also need a generic LCA data describing only the combustion. To this purpose, the infrastructure (e.g. the boilers) should be accounted for as technical equipment. This equipment contributes to the embodied impacts of a building along with the building products. Depending on the goal definition of the study (cf. aspect ‘Classifying the decision context between situation A from B from C’), it is possible to choose, e.g. for the electricity consumption, an average mix or a marginal mix. The marginal effects are usually modelled using consequential modelling (situation B according to the ILCD Handbook). A final option is to choose hourly LCA data, particularly in the case where the thermal simulation results are provided on an hourly basis. This remark is part of the EeBGuide aspect ‘Dynamic LCA data for assessing the impact of electricity consumption’). |
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B-20 Operational energy demand for existing buildings – Boundaries and scenarios
| 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 |
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| 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-21 Operational energy demand for new buildings – Consideration of user behaviour
| Aspect | B-21 Operational energy demand for new 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 new 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 stand-alone LCA, scenarios may reflect statistical, conventional or specific user behaviour.For comparative assertions, behaviour scenarios for the calculation of energy use should be identical for each alternative. Any deviation between scenarios should be reported and justified. | |||||
| Rules from: |
EN 15978: 8.6.5 Scenarios for operational energy use – Module B6 |
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| Guidance |
For stand-alone LCA, sensitivity analysis should be carried out in order to estimate the significance of the use of a specific scenario instead of a conventional one. | |||||
B-22 Operational energy demand for existing buildings – Consideration of user behaviour
| 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:
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. |
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B-23 Operational energy calculation – Allocation of energy production for on-site systems connected to grid”
| 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).
The method for allocating environmental impact for product aspects and operational aspects should be consistent with the guidance in EN 15978. |
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| 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 |
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| 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:
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:
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’. |
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