The Royal Institute of Chartered Surveyors (RICS) published the 2nd edition of the Whole Life Carbon Assessment for the Built Environment, Professional Standard (WLCA PS) in September 2023. This standard, which aligns very closely with the European standards EN 15978, EN17472, EN15643 & EN15804 provides comprehensive guidance for teams assessing whole life carbon emissions for construction projects and Built environment assets. Effective from 1 July 2024, it serves as the framework for the Built Environment Carbon Database (BECD) and is mandatory for RICS members.
The WLCA PS 2nd edition introduces significant expansions and updates compared to the previous 2017 RICS guidance. Key areas with notable changes include:
- Reporting Modules
- Element Categorisation for Buildings and Infrastructure
- Defined Parameters and Emissions Factors
- Transport Impact Calculations
- Biogenic Carbon
- Uncertainty Analysis
- Decarbonisation
- Multiple end of life scenarios
eTool has adhered to the previous 2017 RICS version, and the software has now been updated to support users in meeting the requirements of both the 2017 and 2nd edition standards. We’ve gone beyond the mandatory requirements by adding numerous features to eTool, enabling users to model their LCAs in accordance with RICS guidance.
For guidance on using eTool in line with the new RICS WLCA 2nd Edition, please refer to the support post below:
Please be aware that the BRE IMPACT dataset (used for BREEAM and other BRE-managed certifications) and the eTool Default dataset (aligned with EN15978) — along with their associated templates — are separate and cannot be used interchangeably.
The RICS guideline is specifically integrated into eTool for projects using the eTool Default dataset.
Below is a summary of the mandatory requirements from the new standard and details on how eTool ensures adherence.
| Section | Requirement | ETOOL Compliance | Notes and Guidance Using eTool |
|---|---|---|---|
| 3.1 | For new-build assets, either buildings or infrastructure assets/civil engineering works, all life cycle stages must be assessed, including module D (which is reported separately). All building or infrastructure elements within the project site boundary (red line or equivalent) must be included in the WLCA. | Yes | Set by users during project setup (modules) & structure set up (construction scope) |
| 3.2 |
When any full or partial demolition or deconstruction of an existing structure is required, to facilitate the construction of a new asset within the designated site boundary or as an extension to the existing asset, the impacts associated with that demolition or deconstruction must be included in the WLCA in sub-module A5.1 |
Yes |
New sub-module available in RICS WLCA 2E (2023) calculation standard. User can set up the impact allocation for Pre-construction demolition (module A5.1) at the element level. A range of equipment can be selected in eTool to model demolition activities. |
| 3.2 |
Where a project is initiated on a brownfield site, emissions from any demolition that has already occurred via a previous site owner or event must still be considered within the scope of the WLCA and be reported in A5.1, if demolition occurs within three years of the sale or new proposal. |
Yes |
New sub-module available in RICS WLCA 2E (2023) calculation standard. User can set up the impact allocation for Pre-construction demolition (module A5.1) at the element level. A range of equipment can be selected in eTool to model demolition activities. |
| 3.3 |
All retrofit/refurbishment projects should be treated as new projects and must report against all life cycle stages over the defined reference study period (RSP). |
Yes | Set by users during project setup |
| 3.3 |
Any demolition/deconstruction or alterations to facilitate the retrofit/refurbishment works, including removals and/or stripping out of elements, must be treated as pre-construction works and reported in the separate sub-module A5.1. New material added to the asset or project will result in product and construction stage impacts, which must be reported in modules A1–A5. New material may also cause in-use stage impacts, such as for maintenance or replacement, which must be reported in module B. End-of-life impacts from new material must be reported in module C, and potential post-end-of-life benefits or loads outside the system boundary must be reported separately in module D However, retained elements may result in impacts during the in-use stage, such as from maintenance or replacement, which must be reported in module B; from their end-of life impacts, which must be reported in module C; and from potential benefits or loads outside the system boundary from their recovery, which must be reported in module D |
Yes | eTool reports impacts separately for each module A0-A5 (Construction phase), B1-B8 (Use phase), C1-C4 (End of life phase) & D1-D2 (Benefits and Loads Beyond the System Boundary). |
| 3.3 |
Whole life carbon reporting for a retrofit/refurbishment project must recognise the average carbon impacts across the total project gross internal area (GIA), as well as the constituent parts. |
Yes | Functional unit set by user at Design level |
| 3.4 |
Where a planned change of use is considered, two assessments must be undertaken – one with and one without the planned change of use – in order to facilitate benchmarking. |
Partial |
The requirement for Module B5 (as interpreted by RICS) is quite rare. There are however options for users, please reach out to eTool for assistance should this be required. |
| 3.5 | The scope of external works impacts reported must include all excavations and site preparations required to facilitate the new assets. All life cycle stages and module D (separately) must be reported, as it is assumed that the asset owner will be responsible for the WLC impacts of those elements, including the in-use and end-of-life stages. | Yes | Set by users during project setup (modules) & structure set up (construction scope) |
| 4.1 | A complete WLCA undertaken in compliance with this standard must account for carbon removals and emissions arising over the entire life cycle of a built asset (modules A–C). It must also separately account for the loads and benefits beyond the system boundary considered in module D. |
Yes | Set by users during project setup (modules) |
| 4.2 | Reference Study Periods | Yes | Configurable by users when creating or editing design. |
| 4.4.1 | All building elements set out in the Building element categories document that are within the scope of a building project, or within the scope of an infrastructure project that includes buildings, and all associated construction works must be included in any compliant WLCA, whatever the project phase. |
Yes | Configurable by user at Structure level. New Element Categorisation RICS WLCA 2E (2023) for Building available. |
| 4.4.2 | All element categories set out in Appendix C that are within the scope of an infrastructure project or a building project that includes infrastructure must be included in any compliant WLCA, whatever the project phase. |
Yes | Configurable by user at Structure level. New Element Categorisation ICMS3 for Infrastructure available. |
| 4.5 | A compliant WLCA must cover all items listed in the project’s bill of quantities (BoQ), cost plan and quantity take-offs (QTOs), or as identified in other records (3D/BIM models, drawings, specifications, etc.). Material quantities from the sources listed in Table 6 must be used for each phase, and their source clearly stated in the WLCA. | Yes | eTool allows users to import BIM information, BoQ or cost plan information, or estimations from consultant’s drawings. |
| 4.5.3 | For existing assets on site that are retained, their ongoing maintenance, repair and replacement over the life of the asset must be reported in modules B1–B4, their impact at the end of life in C1–C4, and any potential benefits and loads from their recovery at end of life in D1. |
Yes |
eTool allows detailed accounting of existing assets maintenance, repair and replacement activities to be allocated in modules B1-B4, EoL impacts on C1-C4 and, any potential benefits and loads from their recovery at end of life in D1. For more information on on modelling retention of existing items, please click on the following link: Modeling Existing Buildings for Adaptive-Reuse in eTool |
| 4.5.4 | The demolition, waste processing and transport of any material from the demolition/ deconstruction of the existing asset that is required to facilitate new works, or as part of a retrofit/refurbishment, must be reported in sub-module A5.1. |
Yes | New sub-module available in RICS WLCA 2E (2023) calculation standard. User can set up the impact allocation for Pre-construction demolition (module A5.1) at the element level. |
| 4.7 |
The WLC assessor must explicitly state the data source in the WLCA report, and for generic data the territorial scope and basis (consumption- or production-based) for the various types of carbon data used in the WLCA. |
Yes |
eTool automatically references the users’ data sources in the reports (both background data and EPDs if used). Data quality compliance is also automatically reported which covers both the background data and user entries in the software |
| 4.9 | A non-decarbonised and a decarbonised scenario must always be calculated. |
Yes |
Decarbonised grids are available for modelling in eTool. |
| 4.9 |
The carbon conversion factors used (for energy use) must account for both direct and indirect GHG emissions: scopes 1, 2 and 3, including well-to-tank (WTT) and transmission and distribution (T&D) impacts, and should account for the embodied carbon of energy infrastructure where applicable and available. |
Yes | eTool utility grids account for scopes 1, 2, and 3 emissions and include WTT and T&D impacts. These can be separated in the reports or using the in-built analysis tool. |
| 4.10.1 |
To account for uncertainty in this standard, the WLC assessor must consider contingency for the project based on the uncertainty at the time of the assessment. In order to account for uncertainty and lack of detailed or complete information, particularly during the early design phases, after assessing and reporting the results for each life cycle information module and element category using Reporting template – buildings or Reporting template – infrastructure, the relevant contingency factor(s) must be applied to all modules A–D before reporting upfront, embodied, operational and user carbon in Reporting template – summary. The contingency factor(s) used must be reported in the WLCA report. |
Yes | Set by users during project setup and at the design level. The uncertainty results can be found in the All Impact Details report. For more information on how to set up the uncertainty factors in eTool, please click on the following link: Uncertainty Analysis. |
| 4.10.2 |
During the detailed design, construction and post-completion phases, the asset carbon confidence score produced using this method must be reported in the WLCA report, together with the percentage of the asset’s overall upfront and embodied carbon for which the key products are responsible. In order to account for uncertainty regarding the representativeness of carbon data and its quality, after assessing and reporting the results of each life cycle information module and element category using Reporting template – buildings or Reporting template – infrastructure, the carbon data uncertainty factor must be applied to all modules A–D before reporting upfront, embodied, operational and user carbon using Reporting template – summary. |
Yes | Same as section 4.10.1 |
| 4.10.3 |
During the detailed design, construction and post-completion phases, the quantities uncertainty factor must be assessed using the approach set out in this section, and this assessment must be included in the WLCA report. In order to account for uncertainty regarding the quantities data, after assessing and reporting results for each life cycle information module and element category using Reporting template – buildings or Reporting template – infrastructure, the quantities uncertainty factor must be applied to all modules A–D before reporting upfront, embodied, operational and user carbon using Reporting template – summary. |
Yes | Same as section 4.10.1 |
| 4.11.1 |
When any biomass (e.g. timber or agricultural crops) enters the technosphere, any sequestered carbon – the biogenic carbon contained or ‘sequestered’ within the biomass – must be considered as a removal of biogenic CO2 from nature into the product system in the module in which it enters the system, but only, in the case of timber, if it has been sustainably sourced. To be compliant with this standard, biogenic carbon must be reported as described in the reporting templates. Section 6 details the reporting requirements. |
Yes |
The eTool calculation engine now facilitates different treatments of biogenic carbon through the calculation standard – selected at the project level. The ‘RICS WLCA 2E (2023)’ and ‘EN15978 (EN15804+A2)’ calculation standards both treat biogenic carbon from sustainably sourced materials as 100% released/transferred to nature at end of life, and biogenic carbon from non-sustainably sourced materials is treated as LULUC carbon (no sequestration, emissions only). |
| 4.11 |
The sequestered biogenic carbon in sustainably sourced timber and other biomass must be considered to leave the product system boundary when it is either:
In each case, this must be considered as an emission of biogenic carbon (as CO2 or methane as appropriate) in the module in which it leaves the system. |
Yes | Same as above |
| 4.11.1 |
Biogenic carbon removals and emissions from modules A1–A3 (the sequestered biogenic carbon within products) must not be included in the calculation of upfront carbon, but must be reported separately as the sequestered biogenic carbon stored within the asset in A1–A3. Any LULUC carbon emissions in A1–A5 must be considered as a fossil carbon emission, and included with other fossil carbon emissions and removals in A1–A5 in the calculation of upfront carbon. Biogenic carbon and LULUC carbon must be included with fossil carbon in the calculation of both embodied carbon and WLC. Biogenic carbon and LULUC carbon must not be decarbonised. |
Yes |
eTool reports GWP-F, GWP-B, and GWP-LULUC separately and by module. eTool data v20 and later are compliant with EN 15804+A2 for biogenic carbon |
| 4.11.2 |
Carbonation rates depend on the duration of exposure, concrete designation and exposure conditions, including any concrete surface treatments which will most likely limit carbonation. |
Yes | eTool facilitates modelling of various carbonation scenarios in module B1. |
| 4.11.3 |
Embodied carbon and operational energy can be assessed separately. However, when they are brought together to optimise whole life carbon, predictive energy modelling must be carried out, as described in section 5.3 relating to module B6. |
Yes | eTool allow user to enter own data from predictive energy modelling reports. Additionally, a number of electricity and energy sources may be selected for accounting for B6 impacts. |
| 4.11.4 |
For future energy projections, results both with and without grid decarbonisation must always be reported, clearly stating the grid decarbonisation source used |
Yes | Configurable by user at project level. eTool developed the new ‘RICS decarbonised’ grids (including the gas grid). To visit our recommendations in how to model both designs, please click on the following link: Decarbonisation |
| 4.11.5 |
Results both with and without material decarbonisation, according to Table 15, must always be reported |
Yes | eTool RICS automated report presents results with and without material decarbonisation. |
| 4.11.6 |
Carbon offsets, temporary carbon storage and permanent biogenic carbon storage (for example in landfill or carbon capture and storage) are not to be considered in the calculation of the GWP impact in EPD according to EN 15804+A2. |
Yes |
eTool WLC calculations are aligned with EN15804+A2 and exclude carbon offsets, temporary carbon storage and permanent biogenic carbon. |
| 5.1.2 |
Product stage (A1–A3): The carbon impacts attributable to the product stage of the items included in the WLCA must be calculated by assigning suitable embodied carbon factors to the elemental material quantities. |
Yes | eTool includes a comprehensive database of construction products. Users are provided a range of methods of calculating quantities and defining baseline specifications. |
| 5.1.2 | To ensure baseline consistency, for UK assets the following assumptions must be used in early design phase WLCAs that are to act as baselines for progressive reporting. (See Table 16 below) | Yes |
Concrete strengths and replacement contents can be chosen in eTool to match the building specification. Recycled Content can be specified for steel in all models utilising the eTool Default LCI Sources Users can configure the strength and density of concrete (to simulate different concrete block work) A wide variety of timber options are available for selection in eTool Aluminium recycled content can be specified in all models utilising the eTool Default LCI Sources Users may enter EPD data to for Plasterboard with 60% recycled content (or utilise eTool LCI data for specific plasterboard specs of buildings) Users may enter EPD data for PIR based insulation (or utilise eTool LCI data for specific insulation specs of buildings) Recycled Content can be specified for aggregates in all models utilising the eTool Default LCI Sources A wide variety of glass options are available for selection in eTool A wide variety of plastics options are available for selection in eTool Users may enter EPD data for specific coatings product (or utilise eTool LCI data for specific coating specs of buildings) Binder Content can be specified for Asphalt in all models utilising the eTool Default LCI Sources Bitumen options are available for selection in eTool Users may enter EPD data for specific MEP product (or utilise eTool LCI data for specific MEP specs of buildings) A wide variety of Facade options are available for selection in eTool |
| 5.1.3 | Transport impacts (A4): Transport impacts must include all stages of the journey of the products following their departure from the final manufacturing plant to the project site, including return journeys, taking into account any interim stops at storage depots and/or distribution centres. | Yes | Users may enter as many transport legs as they wish. eTool default transport distances usually have at least two legs (apart from locally manufactured products) Additionally, return journey can be added while project set up or at the details tab at design level. |
| 5.1.4 |
Construction – installation process (A5): The carbon impacts arising from any on-site construction-related activities must be considered in module A5. Including sub-modules:
|
Yes | eTool allows the quantification of pre-construction demolition accounted in sub-module A5.1; a detailed construction processes including the energy use of equipment and plant reported in sub-module A5.2. eTool accounts for wastes generated during construction in sub-module A5.3. The waste percentage is configurable along with the disposal method and recycling rate of the material. And the transport of construction workers accounted in sub-module A5.4 |
| 5.1.4 | For all schemes, any carbon impacts resulting from the deconstruction/demolition, transporting and disposal of waste as part of the main works must be accounted for in A5.1, which should be reported separately.
|
Yes | Same as section 3.2 |
| 5.2 | In-use Stage: The in-use stage must capture the carbon impacts associated with the operation of the built asset over its entire life cycle, from project completion to the end of the RSP. | Yes | eTool allows detailed inputs of maintenance, repair, replacement, refurbishment and operational energy and water use (and treatment) over the life cycle of the building. |
|
5.2.1 |
In-use impacts (B1): B.1.1: Material emissions and removals B1.2 Fugitive emissions (refrigerants) Any non-energy-related carbon removals or emissions arising from components during the life of the built asset must be reported in B1 Annual refrigerant leakage from MEP equipment must be accounted for, as detailed in CIBSE TM65. |
Yes |
Sub-modules B1.1 (In-use material emissions and removals) & B1.2 (In-use fugitive emissions (refrigerants)) are available for reporting in eTool RICS automated report when selecting the RICS WLCA 2E (2023)‘ calculation standard at project level. Note: Refrigerant leakage configurable by user at element level |
| 5.2.2 |
Maintenance impacts (B2): must account for the carbon impacts from any activities relating to maintenance processes, including cleaning, as well as any relevant products used and waste produced over the RSP. |
Yes | eTool allows detailed accounting of maintenance and cleaning activities. |
| 5.2.3 |
Repair impacts (B3): must take into account carbon impacts from all activities that relate to repair processes, and any products used and waste produced over the RSP. All impacts from the production, transportation to and from site, and installation of the repaired items must be included. |
Yes | eTool allows detailed accounting of repair activities. |
| 5.2.4 |
Replacement emissions (B4): For the purposes of consistency, a WLCA must assume the like-for-like replacement of products, components and systems as required over the RSP. These replacements must be reported in B4. Module B4 must take into account any carbon impacts associated with the anticipated replacement of built asset components, including any impacts from the replacement process, over the RSP. All impacts from the production, transportation to site and installation of the replacement items must be included, as well as any losses during these processes, as well as any impacts associated with the removal and end-of-life treatment of replaced items. For both buildings and infrastructure, the repair and replacement impacts must be considered using the same data for materials and products as was used in modules A1–A5 for installation and modules C and D for their end of life. Note: Module B4 should be split and reported as two separate sub-modules: B4.1 (Replacement of construction products, components and systems) & B4.2 (Replacement of industrial systems (if applicable for infrastructure)). |
Yes |
eTool allows reporting of replacement activities in Modules B4 (Default LCI Sources). Note: optional sub-modules not included in reporting. But could probably be reported by user in a custom excel template by sorting B4 impacts by construction category.
|
| 5.2.5 |
Refurbishment emissions: All impacts arising from the production, transport to site and installation of the components used for a change or refurbishment planned prior to project completion, but undertaken during the in-use stage, must be included in B5. Adjustments must also be made to all modules B, C and D in the WLCA from the point of change, in order to accommodate the impact of the altered asset. The consideration of biogenic carbon in B5 must be treated in the same way as for a new project, but note that any net addition or removal of sequestered biogenic carbon from the asset during B5 must be reported separately in the appropriate |
Partial | The requirement for Module B5 is quite rare. There are, however, options for users, please reach out to eTool for assistance should this be required. |
| 5.3 |
Operational energy use (B6): This subsection covers carbon emissions from all operational energy use by a building or infrastructure asset over its life cycle, which must be reported in B6. Operational emissions include all asset-related operational energy use: regulated (B6.1) and unregulated (B6.2 and B6.3), as described in EN15978-1 Annual energy consumption in kWh or equivalent must be converted to carbon using the appropriate carbon conversion factor sets. For buildings, operational impacts must include all operational energy used in the building, including heating, hot water, cooling, ventilation, lighting, cooking, equipment and lifts, broken down separately by fuel type and energy end use. |
Yes | A number of electricity and energy sources may be selected to account for B6 impacts. Reporting categories can be updated by the user if required. |
| 5.3.1 |
The scope must include end uses in Table 21. |
Yes | End use operational energy categories available in eTool. |
| 5.3.6 | Energy from renewables: energy from onsite renewables and the electricity grid must be reported separately | Yes | A number of electricity and energy sources may be selected for accounting for B6 impacts. |
| 5.4 |
Operational water use (B7): All carbon impacts related to water supply and wastewater treatment, as measured and/ or predicted over the life cycle of the asset (excluding water use during maintenance, repair, replacement and refurbishment that are reported elsewhere), must be reported under module B7. Where relevant, B7 should cover the following:
|
Yes |
If using the default eTool LCI Sources both water use and treatment can be accurately quantified in eTool. Sub-modules available for reporting in eTool in the All Impacts Report when selecting the RICS WLCA 2E (2023)‘ calculation standard at project level. Configurable by user when entering operational water data. |
| 5.6 | End of life stage (C1–C4): Module C impacts must be included for all components and materials that make up an asset at the end of the RSP, whether the asset continues to provide functionality or not. Any impacts arising from decommissioning, stripping out, disassembly, deconstruction and demolition operations, as well as from transport, waste processing and disposal of materials at the end of life of the project, must also be accounted for in module C. |
Yes | eTool allows the detailed quantification of all end of life scenarios. Recovery rates are also configurable. |
| 5.6.1 | End of life scenarios (recommendation): The end-of-life scenarios must be clearly stated and explained in the WLCA report. The proportions allocated in the WLCA at the design, construction and post-completion stages to various reuse, recycling, other recovery or disposal end-of-life routes for different materials and components must be supported by verifiable and project-specific documentation if they vary from the ‘business as usual’ (BAU) end-of-life routes set out in Table 22 for the UK. |
Yes |
End of life scenarios and recovery rate are fully configurable for users. For more information on how to set up muti EoL in eTool, please click on the following link: New Multi End-of-Life Disposal Methods |
| 5.6.2 | Deconstruction and demolition impacts (C1): The impacts arising from any on- or offsite deconstruction and demolition activities at the end of life of the asset, including any energy consumption for site accommodation and plant use, must be considered in C1. Where there are building or infrastructure elements such as foundations, pipes, cables or ducts within 3m of ground level, the removal and disposal of these items must be accounted for, even if their removal is not anticipated within or at the end of life of the assessed asset. If the asset includes underground voids, tunnels or basement structures more than 3m below ground that would not be practically anticipated to be removed, then any stabilisation works required to make them safe must be accounted for in C1, for example by filling belowground tanks with an inert compacted material. |
Yes | A range of equipment can be selected in eTool to model end of life demolition activities. |
| 5.6.3 | Transport impacts (C2): Any carbon impacts associated with the transportation of material from deconstruction and demolition to the appropriate final location, including any interim stations, must be captured in module C2. |
Yes | Included and configurable by users. |
| 5.6.4 | Waste processing for reuse, recycling or other recovery (C3): When materials and/or components are intended to be reused, recycled or recovered after the RSP of the asset, any impacts associated with their preparation for reuse, waste treatment and recovery prior to reaching the end-of-waste state must be included in module C3. |
Yes | In most cases the end of waste state for commonly recycled construction products is met before the product leaves site (eg scarp aluminium, steel etc) has a market value as soon as it is separated on site. However in cases where processing is required to achieve value such as recycling of brick and tile waste for road-base, the disposal method will include impacts in Module C3. |
| 5.6.5 | Disposal emissions (C4): For elements not expected to be reused, recycled or recovered, but intended for final disposal either in landfill or incineration, an allowance for the impacts from their disposal must be included in C4. |
Yes | For most products a range of disposal methods may be selected to accurately model the disposal emissions. |
|
5.7 |
Benefits and loads beyond the system boundary (D1 and D2): Module D is reported as two separate sub-modules:
|
Yes |
eTool accounts for module D benefits and loads in the following sub-modules:
|
| 6 | Reporting requirements | Yes |
Users can enter all of the mandatory information into eTool using the designated fields or the description fields at the Project, Structure, and Design levels. The RICS reporting templates can be populated from the All Impact details report automatically generated in eTool. |
