Frequently Asked Questions
Q: What baseline materials can I find in the tool especially when doing a LCA in the early design phase?
A: RICS has specified a list of baseline materials that can used in the early design phase. The complete list can be found as Table 16: Default specifications for main buildings, from pages 73 to 76 of the guidance.
In the tool, we have included these datapoints. You can find these by using using the search parameter "RICS Baseline".
You can also use an additional search parameter to specify the type of resource, by using the "+" operator, as shown below.
Q: How do you work the carbon emissions factor for the transportation profiles in One Click LCA, for example, this particular profile Carbon only - HGV (all diesel), All rigids, average laden, accounted for the return trip?
A: All transportation profiles are calculated in line with section 5.1.3 Transport impacts (A4) in the Whole life carbon assessment for the built environment, Professional standard, global, 2nd edition, September 2023.
Please note the following:
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.
Transport impacts should be calculated as follows:
A4 = material or product mass (a) x transport distance (b) x [carbon conversion factor outward (c1) + (empty running factor x carbon conversion factor return (c2))]
Here are two examples of this is worked out as carbon factors for the profiles in the software.
Carbon only - HGV (all diesel), All rigids, average laden, accounted for the return trip
Source: UK Government GHG Conversion Factors for Company Reporting 2023 - Freighting goods
All value declared in kg CO2e | tonkm average | tonkm 100 % | km 100% | km avg | km 0% |
| 0.17819 | 0.12509 | 0.90784 | 0.82313 | 0.65828 |
Then we calculate the full net load:
Km avg / tonkm avg = net average load
0.82313 kg CO2e /km / 0.17819 kg CO2e / tonkm = 4.619395 ton
Finally, we convert the 0% km value to per tonkm value to cover how much is the share of the materials of the empty trip per tonkm:
0.65828 kg CO2e/km / 4.619395 ton x 43% = 0.061276 kg CO2e/tonkm
And this is added to the kg CO2e/tonkm average value
(0.17819 + 0.061276) kg CO2e/tonkm = 0.239467 kg CO2e/tonkm
Carbon only - HGV (all diesel), All HGVs, average laden, accounted for the return trip
Source: UK Government GHG Conversion Factors for Company Reporting 2023 - Freighting goods
All value declared in kg CO2e | tonkm average | tonkm 100 % | km 100% | km avg | km 0% |
| 0,096957 | 0,072150 | 0,98495 | 0,87204 | 0,64257 |
Then we calculate the full net load:
Km avg / tonkm avg = net average load
0,87204 kg CO2e /km / 0,096957 kg CO2e / tonkm
=8.994090 ton
Finally we convert the 0% km value to per tonkm value to cover how much is the share of the materials of the empty trip per tonkm:
0,64257 kg CO2e/km / 8.994090 ton x 43% = 0.030721 kg CO2e/tonkm
And this is added to the kg CO2e/tonkm average value
(0,096957 + 0.030721) kg CO2e/tonkm = 0.127678 kg CO2e/tonkm
Q: How do I correctly input A4 transport distances in One Click LCA to comply with RICS v2?
Overview of RICS v2 A4 Transport Requirements
RICS v2 requires accurate representation of the logistics chain for A4 transport. This includes:
Using actual one-way distances from the plant to the site.
Allowing the A4 formula to handle the return journey through its built-in 0.5 multiplier for the return leg.
Avoiding arbitrary adjustments or percentage reductions to distances.
Correct Methods for Inputting Transport Distances
To comply with RICS v2, follow these steps:
Convert Round-Trip Distances: If your contractor provides round-trip distances, divide the figure by two to calculate the one-way distance. Enter this one-way distance into One Click LCA. The A4 formula will automatically account for the return leg using the 0.5 multiplier on the carbon conversion factor.
Match Vehicle and Load Assumptions: Ensure that the transport vehicle type and average-laden assumptions align with the actual scenario. Load utilization and empty running are already embedded in the emission factors and should not be manually adjusted by distance shares.
Common Mistakes and How to Avoid Them
Avoid these common errors to maintain compliance:
Using Arbitrary Percentage Reductions: RICS v2 does not support arbitrary reductions (e.g., 20–50%) to transport distances. Such adjustments degrade data quality and are non-compliant. Always use actual distances and let the A4 formula handle allocation.
Failing to Justify Estimates: If estimates are used, they must be justified and documented. Replacing real distances with unevidenced percentages is not acceptable under RICS v2.
Importance of Data Quality and Documentation
High-quality data and thorough documentation are critical for compliance. Ensure that all inputs are:
Based on actual measurements or well-supported estimates.
Properly documented to provide transparency and traceability. By following these guidelines, you can ensure that your A4 transport modeling in One Click LCA aligns with RICS v2 standards and maintains the integrity of your data.
Q: Where can I see the top up factors and uncertainty scores in my design?
A: On the results page, after the results summary, you will be able to find this section named "Most contributing materials (Global warming potential - Non-Decarbonised scenario)"
If you scroll further down, you will find this section which shows the top ups and uncertainty scores calculated.
Q: Why is the Module A1-A5 result for Assessment of impacts divided by the GIFA different when I calculate it from the main results?
A. Here are the main results available on the results page. The waste treatment of packaging waste is also included in A5.3. Some materials will have packaging that contains biogenic carbon.
This is currently shown here.
And these are the results on the same page, but showing the impacts divided by the GIFA. For these results the A1-A5 do not include biogenic carbon.
Q: How is biogenic carbon accounted for and reported?
A: There are several mentions of biogenic carbon in the guidelines in sections 2.1, 4.11.1, 4.11.6, 5.2.5, 6.3.5, Appendix K and N.
Figure 2: Building and infrastructure life cycle stages and information modules (adapted from EN 15978, EN 17472 and EN 15643, with additions to illustrate biogenic carbon)
Emissions and removals of all types of carbon (fossil carbon, land use and land use change (LULUC) carbon, and biogenic carbon) are assessed and reported in the modules in which they occur. However, as Figure 2 shows, when reporting upfront carbon (as described below) the sequestered biogenic carbon stored within construction products incorporated into an asset is not included but is reported separately.
The guidelines in section 4.11.1 Biogenic carbon make clear the specifics.
Note: For timber, biobased packaging or timber formwork that is not sustainably sourced, no removal of biogenic carbon must be considered at any point in the life cycle. However, any emission or transfer of sequestered carbon from timber that has not been sustainably sourced must be considered as an emission of carbon arising from land use and land use change (LULUC), considered in the same way as a fossil carbon emission.
If correctly assessed – accounting correctly for all the co-products, waste and combustion of biomass during the production of sustainably sourced timber and other biomass – the sequestered biogenic carbon contained in products and their packaging should be reported as a removal of biogenic CO2 in A1–A3 (i.e. a negative emission of CO2), as an emission of biogenic CO2 for any packaging disposed of in A5, and as an emission of biogenic CO2 in C3 or C4 for the product at end of life. Sustainably sourced biobased product wastage in A5, and any replacement of sustainably sourced biobased products or packaging in B2–B4, will have balanced removals and emissions of biogenic carbon in each module unless methane is emitted during disposal.
Because there should be a biogenic carbon balance over modules A–C, it makes little difference whether biogenic carbon is included in targets for embodied and whole-life carbon, as the removals of biogenic carbon in modules A1–A3 are balanced by emissions in modules C3 and C4.
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.
Biogenic carbon and LULUC carbon must be included with fossil carbon in the calculation of both embodied carbon and WLC.
For timber or other biobased materials (biogenic carbon) that is modelled as reused or recycled at the end of life, the biogenic carbon sequestered within it should be taken into account as a transfer (emission) from C3.
For any net output of biomass into module D, the transferred biogenic carbon should be treated as a removal (a negative emission). Any biogenic carbon sequestered in the substituted product or material in D1 should also be considered in D1. Deducting the impact of the substituted product involves deducting the removal of sequestered carbon in the substituted product, so it will be equivalent to adding it as an emission in D1. If the quantity of sequestered carbon in the recovered and substitute products are the same, this will result in a biogenic carbon balance.
Q: Why are the subtotals in the RICS v2.0 - XLSX results report different from what I have manually added up?
A: The guidelines in section 6.1.4 Accuracy of reporting states the following:
The carbon impacts reported must reflect the accuracy of the calculation, which will depend on the project phases at which the assessor is reporting.
• Early design phase: at building or asset level, calculations and totals should be reported to two significant figures (e.g. 230 kgCO2e/m2 or 1200 kgCO2e/m2 rather than 234.3kgCO2e/m2 or 1234.4 kgCO2e/m2).
• Technical design/construction/post-completion phase: at building or asset level, calculations and totals should be reported to three significant figures (e.g. 234 kgCO2e/m2 or 1230 kgCO2e/m2 rather than 234.3 kgCO2e/m2 or 1234.4 kgCO2e/m2).
Depending on what you have set as the phase of the project of reporting, the subtotals will reflect what the guidelines have stated.
Q: What are the differences between the Reporting Template - buildings and Reporting Template - summary?
A: The main difference between the Reporting template - buildings and the Reporting template - summary is their purpose and level of detail. The buildings template is a detailed data sheet for calculation, while the summary template is a high-level, consolidated report.
Here’s a breakdown of their differences:
Reporting Template - Buildings
Purpose: This template is the primary data entry point for a project's detailed Whole Life Carbon (WLC) calculation. It is a working document for the assessor.
Level of Detail: It is highly granular and requires you to input data for each lifecycle stage from A to D. This includes:
Upfront Carbon (A1-A5): Detailed breakdown of emissions from materials and construction.
Use Stage (B1-B7): Data for operational energy, water, maintenance, repair, and replacement.
End-of-Life (C1-C4): Emissions from deconstruction, transport, and waste processing.
Benefits Beyond the Boundary (D): Benefits from recycling and reuse.
Key Function: This template is where the WLCA uncertainty factor is applied to the upfront carbon (A1-A5). All calculations and adjustments are performed here.
Reporting Template - Summary
Purpose: This template is designed to provide a single-page overview of the final WLCA results for clients and stakeholders. It is a presentation document, not a calculation tool.
Level of Detail: It presents a consolidated view of the data from the buildings and/or infrastructure templates. It doesn't contain the granular, material-by-material data.
Key Function: The template's primary function is to consolidate the final numbers from the detailed templates, normalize the results to a per-square-meter basis, and present the project's total carbon footprint in a clear, easy-to-read format.
Q: Which set of carbon factors are used for B6 calculations?
A: The guidelines in Appendix H (H1 Emissions associated with energy usage) states the following:
Energy usage in buildings is responsible for different types of carbon emissions:
direct emissions associated with energy generation (scope 2), distribution (T&D/scope 3) and use (scope 1, e.g. combustion)
indirect emissions associated with energy generation and distribution (WTT/scope 3), and
indirect emissions associated with the embodied carbon of the infrastructure needed to generate, distribute and store the energy (scope 3).
It is important to understand the whole energy supply chain when choosing a carbon conversion factor for B6 calculations. For a WLCA over the RSP, carbon conversion factors must include all emissions listed above.
The datapoint for input in B6 is taken from set 1 for design decision-making.
The Energy-supplementary tables for Set 1: Whole-life carbon design decision making, gives the following values.
Direct emissions (Scope 2) | WTT emissions (indirect) | Direct (T&D) | WTT emissions (indirect) | Where do you account for it in WLC assessment? | Formula/value | Where do you account for it in WLC assessment? | Formula/value |
#kWh/yr x 60 x 0.2071 kg CO2e/kWh | #kWh/yr x 60 x 0.0459 kg CO2e/kWh | #kWh/yr x 60 x 0.0179 kg CO2e/kWh | #kWh/yr x 60 x 0.0040 kg CO2e/kWh | B6 | #kWh/yr x 60 x 0.020* kg CO2e/kWh | B6 | #kWh/yr x 60 x 0.0004** kg CO2e/kWh |
Adding up the carbon factors (0.2071 + 0.0459 + 0.0179 + 0.0040 + 0.020 + 0.0004), gives 0.2953 kgCO2e/kWh
The data point currently in the tool reflects this as rounded up to 0.3 kgCO2e/kWh.
If you look at the detailed calculations, you will find that it is reflected as 0.2953 kg CO2e/kWh.
For the decarbonised B6 calculation, there is no straightforward breakdown of the emission factor that can be offered, unlike the non-decarbonised emission factor (single factor applied across all 60 years).
Here are the specific RICS 2nd edition references:
This is taken from"RICS 2nd edition, Energy – supplementary tables, 'Carbon conversion sets – UK', row B. Decarbonisation scenario, Electricity:
Highlighted are those that pertain to a building.
Here is how RICS expects us to calculate the decarbonised B6.
RICS 2nd edition, Appendix G4: "Energy decarbonisation factor = decarbonised carbon factor over a RSP of 60 years for direct emissions / current carbon factor for direct emissions … 1 Average decarbonisation factor for FES falling short scenario: 0.0413 kgCO2e/kWh; 2 2023 electricity carbon factor from UK Government GHG Conversion Factors (excluding T&D and WTT): 0.2071 kgCO2e/kWh; 3 Energy decarbonisation factor = 0.0413/0.2071 = 0.2 over 60 years … An embodied carbon decarbonisation factor must also be applied to the embodied carbon of energy infrastructure; the same assumptions are used as in section 4.11.5 (i.e. a factor of 0.5)."
In summary, every year for 60 years, we will be calculating the decarbonised factor, to obtain 60 such differentiated factors, compute the average, before applying this to the energy consumption inputs in the design, to obtain the B6 decarbonised result.
Q: How do I fill in the existing GLA templates with the new RICS v2.0 results report?
A: The existing GLA templates are aligned to the previous RICS v1.0 guidelines. It is expected that GLA will issue new guidance to align with the new RICS v2.0 guidelines. This is the current advisory from GLA with regards to GLA submissions:
The RICS WLC methodology's second edition came into effect on 1 July 2024. The GLA WLC guidance document (including benchmarks) and template are underpinned by first edition methodology, so referable applications should provide assessment in accordance with this guidance. Applicants can additionally provide assessments in accordance with second edition methodology if they wish. Revisions relating to second edition methodology are being considered as we look to update GLA guidance in future.
Please see the full RICS 2nd Edition guidance for more details.