HS2 LCA modelling and reporting

HS2 LCA modelling and reporting



Revised by

Date reviewed

Reason for reviewing


Henrique Mendonça

2.   Fei Ngeow 15/05/2023 Information needed updating

Introduction and Background

This guidance will be updated periodically so please check back each time you are conducting LCA modelling and reporting to HS2, submitting rating scheme documentation or starting a new project.

This article is complementary to HS2 guidance and supporting documentation, with a focus on eTool use. The goal is to increase consistency across different HS2 contractors and ensure eTool users are aligned with HS2 LCA modelling and reporting process.

HS2 eTool Stakeholder Communications List

This mailing list is managed by Cerclos to communicate any HS2 reporting guidance updates with their stakeholders.

If you are currently working on the HS2 project and would like to be part of this group email please sign up HERE to receive HS2 reporting guidance updates.

Jump to the following sections in this post:

HS2 Supporting documentation

Please contact HS2 to request access to the most updated documentation.

LCA Tool Guidance P02

Appendix 2 Step by Step

Bulk Upload Data – Material by Asset Number (to be provided by HS2)

Additional supporting documentation:


Software Supports

Technical standard – Carbon Footprinting & Life Cycle Assessment (HS2-HS2-SU-STD-000-000010)

This technical standard sets out the specification for conducting LCA to minimise whole life cycle carbon emissions, reduce embedded environmental impacts and improve the materials efficiency metric.

Technical Standard – Sustainable Sourcing (HS2-HS2-SU-STD-000-000012)

This technical standard sets out the requirements of the project Sustainable Sourcing Plan, which requires LCA and MEM data from the tool.

Guidance Note –Sustainable Materials Guidance Phase One (HS2-HS2-SU-NOT-000-000005)

A guidance note that highlights all the interlinking requirements for sustainable materials.

Sustainable Materials Guidance Note Phase 2a (HS2-HS2-SU-NOT-000-000007)

Sustainable Materials Guidance Note Phase 2b (HS2-HS2-SU-NOT-000-000008)


Jump back to contents ↑

HS2 LCA Study Goals

In accordance with the climate change objective of the HS2 Sustainability Policy, a carbon management strategy will be developed and applied and will:

  • calculate the carbon footprint of the Proposed Scheme and use this as a tool to assess the potential to reduce carbon across the design, construction and operation phase;
  • consider low carbon options in developing the detailed design of the Proposed Scheme;
  • reduce embodied carbon in construction materials and carbon emissions from construction works, where practicable;
  • reduce energy requirements of the scheme and maximise the energy efficiency of operations, if practicable;
  • use and/or generate low carbon energy, if practicable; and
  • sequester carbon, if practicable. (source)

Jump back to contents ↑

HS2 carbon reduction requirements

The HS2 Ltd Sustainability Policy 4 states the aim to “minimise the carbon footprint of HS2 as far as practicable and deliver low carbon long distance journeys that are supported by low carbon energy”. 


Greenhouse gas emissions not regulated by the EU ETS, predominantly from construction, will be managed through other policy tools as part of the Climate Change Act target of at least an 80% reduction in emissions by 2050. Nevertheless HS2 Ltd is committed to minimising carbon emissions both in the traded and non-traded sectors by implementation of its Sustainability Policy.

HS2 has also set ambitious targets for our supply chain to minimise the whole life carbon emissions of our assets including buildings. For stations this includes achieving net zero carbon in operation for regulated emissions and achieving a 50% reduction in whole life carbon emissions against a baseline for a typical station. Source

By setting a 50% carbon reduction target on construction baselines for Phase One civil assets (such as tunnels, viaducts and cuttings), stations and railway system, we can empower and challenge HS2 Ltd and our supply chain to innovate to reduce carbon.

Jump back to contents ↑

HS2 Project Programme and LCA deliverables

Key benefits

eTool has been approved by HS2 using standard compliant methodology, data sources, modelling and reporting. The whole process is managed inside eTool to increase consistency and transparency across different software users and stakeholders. 

HS2 uses asset-based data input, modelling and reporting. eTool has bulk upload features and can produce results by assets with the multiple functions.

eTool dynamic licensing and collaborative platform allows multiple users to develop LCA projects together including HS2 internal users and external contractors.

Data quality

eTool LCI Source

Latest version as of 17/05/2023: eTool Default v18 (v19 pending release in the near future)

Carbon footprint methodology aligned and approved by HS2: carbon factors adopted, the density and weight of construction material, or transport vehicles assumed for logistics.

Some HS2 contractors are encountering difficulties to re-baseline LCA models and align the data and results with eTool. This is mainly related to models completed in different tools or spreadsheets, different inventory data and different methodologies.

This article explains the benefits of using Life Cycle Inventory database in comparison to EPDs or ICE database. Other variables like waste factor, lost in transport and transport impacts are also included in eTool templates. It is important to ensure the scope is the same when comparing emission factors. 

eTool recommends that HS2 defines together with their contractors the correct association between project components and eTool templates so all users are following the same procedure as a benchmark and results are comparable. eTool hasn´t received any guidance from HS2 on this topic yet so please provide feedback directly to HS2 to help standardise the process.

If you have any questions regarding this please contact HS2 and eTool for technical assistance. It is extremely important that all HS2 contractors are using the same inventory data, EPD and modelling assumptions moving forward.

HS2 Custom Concrete Mixes

The process to create custom concrete mixes needs to be validated with HS2 and aligned with all contractors. It is important all models are produced using the same process and data quality to ensure consistency and alignment to the standards. 

The recommended method to create concrete mixes is to use the current materials available in the inventory instead of adding new custom products using the EPD functionality. Here is a template example with guidance provided in the template details tab. https://etoollcd.com/Library/Template/Index/39104

Once this process is validated and the templates are created, these templates can be submitted for validation with eTool and made public to all users, or kept within the HS2 organisation via the Organisation template ownership functionality. 

System Boundary

All life cycle modules A-D

HS2 to provide more information about the additional life cycle modules related to PAS2080:

  • A0 – Planning and project management
  • B8 – Other operational processes
  • B9 – Users utilization of infrastructure

Custom software development is available for HS2 to capture and report results according to their Carbon Management Plan.


Detailed information about LCA scope to be confirmed by HS2:

  • Different project phases: Phase 1, Phase 2a, Phase 2b
  • Different contracts
  • Innovation location
  • Multiple HS2 functions / assets (see detailed list provided by HS2)
  • Whole project life cycle
    Initial construction impacts
  • Embodied impacts
  • Operational impacts


Specific benchmark models for different asset types and default project specifications to represent business as usual practices are yet to be defined by HS2.

This is really important to set a common reference for all different contractors to compare their performance against a benchmark result and demonstrate the percentage target reduction has been achieved.

Benchmark models include standard asset definition and construction specification that represent current construction practices, for example machinery and equipment use, steel and concrete specifications.

Benchmark models should be available in the HS2 ORG in eTool so every time a new project is created, users can refer to it as a starting point.

Third Party Verification

Ensure templates are validated, designs are certified, users are trained before they produce results and reports using eTool.

eTool haven´t certified any HS2 model yet. eTool highly recommends certifying the models before exporting results or generating reports.

This is part of our services scope at no extra cost to HS2, and provides specific project support to ensure model completeness and quality.


Automated reports are available in eTool. The goal is to avoid manipulation of data externally or custom reports that are hard to be audited.

HS2 are currently defining specific reporting requirements beyond the existing reports available in eTool. Once this is confirmed eTool will provide custom software development to create HS2 specific reports, automatically produced by eTool.

HS2 should also provide an example report showing the required content and results format:

  • Asset (function) 
  • Whole contract 
  • Project specific phases
  • Other reporting requirements

HS2 will create an example report with graphical elements with consolidated results and main information only. The goal is to have an automated report with the final results that can be used at different stages (baseline, review, design review, construction, as built). After this example is created eTool will quote to develop the automated report within eTool.

In the meantime, contractors are exporting data using the all impacts report and creating their own custom reports which makes it very hard for HS2 to audit and validate.


Details to be provided by HS2


Details to be provided by HS2


Details to be provided by HS2

Hitting Carbon Reduction Targets

HS2 and HS2 contractors to provide more details about project specification and improvement strategies that will be used to achieve the reduction target.

Materials Efficiency Metrics

HS2 is measuring circularity using eTool unique Materials Efficiency Metric.

HS2 Time Frames

HS2 to provide more details about reporting periods and what are the deliverables expected by the contractors.

Jump back to contents ↑

HS2 Stakeholder Beginner & Intermediate eTool Software Training

All HS2 stakeholders are required to complete the basic eTool online software training courses before they can start modeling for HS2. Even long time eTool users are strongly encouraged to complete the online training courses if they haven’t already. Not only is it a good refresher to cover new features in the software since any initial training, course completion records will be linked to stakeholders’ eTool profile which will form part of their profile identity in the eTool Community. This will affect how the software performs for all eTool users in terms of whether they can submit a design for certification (user needs to hold a valid subscription and completed the training courses).

The courses are free to all eTool users. Once you’ve fully registered your account, click on the ‘Help’ link on the top right corner of the eTool page to access the support site at any time.

When you’re at the support site, just click on the eTool training icon to enroll in the course.

There are two sets of training – Buildings or Infrastructure. Each set will contain both ‘Beginner’ & ‘Intermediate’ training courses. HS2 stakeholders should complete the ‘Infrastructure’ set of training courses prior to modeling to get up to speed with the foundational understanding of how eTool works.

For further HS2 specific training for eTool modeling, please refer to the rest of this post or one of your HS2 Organisation Admins.

Jump back to contents ↑

HS2 Project setup in eTool

As per the technical standards and the HS2 Asset Information Management System (AIMS) HS2 contractor is required to report asset level Life Cycle Assessments. 

HS2 LCA models are created using multiple functions (assets) that are aligned with AIMS and BIM models. AIMS set the asset (function) numbers. The goal is to have a unique asset ID and facilitate a multi-disciplinary team to work with the same reference during different stages of the project.

At the moment, eTool users are utilising the material element level instead of a component system level to upload data in eTool. 

AS per HS2 explanation, eTool templates including equipment and machinery use will be introduced later when the LCA models are developed further. These will likely be separated from materials and specific templates with equipment use so it can be customised and updated during the as-built stage.

Please refer to the Granularity of the Assessment topic for further information and why eTool recommends using the component level template (concrete pump + concrete + steel reinforcement + formwork) instead of the material level template (concrete only). 

eTool recommends that an example project is created in eTool from start to finish to be used as a reference by HS2 contractors. This example will present the hierarchy and how projects need to be set up in eTool. 

Project & User Management Portal

HS2’s organisation portal in eTool allows secure and collaborative work. Any user assigned as an Organisation Admin will have full administrative control over project & user management.

Below are useful links regarding the project/user management side of the software:

Please contact the HS2 organisation admin user in case you need access to specific projects or designs, or add new users to the HS2 portal in eTool.

Import Process – Bulk upload

Contractors are using the most up to date and granular data provided by HS2 within design therefore each component is mapped for specification and quantity.

HS2 LCA lead to load functions first before users can add and match templates, if asset ID is properly defined, the matching algorithm will match templates with the correct assets automatically.

Carbon Leads working on eTool need to ensure that relevant project information that is missing from 3D models are also included in the model to meet the completeness requirements. 

When you upload if you have a column with “Asset ID” the software will match this against Asset IDs (providing the Asset IDs actually match).  


Matching process will be streamlined as the software algorithm learns how eTool templates are associated with HS2 asset information and description. 

HS2 Template Ownership

HS2 users can assign ownership of templates to HS2 Org in eTool. Although eTool encourages clients to validate their templates with eTool and make them public, eTool offers an option to keep templates private in the user account or assign template ownership to Organisations.

Data aggregation

The CSV files are a direct output from BIM meaning as per the Design Carbon Management.

Usually these files contain a lot of duplication and can make the import process slow.  

eTool recommends that software users aggregate the data first to avoid duplication. 

Pivot table the data, as suggested by eTool LCD Coach team. Contact eTool to get a copy of a simple spreadsheet to support this process. Software users can see a little checksum on the right hand side of the pivot table to ensure the Pivot Table is outputting the same volume (in total) as the raw data.

Depending on the file size and number of assets to be imported, eTool recommends splitting up the CSV file into multiple smaller uploads.

Remove blank lines from the csv import file to speed up the process and avoid errors. 

Detailed guidance available on the support article below:


Granularity of asset assignment

  • HS2´s requirement to align with AIMS (asset IDs) as this is the main reference for multiple disciplines that will be working on different assets throughout the project design and construction.
  • Modelling process using current HS2 templates (main materials only) is significantly reducing the quality of LCA models, as well as the scope included in the model.
  • One example is Crewe Tunnel North Portal Auto-transformer Station (Hybrid Bill Update) that was modelled only with material disposal offsite, concrete, steel reinforcement, plastic, temporary formwork, whereas significant impacts from copper, SF6 gas(proxy), aluminium, galvanised steel for example were not included.
  • HS2 to provide more details about the quality of the LCA model and how they are planning to improve / add more to it as the design progresses and different disciplines are working on the same asset during design and construction.
  • HS2 to provide more details about their BIM models to understand how the HS2 templates need to be expanded. 
  • HS2 custom templates to be validated by eTool.

Moving functions within a design

The ability to move structures or functions between projects or designs is not native functionality to eTool at the moment.

Clone a design into a new project: 

  • Main screen at design level > action button > clone.
  • Users can’t transfer specific functions only, you can only clone the whole design with all functions in it, or
  • Create a new design and load new functions again.

Clone the design to an existing structure or project, or create a new structure or project:

  • Users can´t transfer functions from one design to another. 
  • Users can load new functions to an existing design.

Move structures between projects:

  • Users can’t clone structures to a new project. 
  • Users can create a new structure in an existing project and clone a design into this new structure.

Pain Points

This section will be developed further as we gather feedback from software users and align the modelling and reporting requirements with HS2.

Instead of addressing individual users’ pain points, eTool recommends to align with HS2 first and then replicate a standard procedure to all users.

Jump back to contents ↑

eTool Software Licensing

Specialist HotSeat & Specialist External Seat

Please refer to this support post: What is the Difference Between ‘Specialist Hotseat’ and ‘Specialist External Seat’ in eTool?

Support Requests

For all Support requests, please refer to this support post: How Do I Make A Support Request?

When you submit your Support Request through the support site, please ensure that you specify ‘HS2’ under the ‘Category’ field for tracking, quality and training purposes.

Note that if you submit your support request via email, you won’t be able to fill out the fields above and we may not be able to respond to your request according to HS2’s service level agreements.

LCI Source access

In case you are working on HS2 and don’t have access to the latest LCI Source (inventory), please submit a support request for access. This is currently a manual process however we are working on automating this feature in the next software release.


If you are unable to find the information you need, still have questions or would like to provide feedback as an opportunity for improvement, please submit a Support Request and refer to this guidance document.

One Comment

  1. Alan5842

    I’m after some clarity on how water use is treated in relation to the MEM? We are reporting construction water use (and its associated carbon impacts) on eTool now, and it has significantly increased our volumes of renewable materials figure for the MEM compared to previous reports. However the HS2 standard defines renewable materials as “Materials which have been produced by living organisms and sustainably harvested such as timber, bamboo and wool and have been legally and sustainably sourced.”

    I have been unable to find out whether water meets this definition? Might you be able to advise whether it should it not, as its not produced by living oranisms and isn’t harvested sustainably, rather it is pumped or tankered?

    Thank you

Leave A Comment?

You must be logged in to post a comment.