New Construction / UK / 2014 / 06-Materials /

Mat 01 – Life Cycle Impacts

Information correct as of 24thMay 2024. Please see kb.breeam.com for the latest compliance information.

Achieving Exemplary level criteria using Route 2 - KBCN0928

The project’s appointed BREEAM assessor needs to submit a copy of the IMPACT file/model to BRE Global. Files/models should be submitted as a technical query entitled as ‘UK NC Mat 01 IMPACT model submission’, together with the completed IMPACT form (found on BREEAM Projects, under the UK New Construction 2014 ‘Supporting documents’) and with evidence demonstrating compliance with criterion 7 (demonstrate how the use of an IMPACT compliant software, or equivalent, has benefited the building in terms of measuring and reducing its environmental impact). Note that for IMPACT queries, we aim to provide the initial file/model review report within 4 weeks. Please allow for additional time for this in the process, as the BREEAM Assessor is likely to receive feedback regarding the file/model content, which will need to be addressed before submitting the BREEAM assessment report for Quality Assurance. When this review process is complete and the file/model is verified and approved by BRE Global, you will receive an approval confirmation for compliance with Route 2, which will allow the relevant exemplary credits to be awarded.

All life cycle stages EPDs - KBCN0822

A third party, independently verified EN 15804 EPD that includes life cycle stages A, B and C may be considered a tier 1 EPD in the MAT 01 issue.

Assessing basement external walls - KBCN0241

Only the external walls above ground level are required to be assessed under 'external walls'. The external walls below ground (i.e. within a basement area) perform a specialist function, these are not comparable with other external walls in a building. These are included in the 'basement retaining walls'.
20/08/2021 Scope clarified in accordance with the New Rules of Measurement (NRM) by the Royal Institute of Chartered Surveyors (RICS).

Assessing the roof of a car park that forms the ground floor of the assessed building - KBCN00080

The ground floor of the building above the car park should be assessed as an 'upper floor slab'. For the purposes of Mat 01 the ground floor slab, which is not assessed, is considered to be the floor which is in contact with the ground. HQM - Applies to HQM's Environmental Impact from Construction Products assessment issue.  

BRE Environmental Profile certificates - KBCN0777

BRE Environmental Profile certificates are compliant EPDs and can be used as evidence for the purposes of Mat 01.

Building LCA tools recognised by BREEAM - KBCN1118

The following document shows the building LCA tools that are recognised by BREEAM for each BREEAM scheme. Only submissions from the tools listed here will be accepted as part of a BREEAM assessment. These recognised tools may be either an IMPACT Compliant tool or another type of building LCA tool that has been evaluated by BREEAM and considered suitable for carrying out building LCA according to BREEAM’s scheme specific requirements. To apply for a new tool to be evaluated, please contact: [email protected] Where more than one version of the same tool is listed for a given scheme version, the most recent version of the tool (that is available at the point building LCA work commences on the project) should be used. It is acceptable to use subsequent, more recent releases/versions of a recognised tool (that have the same name as shown in the table). View Building LCA tools recognised by BREEAM.      
Table updated to new downloadable format, with new layout and new recognised LCA tools and corrections added 01/03/2024
Table updated to include new recognised LCA tools and corrections 10/11/2023
Table updated to include new recognised LCA tools and corrections 22/07/2022
Table updated to include new recognised LCA tools 12/03/2021
KBCN updated for clarity regarding subsequent tool versions on 10/03/2021

Environmental Product Declaration (EPD)- Calculating the percentages of materials - KBCN00070

When calculating the contribution of EPDs to an element's point score in the Mat 01 tool, the percentage of material in an element should be based on its mass.      

EPDs’ validity - KBCN0798

EPDs which have expired or are pending verification at the time the relevant product was specified, cannot contribute to awarding credits. However, it is not necessary that they are valid at the time of the design or post-construction stage submissions. BREEAM is primarily trying to encourage designers to take EPDs into consideration when specifying products.  
04/11/2019 Confirmed applicability to UK NC2018
27/03/2020 Added applicability to Green Guide ratings and ISO 14001 certificates
27/05/2020 Reference to ISO 14001 removed - Whilst the same principle applies, the wording relating to product specification does not - See KBCN1401.
12/08/2021 Clarification regarding the validity of EPDs during QA submission and removal of reference to Green Guide ratings

GN08 – Scope of IMPACT compliant tools and data submission requirements - KBCN0621

Scope of IMPACT Compliant (or equivalent) Tools and Data Submission Requirements - BREEAM UK New Construction 2011 and 2014 Introduction This Guidance Note relates to complying with the exemplary level criteria for route 2, as defined under the Mat01 issue of the BREEAM New Construction 2011 and 2014 versions. It provides information about IMPACT and the level of detail (the Quality Requirements) and file transmission requirements for the Building Information Model (BIM) from IMPACT compliant (or equivalent) tools. It also outlines criteria for demonstrating the equivalence of a proposed alternative to IMPACT compliant tools for BRE Global approval. View full Guidance Note (licenced assessors only) View all Guidance Notes (licenced assessors only)

GN17 Bespoke Green Guide Specifications - KBCN0633

Introduction This Guidance Note provides advice for BREEAM and Code for Sustainable Homes assessors where a Green Guide rating cannot easily be found or matched on the online Green Guide. View full Guidance Note (licensed assessors only) View all Guidance Notes (licensed assessors only)

Green Guide – Updated validity requirements - KBCN1466

It has been recognised that, due to the withdrawal of the Green Guide methodology in the current version of BREEAM UK New Construction, some manufacturers are not updating their product certifications against this environmental profiling scheme. Therefore, where robust evidence can be provided that the composition and properties of such products or materials have not changed since they were certified, the expired Green Guide Rating may be used, where available. This supersedes the guidance previously provided in relation to Green Guide validity in KBCN0798

Green Guide Rating of raised access flooring - KBCN00016

There are currently no Green Guide ratings available for raised access floors, therefore the components making up the raised floor element itself should be excluded from the assessment of this issue.
24 01 18 Wording clarified to refer to raised floor components only

Green Guide ratings for multi-residential - KBCN0788

For multi-residential buildings please use the Green Guide ratings listed under the ’Domestic’ category. Where the Multi-residential building is a high rise building i.e. more than 3 stories high, ratings from the ‘commercial’ category of the Green Guide must be used for the external walls and window elements. To obtain appropriate Green Guide ratings for floor finishes within Multi-residential development, select the ‘healthcare’ category for floor finishes fitted in the communal areas and corridors and ‘domestic’ for those fitted in the over threshold area.

Green-roofs - KBCN0263

When assessing green roofs,  only the structural elements of the roof construction need to be considered i.e. the waterproof layer and above can be excluded. Where Green Guide is being used to assess the issue, it is likely that the online Green Guide Calculator will need to be used to provide a rating for the roof construction. HQM - For the purpose of HQM, green roofs fall under 3.3 Specialist roof systems therefore should be included in the IMPACT model.

IMPACT Compliant (or equivalent) Tools - KBCN0929

The following are IMPACT compliant tools The following are equivalent to IMPACT compliant tools:

IMPACT compliant software - KBCN0809

For a list of all IMPACT compliant software please see How to get IMPACT on the IMPACT website.

LCA modelling for multiple BREEAM assessments - KBCN0960

Multiple buildings' assessments Site-wide approaches are not acceptable and each BREEAM assessment needs to have its own Life Cycle Assessment model (using an IMPACT compliant software tool or equivalent). This applies in all cases, including when the buildings are on the same plot and are built to the same specifications. Developing assessment-specific LCA models ensures that material quantities are accurate, refer to the actual building (and building type) and account for external works included within the scope of the specific assessment. Single building with multiple assessments within it Where multiple assessments are conducted for different parts of a building, it is acceptable to have a single LCA model covering all assessments. In this case, an explanation of the allocation process used should be provided and the following guidance applies:

Life cycle environmental impact of curtain walling - KBCN0178

Curtain walling performs two functions – the provision of windows and the provision of external walls. Specifications performing the same function are grouped together in the Green Guide to Specification.  This means that curtain walling needs to be modelled as two separate building elements (external walls and windows). The overall performance of the curtain wall will combine the ratings for the two parts according to their areas. It will depend on the curtain walling system selected, the choice of internal lining and the relevant proportion of glazed and opaque elements.
  1. For the opaque area of the external wall (Area A in the figure below):
    1. Select the relevant generic specification from the Green Guide (element category – External walls / Curtain walling, then either aluminium or timber framed and the internal skin specification) and note the rating and element number. If your specification is different from all of the generics, please submit a request for a bespoke rating.
    2. Enter the rating into the BREEAM Materials calculator with the area for the opaque section of the curtain wall (Area A).
  2. For the glazed (window-like) area of the curtain wall (Area B):
    1. Select the relevant specification from the Commercial window element category of the Green Guide. There are two specifications: Aluminium curtain walling system (Element no: 831500016) and Laminated timber curtain walling system (Element no: 831500015)
    2. Enter the rating into the BREEAM Materials calculator with the area for the glazed (window-like) section of the curtain wall (Area B).
The BREEAM Materials calculator will calculate the overall performance for the curtain walling system. It will also calculate the performance of the building elements and the overall number of credits to be awarded.      

Louvered panels/facades on Green Guide - KBCN1252

The BRE Green Guide defines the 'functional unit' for applicable materials, which may be assessed under the Mat 01 Issue: Louvres on a facade provide a role outside of the 'functional unit' and hence can be excluded from the calculations for the external wall. Only elements forming part of the 'functional unit' need to be included in the external wall.

Mat 01 / Mat 03 calculator not big enough - KBCN0647

If a project has more specifications than there is rows available in the tool you can group specifications that have the same green guide rating/responsible sourcing level with each of the specifications with the same rating listed in the same row. The proportion that they contribute to the overall area is also combined. For example where a project has 30 different upper floor specifications, if 10 upper floor specifications are A+, 10 are A, 5 are B and 5 are C then you would only need to use 4 lines.

Mat 01 EPD uplift calculation - KBCN1335

The methodology for calculating the EPD uplift requires use of the Responsible Sourcing of Materials search tool, available on the assessor extranet. The Responsible Sourcing of Materials search tool will list the relative mass of each constituent material of a defined element as a percentage. However, due to an error on the system the Responsible Sourcing of Materials search tool is currently referring to volume instead of mass. This error will be resolved shortly. However for clarification in the interim, the EPD uplift calculation is based on mass, as per the methodology within the manual. The Responsible Sourcing of Materials search tool lists the relative mass of each constituent material of a defined element as a percentage, and until the tool is updated the term ‘volume’ should be ignored.

Material not listed in the Green Guide calculator - KBCN0377

Please refer to Guidance Note GN17 'Bespoke Green Guide Specification Guidance' available from the BREEAM Extranet under 'Green Guide to Specification - Assessor information'

The importance of EPDs - KBCN0895

The publishing of a third party verified EPD by a manufacturer indicates a transparent, robust and credible step in the pursuit and achievement of real sustainability in practice. While an EPD in itself is not proof that a product is sustainable, it is a public declaration of the environmental impacts associated with specified life cycle stages of that product.  A manufacturer or group of manufacturers, who carry out life cycle assessment (LCA) studies on their product(s) and publish the results in verified EPDs, help to create a knowledge base and an awareness of the environmental impacts quantified using standardised metrics. This allows benchmarking and the identification of improvement opportunities for the product’s environmental credentials. By implication, there are also opportunities for economic and social benefits to the manufacturer, such as the reduction in resource wastage through improvements in product design and manufacturing efficiency. The reward for EPDs in BREEAM schemes promotes the above, while encouraging designers, procurers and other stakeholders to make decisions on the basis of robust and credible environmental data. This is one of the markers of BRE’s strategic approach to the selection and procurement of construction materials and products. We recognise that there may be steep costs at the moment to small manufacturers wishing to publish verified EPDs for their products. This is a result of the maturity of the market and it is anticipated that as the awareness of the benefits of EPD increases, the increased uptake of EPDs will drive costs down.
Information correct as of 24thMay 2024. Please see kb.breeam.com for the latest compliance information.