Mat 03 - Responsible sourcing of materials

Bamboo, cork and other non-timber forest products – Responsible sourcing - KBCN1768

Non-timber forest products, such as bamboo and cork should be responsibly sourced to minimise the environmental impacts and protect local ecosystems. However, as they are not timber or timber-based products, these fall outside the scope of the Prerequisite. Where such products are integrated into a building, they should, nonetheless, be assessed and included in the calculator under ‘Other materials’.

Design stage requirements where specific product details are unknown - KBCN1483

The Mat 03 tool must be completed in accordance with the Methodology, providing all available details and submitted as evidence. Where products or materials are subject to a performance specification and a specific manufacturer and certificate reference cannot be provided, the missing details should be completed as 'tbc'. This ensures that a strategy for compliance can be demonstrated, even where some specific details are unavailable.

Erratum – 2018 to V6 – scope – external doors - KBCN1651

The scope of this issue includes external doors. Currently, external doors are missing from the Mat 03 scope 'internal finishes'.

This will be corrected in future versions.

Evidence requirements – responsible sourcing of materials at post-construction - KBCN1599

Whilst the UK BREEAM manuals are less prescriptive in the evidential requirements to allow flexibility, to ensure consistency across the schemes, it is expected that robust evidence should be provided to verify the source of any certified materials and how the assessor has confirmed the products and manufacturers used. Evidence supplied at post construction stage must reflect the completed building and confirm the responsibly sourced materials that have been procured and installed on the project. Supporting documentation is required to validate letters of confirmation or schedules of materials. Evidence provided could include proof of purchase, for example, invoices, delivery tickets, purchase orders or correspondence from suppliers. This may be an example for each material sourced, rather than every delivery ticket for instance. Alternatively, evidence of the use of the responsibly sourced materials may include as-built drawings, O&M documentation or site photographs.

30-Oct-2025 - Applicable to HQM V6 and UKNCR V6.1

FSC and PEFC Mixed Sources certified timber - KBCN00091

Products labelled:

FSC Mix or
PEFC Mixed Sources

Meet the BREEAM responsible sourcing requirements. This means any such products:

In HQM, and in BREEAM NC 2016 or older schemes: meet the prerequisite for legally harvested and traded timber.
In BREEAM NC 2018 or newer schemes: meet the prerequisite for legal and sustainable timber.
In all schemes: can be used to demonstrate responsible sourcing.

Products carrying the FSC Mix label contain at least 70% FSC certified and recycled material. These products may contain a small proportion of FSC Controlled Wood (KBCN00054). However for BREEAM compliance, the FSC Mix label is sufficient to meet our requirements.

30-Oct-2025 - Applicable to HQM V6 and UKNCR V6.1
14-Mar-2024 - Wording clarified and expanded. Relevant prerequisites and requirements clarified. Scheme applicability updated.

FSC Controlled Wood - KBCN00054

The FSC Controlled Wood label minimises the risk that wood comes from illegal or controversial sources, however it does not eliminate this risk. Therefore, products which are:

Labelled as FSC Controlled Wood or,
Where the majority of material in a product is comprised of FSC Controlled Wood,

Do not meet the BREEAM definition of responsibly sourced. Where FSC Mix labelled products contain FSC Controlled Wood, see KBCN00091. This means that any such products:

In HQM, and in BREEAM NC 2016 or older schemes: do not meet the prerequisite for legally harvested and traded timber.
In BREEAM NC 2018 or newer schemes: do not meet the prerequisite for legal and sustainable timber.
In all schemes: cannot be used to demonstrate responsible sourcing.

30-Oct-2025 - Applicable to HQM V6 and UKNCR V6.1
14-Mar-2024 - Wording clarified and expanded. Relevant prerequisites and requirements clarified. Scheme applicability updated.

GN18 BREEAM Recognised Responsible Sourcing Certification Schemes and BREEAM Scheme Applicability - KBCN0723

Latest version: v3.7, May 2023 BREEAM awards credits for responsibly sourcing construction products (typically under the Mat 03 issue) to encourage responsible product specification and procurement in construction. To achieve these credits, applicable specified products (as listed in the relevant technical manual) must be covered by an Environmental Management System (EMS) or a responsible sourcing certification scheme (RSCS) recognised by BREEAM. Guidance Note 18 lists the responsible sourcing certifications schemes recognised by BREEAM along with the relevant summary scores to be used in BREEAM assessments. Download Guidance Note 18 Download Guidance Note 18 v2.0 (licensed assessors only - optional for projects registered prior to release of v3.0 in September 2016) View all Guidance Notes on BREEAM Projects (licensed assessors only)

30-Oct-2025 - Applicable to HQM V6 and UKNCR V6.1

GN24 Demonstrating compliance with Responsible Sourcing requirements in BREEAM - KBCN0721

Latest version: v1.1, May 2022 Guidance Note 24 provides additional guidance to assessors and specifiers on demonstrating compliance with the criteria set out in Mat 03. It should be read in conjunction with the Technical Manual for the relevant assessment scheme. It covers:

How to deal with constituent products/materials including those with certification that is different from the overall product.
The precision required in estimating quantities:
- For the cut-off volume
- Of products/materials in the building (route 2 only)
- Of different material categories in products/materials.
An example route 2 calculation.
‘Broken chain’ situations.
How to treat building services.

Download Guidance Note 24 (licensed assessors only) View all Guidance Notes (licensed assessors only)

30-Oct-2025 - Title updated. Applicable to HQM V6 and UKNCR V6.1

Legally harvested and traded timber – Examples - KBCN0956

The following examples are considered compliant for BREEAM: Legally harvested:

Evidence of compliance with the UK government Timber Procurement Policy (see here, timber bought inside the UK only)
FSC, PEFC, SFI or GiB certification
Evidence of compliance with the EUTR (timber bought inside the EU only)
Risk assessment/due diligence documentation demonstrating a low risk of non-compliance with the ‘legally harvested’ requirements given in the manual.

Legally traded:

Evidence of compliance with the UK government Timber Procurement Policy (see here, timber bought inside the UK only)
FSC, PEFC, SFI or GiB certification
Risk assessment/due diligence documentation demonstrating a low risk of non-compliance with the ‘legally traded’ requirements given in the manual.

04-Dec-2025 - Examples updated to include Grown in Britain (GiB) certification. Previous reference to 'CPET' clarified as 'UK government Timber Procurement Policy'.
KBCN applied more widely to all relevant scheme issues in BREEAM and HQM

Legally harvested and traded/Legal and sustainable timber – Reclaimed/recycled timber - KBCN0654

Timber should, wherever possible, be sourced in accordance with the UK Government’s Timber Procurement Policy. However, if for reclaimed timber the original procurement details are unobtainable, robust evidence to demonstrate it has been reclaimed can be acceptable. The government UK Government Timber Procurement Policy Timber Procurement Advice Note (6th edition) states: As an alternative to demanding timber and wood-derived products from a Legal and Sustainable source, Contracting Authorities can demand ‘recycled timber’. Documentary evidence and independent verification will also apply to recycled timber and recycled wood-derived products but will focus on the use to which the timber was previously put rather than the forest source. And defines ‘recycled timber’ as: “…recovered wood that prior to being supplied to the Contracting Authority had an end use as a standalone object or as part of a structure and which has completed its lifecycle and would otherwise be disposed of as waste. The term ‘recycled’ is used to cover the following categories: pre-consumer recycled wood and wood fibre or industrial by products but excluding sawmill co-products (sawmill co-products are deemed to fall within the category of virgin timber), post-consumer recycled wood and wood fibre, and drift wood. It also covers reclaimed timber which was abandoned or confiscated at least ten years previously.” As per the above policy, BREEAM requires “Documentary evidence and independent verification” that all reclaimed/recycled timber products meet the definition of ‘recycled timber’ given above.

01/06/2020: Amended to clarify and extended applicability to Mat 03

Meeting the minimum standard requirement – compliance when chain of custody is broken - KBCN1816

Where there is a broken chain in the last link between the purchase and delivery of certified timber from the supplier and the forwarding distribution of the timber to the site under assessment, such as where the timber has been delivered to a subcontractor or fabricator’s premises instead of direct to site (e.g. as part of a bulk order or where limited storage is available on site), compliance can still be achieved if a documented risk assessment confirms that there is low risk of mixing or substitution of certified and non-certified timber. Ways to demonstrate compliance: A. Verification that the subcontractor or fabricator only purchases and uses certified timber. There must be robust mechanisms in place to verify that all timber materials purchased and delivered originate from sustainably managed sources. This includes maintaining documented timber procurement policies and procedures that mandate certified timber orders and delivery checks. Comprehensive supplier details should be readily accessible for review upon request to demonstrate that all timber is certified. B. Where non-certified timber is handled/stored or sourced, that there are robust control measures in place to prevent any substitution or mixing of certified and non-certified timber at every stage of the process. Documentation demonstrating compliance should be maintained and made available upon request. Examples of appropriate control measures are listed below:

Control	Evidence required
Purchasing records	All purchase orders, requisition notes, and contracts must explicitly specify the product details and confirm that materials are to originate from legal and sustainable sources.
Segregated storage of timber	Site layout map, stock control processes and records to confirm that certified timber is stored away from non-certified timber.
Segregated delivery of timber to site	- All timber must be thoroughly inspected and verified before shipment to confirm that it is correctly marked/labelled as FSC/PEFC-certified. - Delivery notes must be accurately maintained. - A second-party verification process to check tickets and stock, must be carried out upon site delivery to confirm certified status of timber.
Documentation	Comprehensive documentation must enable independent assessors to trace any timber back to its sustainable source. This includes maintaining purchase records, goods-inward notices, stock records, and sales documentation such as orders and invoices.

The above is guidance and should not replace any local or national requirements for the sourcing of legally traded and harvested timber.

On site fabrication - KBCN1292

Where concrete (or another construction product) is produced on site, there is no requirement to provide responsible sourcing certification for the end product. As in this case fabrication on site is effectively part of the onsite building process, the certification of the individual products (e.g. aggregates, cement), as delivered to site, shall be used in the assessment instead.

Responsible Sourcing – Scope when a BREEAM assessment covers only part of the new building - KBCN1217

To give reliable results, the assessment of responsible sourcing must capture the interactions that occur across an entire design (the system). A design decision in one part of the design will, in many cases, cause knock-on effects to other parts of the design. If only part of a building being designed is included in the assessment the designer may choose a design option that optimises responsible sourcing performance for the limited part analysed, but will be unaware of potential detrimental effects to the overall responsible sourcing performance of the building. In addition, if a responsible sourcing assessment only includes the construction products that form the BREEAM assessment area, inconsistencies arise with regards to construction products that serve all areas of the building in common. For example, an assessment on a central floor that excludes the roof, compared with an assessment on the (otherwise identical) top floor that does include the roof. This approach would be unfair. Therefore, notwithstanding the exception below for internal finishes, the responsible sourcing scope must include the whole building design (as defined in Mat 03, 'Scope of assessment') even if the area covered by BREEAM assessment is only part of the design. The exception to this is any construction products classified as '3. Internal finishes'. Internal finishes are specific to each part of the building with little or no functional relationship with other parts. Therefore, the scope of the assessment of internal finishes shall be limited to the assessed area only.

08 October 2025-made applicable to HQM and UK NCR

Responsible sourcing certification – validity - KBCN1693

Where it can be demonstrated that the responsible sourcing certificates were valid either at the time of specification, or at the time of purchase, they may contribute to the awarding of the credits. BREEAM is primarily trying to encourage designers to take responsible sourcing into consideration when specifying or selecting products and as such it is not necessary for certification to be valid at the time of design or post-construction stage submissions.

30-Oct-2025 - Applicable to HQM V6 and UKNCR V6.1

Responsible Sourcing – Evidence requirements for two (or more) BREEAM assessments on different parts of the same new building - KBCN1218

As the responsible sourcing assessment work must cover the whole new building design (see KBCN1217 'Measuring Responsible Sourcing - Scope when a BREEAM Assessment covers only part of the new building design'), it is equally applicable to all BREEAM assessments being carried out on the building, with the exception of internal finishes. If the assessment scope does not include any construction products classified as '3. Internal finishes', the same responsible sourcing assessment evidence may be submitted for each BREEAM assessment. If the assessment scope does include construction products classified as '3. Internal finishes', then the responsible sourcing assessment evidence submitted must be unique to each BREEAM assessment.

Responsibly sourced timber – government licence - KBCN1033

A government licence, e.g. a UK Forestry Commission felling licence certificate, can be used as evidence of legally sourced timber. It does not meet the definition of a third party timber certification scheme so cannot demonstrate compliance with the responsible sourcing requirements of this Issue.

RSCS summary score level for BES 6001 products - KBCN0955

For products certified under BES 6001, the rating score (between 5 and 7) can be found in the Green Book Live. This is the rating that needs to be entered in the Mat 03 calculator. The RSCS score that is entered into the Mat 03 calculator comes from the relevant table in Guidance Note 18. However, for BES 6001, the score is per certificate because 6001 works at different levels of rigour. Once you have found the product, by searching on the page below, click 'More..' on the right-hand side to reveal further details, including the BREEAM score level. GreenBookLive Responsible Sourcing

Setting of Responsible Sourcing Certification Scores (RSCS) - KBCN00017

Mat 03 credits require the majority of the materials used to be sourced with a high RSCS score. While maximum points (10) are available for reused materials the points available for RSCS's are typically less than 10. The available points are representative of the relative merits of each source while also providing some incentive for each scheme to improve and gain higher scores in the future. The latest points scores for each RSCS route are available in the latest version of GN18.

Sustainable procurement plan – timing - KBCN1659

Where a sustainable procurement plan is not in place before Concept Design (as required in the criteria), the credit can still be achieved if:

A sustainable procurement plan is in place prior to the specification documents being developed.
The assessor justifies that the later timing has not compromised the ability of the plan to guide specification and procurement activities.

07 March 2025 - Reference to end of Concept Design removed in lieu of prior to specification documents being developed, to allow more flexibility on D&B projects.  Full justification will be required where this is to be applied.

New Construction / UK / 2018 / 06 Materials /