Mat 03 - Responsible sourcing of construction products

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’.

Definition – Reused in situ - KBCN1902

Definition A material qualifies as reused in situ where it meets all of the following:

It is removed from its original position or original application within the building.
It undergoes no more than minor processing that does not alter its fundamental nature (e.g. cleaning, cutting, fixing to other materials).
It is reinstalled in a different position or a different application within the building (or reused elsewhere within the project).

Exclusion Materials that remain in their original location and application throughout the works, including where they undergo minor processing such as cleaning, repair or redecoration, are considered as retained. These must be excluded from the Mat 03 calculator.

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

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 (GN18) 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)

21-Jul-2026 - Applicable to NC V6, NC V7, RFO V7

GN24 Demonstrating compliance with responsible sourcing requirements in BREEAM - KBCN0721

Latest version: v1.2, July 2026 Guidance Note 24 (GN24) provides additional guidance to assessors and specifiers on demonstrating compliance with the 'Measuring responsible sourcing' criteria in BREEAM (typically 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 View all Guidance Notes on BREEAM Projects (licensed assessors only)

15-Jul-2026 - Updated version released (v1.2)

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

New Construction / UK / V7 / 06 - Materials /