06 - Materials - BREEAM Knowledge Base

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’.

Clarification of ‘Embodied carbon benchmark comparison’ - KBCN1819

The embodied carbon benchmark comparison must always be based on the latest appropriate LCA stage that corresponds to the BREEAM assessment stage being pursued. The purpose of the benchmark comparison is to assess outcome-based embodied carbon performance, using data that is representative of the building at the relevant assessment stage.

Assessment stage requirements

Interim (Design Stage) BREEAM assessments

Where an interim / design stage assessment is being submitted:
- The benchmark comparison may be based on a Technical Design LCA, where this represents the latest LCA available at that stage.
- Benchmark results at this stage are indicative and intended to support design decision-making.

Final Post-Construction Stage (PCS) BREEAM assessments

Where a final post-construction stage (PCS) assessment is being submitted:
- Benchmark comparison credits can only be awarded where a Post-Construction Stage (PCS) LCA has been completed.
- A technical design LCA alone is not sufficient to support benchmark comparison credits at PCS.
- This is because the PCS LCA is the only assessment that reflects the materials and products actually installed in the completed building, and therefore the only suitable basis for outcome-based benchmarking.

If a PCS LCA is not undertaken, benchmark comparison credits cannot be awarded at final assessment, regardless of whether a technical design LCA was previously completed. This aligns with wider industry frameworks (e.g. RICS WLCA v2 and the UK Net Zero Carbon Buildings Standard), which anchor performance claims to as-built outcomes.

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.

Early design phase LCA submission – Modified planning applications - KBCN1893

Requirement In the Mat 01 Methodology, M1.2 requires the early design phase LCA to be completed and submitted to BREEAM within 20 working days of submission of the planning application. Intent This requirement is in place to ensure that the LCA is carried out during the early design stages and can meaningfully influence material selection and key design decisions, before the planning application fixes significant aspects of the external specification. The timeframe of 20 working days post-planning submission is a concession to allow project teams to collate the LCA evidence for submission to BREEAM. Submission of the planning application In this context, this is the application that specifies and fixes the external products and materials that are considered in the LCA. By default, this is considered as the first application. However, it may also be:

A supplementary modified application, where a staged submission process is used

A replacement modified application, due to a major redesign

Where the requirement is applied to a supplementary or replacement application, the project team must provide additional evidence to demonstrate that the intent is met. Additional evidence

Confirmation of the date of the original planning application and the date of the modified application.

A description of what the modified application changes, with reference to the relevant submission documents.

Evidence that the modification significantly affects external products or materials specification, e.g. revised elevations, façade specification, external material schedules

Justification of how the early design LCA submitted in relation to the modified application was still capable of influencing relevant design decisions

Erratum – UK NC V7 – Mat 01- Table 9.2: LCA Study Periods - KBCN1830

In Table 9.2: LCA quality requirements: Item 9, the study period should be 60 years for all stages, in line with RICS. This is a typographical error in the Technical Manual and will be corrected in the next re-issue.

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)

GN51 Guidance on LCA and embodied carbon calculations for Mat 01 in BREEAM V7 - KBCN1684

Latest version: v1.0, July 2026 Guidance Note 51 (GN51) provides supporting information for the new Mat 01 criteria in BREEAM V7. Its development is driven by the introduction of new credit allocation criteria for Mat 01. While the core principles of measuring and reporting a building's environmental performance through life cycle assessment (LCA) and benchmarking were introduced in BREEAM UK New Construction 2018, significant revisions have been made to align the criteria across BREEAM schemes and with existing LCA frameworks and methodologies. This guidance note explains the primary methodology for Mat 01, including minimum requirements and the scope of the LCA. Download Guidance Note 51 View all Guidance Notes on BREEAM Projects (licensed assessors only)

15-Jul-2026 - Updated version released (v1.0)

Independent third party – clarification on the definition - KBCN1805

For the purposes of BREEAM, sister companies or parent companies cannot be considered as third parties. To be classed as an independent third party, there must be no professional connection or relationship between the LCA consultant/energy assessor, or their company, and the verification body. The third-party verifier must be independent of the LCA or energy assessor and demonstrate impartiality (for general principles, see ISO 17029). To qualify as a third party, the verifier must belong to an organisation not involved in the project and must not provide advice to the project, as this could compromise their impartiality during verification.

LCA Concept Design stage submission before the assessment is registered - KBCN1437

In certain circumstances, it may be necessary for the design team to submit the Concept Design stage LCA before the BREEAM assessment has been registered. In such cases, please submit the LCA tool and associated files along with details of your situation as follows:

Licensed BREEAM assessors should do so using the webform: https://tools.breeam.com/projects/queryadd.jsp
Other interested parties can submit their case to breeam@bregroup.com

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

Life Cycle Assessment – Similar buildings approach (GN20 – Section 4) - KBCN1834

Where multiple buildings are included within the scope of a single BREEAM assessment following the Similar Buildings approach, in accordance with Section 4 of GN20, unless identical, each building must be assessed and reported separately within the LCA. Where all buildings are demonstrably identical in design and specification (and differ only in scale), a representative LCA approach may be used (see KBCN1890). Shared elements (e.g. substructure, external works, or building services serving multiple buildings) may be apportioned between buildings using a reasonable and transparent method (e.g. by gross internal area or other appropriate project-specific metric), in line with recognised industry approaches. For the purposes of BREEAM benchmarking under Mat 01: • The results submitted to the platform must represent a single building, not a combined site-wide result. • Where multiple buildings are included within an assessment, the worst-performing building (in kgCO₂e/m²) must be used for benchmarking in line with the Similar Buildings methodology (section 4.2 of GN20). Full evidence must be provided to demonstrate: • That all buildings within scope of the assessment have been included, with individual LCAs completed for each building, and • How results have been separated and, where relevant, how shared elements have been allocated.

Rationale: In line with Section 4.2 of GN20, BREEAM issues must be assessed for each individual building, with credits awarded based on the worst‑performing building for each assessment issue. The Similar Buildings approach therefore remains an individual‑building assessment methodology and does not constitute a site‑wide assessment, even where multiple buildings are included.

09.07.2026 Reference to KBCN1890 added

Life Cycle Assessment – Similar buildings with identical design (GN20 Section 4) – Representative LCA approach - KBCN1890

Where multiple buildings are substantially identical in design, construction and specification, and any differences are limited to scale, a representative LCA approach may be used instead of completing a full LCA for every building. Where buildings are not substantially identical, see KBCN1834. For the purposes of BREEAM benchmarking under Mat01:

A representative LCA and a single options appraisal may be applied across all buildings, provided that all specifications (including scoped elements) are consistent and carbon reduction measures are specification-driven rather than scale-dependent.
Robust justification and supporting evidence must be provided to confirm representativeness. The representative model should normally be the largest, most carbon-intensive, or otherwise demonstrably representative building within the development.
Results must be expressed in normalised form (e.g. kgCO₂e/m²) and demonstrated to be applicable across all units, with any variation in outcomes shown to be not materially significant (e.g. within ±10%).
Shared elements (e.g. substructure, external works, or building services serving multiple buildings) may be apportioned between buildings using a reasonable and transparent method (e.g. by gross internal area or other appropriate project-specific metric), in line with recognised industry approaches.

Demonstrating representativeness does not require full LCAs for additional units; proportionate methods such as parametric scaling of quantities or elemental intensity comparisons may be used to evidence that variation in normalised results is not materially significant. Where there is uncertainty regarding representativeness, a secondary check model for an additional unit is recommended to verify consistency of results.

Rationale: The representative LCA approach provides a proportionate means of assessing developments containing multiple highly similar buildings while maintaining confidence that reported results are representative of individual building performance. It is intended as a limited exception to the standard requirement for building-specific assessment.

New Construction / UK / V7 /

06 - Materials