Domestic Refurbishment / 2014 /

05 - Materials

Information correct as of 5thDecember 2020. Please see for the latest compliance information.

All insulation material have a Green Guide rating of A or A+ - KBCN1326

Where all insulation material within the building elements external walls, ground floor, roof and building services has a Green Guide rating of A or A+ the Mat 03 Calculator would not need to be completed as the insulation index would always be 2 or greater. Evidence would still be required as follows: In this instance it would not be necessary to provide the volumes and thermal conductivities of each insulation type; however, you must be satisfied that all relevant insulation has been accounted for within the assessed building.

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 this issue. The external walls below ground (i.e. within a basement area) perform a specialist function, these are not comparable with other walls in a building.These are therefore excluded from assessment under this 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 elements’ Materials - KBCN0190

For each element, only the materials that make up a significant majority of the building element (up to 80%) need to be responsibly sourced. Any material which comprise the remaining 20% can be included at the discretion of the assessor if it contributes to achieving more points. It should be noted that including additional elements from a lower tier level may reduce the number of points scored. Criterion 2.b To achieve points for any given building elements, at least 80% of the materials that make-up that element must be responsibly sourced i.e. classified in tier 1-7.

Design stage evidence – Responsible sourcing of construction products assessment - KBCN0831

At design stage, a letter of commitment from the design team confirming that the products shall be procured from suppliers capable of supplying products covered by the required responsible sourcing certification scheme is acceptable. The letter must confirm the responsible sourcing certification schemes of the proposed products.

FSC and PEFC Mixed Sources certified timber - KBCN00091

Products used in a building element that carry these labels are deemed to comply with BREEAM, i.e. 100% of the product (material) is responsibly sourced and 100% contributes toward meeting the BREEAM requirement that at least 80% of an element is responsible sourced. Products carrying the FSC Mixed Sources label have to demonstrate to FSC that the proportion of FSC certified and recycled material used in their production is at least 70%.

FSC Controlled Wood - KBCN00054

FSC Controlled Wood is a system developed to ensure that the non-certified portion in products labelled as Mixed Sources do not come from unwanted sources. It is not an FSC certification on its own and products classed as FSC Controlled Wood do not meet the BREEAM definition of responsibly sourced.  

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

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 Environmental Management System (EMS) or a responsible sourcing certification scheme (RSCS) recognised by BREEAM. View V3.0 of full guidance note View V2.0 of full guidance note (optional for projects registered prior to release of V3.0) View all Guidance Notes (licensed assessors only)

GN24 Demonstrating Compliance with BREEAM Issue Mat 03 - KBCN0721

The purpose of this Guidance Note is to provide 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. The following is covered: — Definition of terms used — 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 View full Guidance Note (licensed assessors only) View all Guidance Notes (licensed assessors only)

Green Guide ratings for domestic buildings of more than four storeys high - KBCN1106

For domestic projects of greater than 4 storeys it is advised to use the domestic ratings for the first four storeys and commercial ratings for the higher storeys. If the designed structure of the first four storeys are more similar to commercial than domestic due to the load of a higher structure, you may use the commercial ratings for the whole building. This approach ensures the most appropriate ratings are used based on the characteristics of the building. 

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.

Location of the Refurbishment Green Guide Calculator? - KBCN0288

The Refurbishment Green Guide Calculator is within the generic Green Guide Calculator on the BRE Website. When adding a new specification please select 'Refurbishment - Domestic' as the name of the scheme. This will allow you to specify 'reused' elements which can have a green guide rating up to A+(6)  

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'

Raised access floors - KBCN00018

For the purposes of Mat 03, raised access floors should be considered as part of the floor structure. HQM - Applies to HQM's Responsible Sourcing of Construction Products assessment issue.

Scope of ‘Building services’ location/use category - KBCN000001

'Building services' refers to the equipment and distribution systems specified for providing heating, power, ventilation, lighting, air-conditioning and domestic water services in a building. As a minimum, this location/use category should include the equipment and controls specified for the building services. Refer to Guidance Note GN24: Demonstrating Compliance with BREEAM Issue Mat 03 issue for more information.
18/10/2018  Applicability to UK NC2018 removed; relevant guidance is included in the technical manual.

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.  

U-values - KBCN0191

U-Values should be based on the data shown in section 3 of the SAP assessment, or in the case of RdSAP should be provided from your Domestic Energy Assessor.  
Information correct as of 5thDecember 2020. Please see for the latest compliance information.