|Number of credits available||Minimum standards|
To recognise and encourage the use of thermal insulation which has a low embodied environmental impact relative to its thermal properties and has been responsibly sourced.
This issue is split into three parts;
The following is required to demonstrate compliance for:
For each type of thermal insulation used in the relevant building elements, the volume weighted thermal resistance provided by each type of insulation is calculated as follows:
The volume weighted thermal resistance for each insulation material is then multiplied by the relevant Green Guide point(s) from the following table to give the Green Guide Rating corrected value:
|Green Guide Rating||Points/element|
To calculate the Insulation Index, the sum of the Green Guide rating corrected values for all insulating elements is divided by the sum of the volume weighted thermal resistance values (an example calculation is provided in the Additional Information section).
Note: Where an independently verified third-party Environmental Product Declaration (EPD), covering part of or the whole life cycle, is available for an insulating material/product, this can be used to increase the contribution of that material/product to the building’s Mat 04 performance (for more detail refer to the Calculation procedures in the Additional Information section).
|Material||Key Process||Supply chain processes|
|Foam Insulation||Insulation manufacture||Main polymer production, e.g. Polystyrene, MDI, Phenolic resin or equivalent|
|Stone wool, glass & cellular glass made using < 50% recycled input||Product manufacture||Any quarried or mined mineral over 20% of input|
|Wool||Product manufacture||Wool scouring|
|Products using > 50% recycled content except those using timber||Product manufacture||Recycled content by default|
|Timber-based insulation materials including those using recycled timber||Product manufacture||Recycled timber by default, all other timber from one of the recognised timber certification schemes in BREEAM issue Mat 03.|
|Other renewable-based insulation materials using agricultural by-products (e.g. straw)||Product manufacture||By-product manufacture by default|
|Any other product||Product manufacture||1 or 2 main inputs with significant production or extraction impacts should be identified|
It is envisaged that the majority (80%+) of fabric/services insulation will be specified/installed in the shell and core building. Where the shell only developer is not installing the majority of insulation, compliance with this BREEAM issue for the tenanted areas of the building can be demonstrated via one of the following means:
Refer to Appendix D – BREEAM New Construction and shell and core/speculative assessments of this Scheme Document for further description of the above options.
|Insulation incorporated as part of an off-site manufactured element||If the insulation is incorporated as a component of an element that has been manufactured offsite (in order to maximise material optimisation) e.g. a wall or roof, and that element has been assessed as part of Mat 01, then for the purpose of assessing the insulation for this BREEAM issue, a Green Guide rating of A+ should be used. The same rule applies to insulation that has a significant additional function, such as providing supporting structure e.g. structural insulated panels (SIPS). In the Green Guide the actual insulation will be listed within the element title, rather than under the generic insulation category.|
|Awarding credits||Both credits can be awarded independently of each other - i.e. it is not a requirement of the second credit that the first is achieved, and vice-versa.|
|Element consisting of more than one insulation type See criterion 4||Where more than one insulation type is present for a given element, the rating, area and conductivity for each insulation type should be entered into the BREEAM Mat 04 calculator and an average is calculated (by volume).|
|Finding exact Green Guide Ratings See criterion 2||Where no similar insulation can be found assessors should seek guidance from BRE on the appropriate rating.|
|Environmental Profile Certification of products||Mat 01 Life cycle impacts Compliance Notes.|
Design drawings AND/OR relevant section/clauses of the building specification or contract confirming:
Manufacturer’s technical details confirming the thickness and thermal conductivity of the insulating materials specified.
A copy of the output from the BREEAM Mat 04 calculator.
The Green Guide rating and element number for the assessed insulation specifications.
And if relevant:
'As built' drawings and, where relevant, written design team confirmation of any changes to the materials specification.
|5||Evidence as outlined in BREEAM issue Mat 03 confirming compliance for the insulating materials.||Evidence as outlined in BREEAM issue Mat 03 confirming compliance for the insulating materials.|
The Insulation Index is calculated for a building using the following types of insulation:
Type 1 Walls
Area = 450m2. Thermal insulation thickness = 100mm. Thermal conductivity = 0.023 W/mK Green Guide rating = A (2 points)
Volume weighted thermal resistance: ((450x0.100)/0.023) = 1956
Green Guide rating correction: 1956 x 2.0 = 3912
Type 2 Building Services
Volume of insulation used = 21m3. Thermal conductivity = 0.022 W/mK
Green Guide rating = C (0.5 points)
Volume weighted thermal resistance: (21/0.022) = 955
Green Guide rating correction: 955 x 0.5 = 477
Type 3 Roof
Area = 210m2. Thermal insulation thickness = 120mm. Thermal conductivity = 0.027 W/mK Green Guide rating = A+ (3 points)
Volume weighted thermal resistance: ((210x0.120)/0.027) = 933
Green Guide rating correction: 933 x 3.0 = 2799
Type 4 Ground Floor
Area = 210m2. Thermal insulation thickness = 120mm. Thermal conductivity = 0.027 W/mK Green Guide rating = B (1 point)
Volume weighted thermal resistance: ((210x0.120)/0.027) = 933
Green Guide rating correction: 933 x 1.0 = 933
Total volume weighted thermal resistance = 1956+955+933+933 = 4777
Green Guide rating correction = 3912 + 477 + 2799 +933 = 8121
Insulation Index: Green Guide Rating Correction/Total volume weighted thermal resistance = 8121/4777 = 1.7 (credit not achieved)
Please refer to the Calculation procedures in BREEAM issue Mat 01. Note, step 1 of the Calculation procedure outlined in BREEAM issue Mat 01 (the proportion of the total environmental impact of the assessed element) is not applicable for this issue as the insulation is assessed as a single material in BREEAM issue Mat 04 and not as part of a larger building element containing other materials (as in BREEAM issue Mat 01).