Building LCA – Scope when a BREEAM Assessment covers only part of the new building design - KBCN1172
To give reliable results, building LCA 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 building LCA the designer may choose a design option that optimises environmental impacts for the limited part analysed, but will be unaware of potential detrimental effects to the overall environmental impact of the building.
In addition, if a building LCA 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, the building LCA scope should normally include the whole building design (as defined in Mat 01, ‘Scope of assessment’) even if the area covered by the BREEAM assessment scope is only part of the building.
However, where in the opinion of the BREEAM Assessor this is not reasonable, it is acceptable for the building LCA scope to match the BREEAM assessment scope. Examples where this may be the case include newly-constructed, mixed-use buildings (where the different use zones are assessed under different schemes or some are not being assessed at all) and part new-build part refurbishment projects.
Where this is the case:-
- Comparison with the BREEAM benchmark cannot be done, only options appraisal.
- Only include construction elements/components that are both:
Within or forming the boundary of the BREEAM assessment scope.
Predominantly the responsibility of the project team undertaking the building LCA work.
Note: Based on the above conditions, if no construction elements/components are included, or what is included is too limited to have significantly different options to appraise, then credits cannot be awarded.
- In the BREEAM Mat 01/02 Results Submission Tool:
Select ‘Other’ for the ‘BREEAM assessment building use type’ (note: ‘mixed-use’ should only be entered for mixed-use buildings where the whole building is included in the building LCA scope).
For ‘Functional quantity…’, enter the value corresponding to the scope included in the building LCA.
Include the following text in cell C10 of the ‘DifferencesID2,3,4’ sheet: “The scope of this building LCA work matches the BREEAM assessment scope, which covers only part of a building being newly constructed/refurbished. Of the areas being newly constructed/refurbished, the building use type(s) of the areas included in the building LCA scope are [insert use type(s)] and the building use type(s) of the areas excluded are [insert use type(s)]. The Functional quantity of the areas excluded are [insert value]”.
06-Mar-2024 - Scheme applicability updated to UK NC V6.
01-Dec-2020 - Clarification to previous update added.
27-Nov-2020 - Exceptions paragraph added.
06-Dec-2019 - Scope of KBCN clarified.
Building LCA – similar buildings approach - KBCN1459
If multiple buildings share an
identical design, as per
KBCN1226, the one set of LCA evidence can be submitted for (where pursued) the superstructure and core buildings services criteria for each identical building.
Where buildings are
similar, but not identical the following applies.
Level of variation
- For <10% variation in LCA results between the buildings, submit the Mat 01/02 calculator for only the worst performing design.
However, results for all buildings must be included in the LCA report.
- For ≥10% variation in LCA results submit the Mat 01/02 calculator for every building. See below:
Tool submission
Separate submissions are carried out in BREEAM Projects:
- Upload one zip file per building.
Each zip file will contain all required files as if for individual assessments. Clearly identify each building (e.g. the filename should contain 'Building A', 'Building B' etc).
- Identify the worst performing building.
By adding ‘_Worst Performing’ to the end of the filename.
Evidence submission
Separate and specific building LCA evidence for each building must be submitted for (where pursued):
- The superstructure and core buildings services criteria.
- The substructure and hard landscaping criteria.
These aspects will almost always vary irrespective of identical superstructure and core building services design.
Refer to the technical manual and relevant KBCNs on how to assign hard landscaping to each building on a shared site.
For options appraisals, common evidence covering all similar buildings can be used. There is no requirement for different design options for each building, although this can still be done if this brings value to the project.
04-Oct-2023 - Title and layout updated for clarity and consistency. Scheme applicability updated.
16-Nov-2021 - Revised and re-published.
Building LCA – evidence requirements for multiple assessments with identical designs - KBCN1226
Superstructure + core building services
Where an
identical superstructure design and / or
identical core building services design is used for multiple buildings, the same building LCA evidence may be submitted for all these assessments.
The following shall be identical:
- Products specified and quantities installed.
- Transport of the products to the site (10km variation in transport distance to site is acceptable).
- In-use assumptions (e.g. maintenance, service lives of products).
- End-of-life assumptions.
Substructure and hard landscaping
It is unlikely that the same substructure and hard landscaping design will apply to more than one building due to variations in ground conditions and site layout.
Therefore, it is not acceptable for the same substructure / hard landscaping LCA evidence to be submitted for this criteria for more than one assessment.
Similar buildings approach
If the LCA(s) are part of a similar buildings assessment, please also see
KBCN1459.
04-Oct-2023 - Link to KBCN1459 added. Scheme applicability updated. KBCN layout adjusted for clarity.
Time critical requirements – defining project stage by construction element - KBCN1156
This KBCN was originally written to specifically clarify BREEAM requirements for Mat 01 Concept / Technical Design under NC 2018 and V6. However, the general principles may also be applicable to other assessment issues.
As a building design process passes through successive work stages, increasingly more aspects of the design become fixed. BREEAM criteria often require actions at, before or after specific project work stages, as these are the optimal stages to achieve the required sustainability outcome. When undertaken at a different stage, the criteria may be difficult to comply with, opportunities may be missed, options limited or costs may become prohibitive.
Knowing which stage your project is at
Where possible, BREEAM refers to industry-standard work stages, for example the RIBA plan of work stages. However different project teams can interpret these referenced stages differently.
Furthermore, many projects do not follow these stages in a simple linear fashion for all aspects of the design at the same time. For instance, the envelope design may be well advanced even to the point where installation has commenced before any specification decisions have been made on some interior finishes. As such, a project may not be at one project stage for all elements of the design at any one point in time.
This Knowledge Base compliance note is intended to provide supplementary information to enable projects to determine what stage they are at with respect to time critical BREEAM requirements, including where different elements are at different stages. Although project team members may be willing to offer their opinion on the stage the project has reached, this will often be subjective and hence inconsistent. Therefore, the process set out here looks at the currently available design information for the project (e.g. drawings, specifications) to determine the current work stage in relation to the issue under consideration. This provides a more objective, demonstrable approach for the assessor to follow.
Concept Design Stage
The RIBA definition of ‘Concept Design’ (RIBA stage 2) can be found here
https://www.ribaplanofwork.com/PlanOfWork.aspx . The core objective given is
‘Prepare Concept Design, including outline proposals for structural design, building services systems, outline specifications and preliminary Cost Information along with relevant Project Strategies in accordance with Design Programme. Agree alterations to brief and issue Final Project Brief.’
Table 1 and table 2 (in the link below) provide further guidance, specific to BREEAM, to help determine whether a project, or part of the project relevant to the issue/credit, is at ‘Concept Design’ stage. If there is ambiguity or uncertainty about the stage of the project, the assessor should check with the design team whether the design documentation (drawings, specifications, BIM etc.)
currently being produced by the design team will generally include the information listed.
It is possible for different aspects of the project to be at different stages in terms of how progressed the design is. For example, the substructure design may be at technical design or even installed while the internal partitions are still at concept design. Whether this matters depends on the issue/credit being pursued. The following steps take this into account.
Step 1
First, for the issue/credit being pursued, determine which of the relevant assessment scope items in table 1 and 2 are relevant. For example, if the issue/credit only relates to substructure, then only the substructure assessment scope items shall be considered. If the issue/credit is of a general nature concerning the whole project, then all the assessment scope items shall be considered.
Step 2
For the relevant assessment scope items from step 1, decide which of the following applies the most: -
- Where the items listed are in the process of being included in the design documentation, this indicates that the project, or part of the project being considered, is likely to be at the ‘Concept Design’ stage.
- If items listed are not in the process of being included, the project, or part of the project being considered, is likely to be at an earlier stage.
- If the existing design documentation already includes the items listed the project, or part of the project being considered, is likely to be at a later stage.
Please note that the items listed are indicative of the typical information produced at ‘Concept Design’ stage.
Technical Design Stage
The RIBA definition of ‘Technical Design’ (RIBA stage 4) can be found here https://www.ribaplanofwork.com/PlanOfWork.aspx . The core objective provided is ‘
Prepare Technical Design in accordance with Design Responsibility Matrix and Project Strategies to include all architectural, structural and building services information, specialist subcontractor design and specifications, in accordance with Design Programme.’
The following provides further guidance, specific to BREEAM, to determine whether a project is at the ‘Technical Design’ stage: The RIBA plan of work definition of ‘Technical Design’ clearly states that it should ‘
…include all architectural, structural and building services information, specialist subcontractor design and specifications…’. Therefore, it is a simpler task to determine whether the project, or part of the project relevant to the issue/credit, is at this stage. If there is ambiguity or uncertainty about the stage of the project, the assessor should check with the design team whether the design documentation (drawings, specifications, BIM etc.) currently under production by the design team (and the contractor’s specialist sub-contractors, if applicable) will, when finished, generally include all the final design information required for the construction works on-site.
Like concept design, it is possible for different aspects of the project to be at different stages in terms of how progressed the design is. The following steps take this into account.
Step 1
First, for the issue/credit being pursued, determine which of the relevant assessment scope items are relevant (the assessment scope items given in table 1 and 2 may be used, but the rest of the information in these tables relates to concept design).
Step 2
For the relevant assessment scope items from step 1, decide which of the following applies the most: -
- Where all the final design information required for the construction works on-site is in the process of being included in the design documentation, this indicates that the project, or part of the project being considered, is likely to be at the ‘Technical Design’ stage.
- If it is not in the process of being included, the project, or part of the project being considered, is likely to be at an earlier stage.
- If the existing design documentation already includes all the final design information required for the construction works on-site the project, or part of the project being considered, is likely to be at a later stage.
KBCN1156_IndicatorTables
06-Nov-2024 - Scheme applicability updated. Title amended. Explanatory note added.
17-Jun-2019 - KBCN updated to provide additional guidance.
Information correct as of 24