There are a number of elements that determine the overall performance of a project assessed using BREEAM; these are as follows:
- The scope of the assessment
- The BREEAM rating level benchmarks
- The minimum BREEAM standards
- The environmental section weightings
- The BREEAM assessment issues and credits
- How these elements combine to produce a BREEAM rating for a project is summarised on the following pages. This is followed by a description and example describing the methodology for calculating a rating.
- The BREEAM rating benchmarks for projects assessed using the BREEAM International New Construction 2016 scheme are as follows:
Table 3 BREEAM rating benchmarks
| BREEAM Rating | % score |
|---|---|
| OUTSTANDING | ≥ 85 |
| EXCELLENT | ≥ 70 |
| VERY GOOD | ≥ 55 |
| GOOD | ≥ 45 |
| PASS | ≥ 30 |
| UNCLASSIFIED | < 30 |
The BREEAM rating benchmarks enable a client and all other stakeholders to compare the performance of a building with other BREEAM rated buildings of the same type, and the typical sustainability performance of a stock of buildings.
In this respect each BREEAM rating broadly represents performance equivalent to:
- Outstanding: Less than the top 1% of buildings (innovator)
- Excellent: Top 10% of buildings (best practice)
- Very Good: Top 25% of buildings (advanced good practice)
- Good: Top 50% of buildings (intermediate good practice)
- Pass: Top 75% of buildings (standard good practice)
An unclassified BREEAM rating represents performance that is non-compliant with BREEAM, in terms of failing to meet either the BREEAM minimum standards of performance for key environmental issues or the overall threshold score required to achieve at least a Pass rating.
Calculating a building's BREEAM rating
A BREEAM Assessor must determine the BREEAM rating using the appropriate assessment tools and calculators. An indication of performance against the BREEAM scheme can also be determined using a BREEAM Pre-Assessment Estimator. The Pre-Assessment Estimator is available from the BREEAM website: http://www.breeam.com/projects/. Any pre-assessment estimate of the rating a project may achieve should be informed by a licensed BREEAM Assessor who understands the full details of the process where this is used to inform business, funding or contractual decisions.
The process of determining a BREEAM rating is outlined below and an example calculation included in Table 6.
- Firstly, the scope of the project being assessed needs to be determined, i.e. Shell Only or Shell and Core. The appropriate BREEAM assessment tool or calculator then adjusts the scoring and weightings to reflect the categories and individual credits assessed.
- The BREEAM Assessor will then determine for each of BREEAM's nine environmental sections (as applicable) the number of 'credits' awarded. This must be determined by the BREEAM Assessor in accordance with the criteria of each assessment issue (as detailed in the technical sections of this document).
- The percentage of 'credits' achieved is then calculated for each section.
- The percentage of 'credits' achieved in each section is then multiplied by the corresponding section weighting. This gives the overall environmental section score.
- The section scores are then added together to give the overall BREEAM score.
- The overall score is then compared to the BREEAM rating benchmark levels and, provided all minimum standards have been met, the relevant BREEAM rating is achieved.
- An additional 1% can be added to the final BREEAM score for each 'innovation credit' achieved (up to a maximum of 10% and with the total BREEAM score capped at 100%).
Table 6: Example BREEAM score and rating calculation
| BREEAM section | Credits achieved | Credits available | % of Credits achieved | Section weighting (fully fitted) | Section score |
|---|---|---|---|---|---|
| Management | 10 | 20 | 50.00% | 0.12 | 6.00% |
| Health and wellbeing | 17 | 21 | 80.95% | 0.14 | 11.33% |
| Hazards | 1 | 1 | 100.00% | 0.01 | 1.00% |
| Energy | 16 | 34 | 47.05% | 0.19 | 8.94% |
| Transport | 5 | 11 | 45.45% | 0.08 | 3.63% |
| Water | 5 | 9 | 55.56% | 0.06 | 3.33% |
| Materials | 10 | 14 | 71.43% | 0.125 | 8.92% |
| Waste | 3 | 13 | 23.07% | 0.075 | 1.73% |
| Land use and ecology | 5 | 5 | 100.00% | 0.10 | 10.00% |
| Pollution | 9 | 12 | 75.00% | 0.10 | 7.44% |
| Innovation | 2 | 10 | 20.00% | 0.10 | 2.00% |
| Final BREEAM score | 64.32% | ||||
| BREEAM Rating | VERY GOOD | ||||
Table 7 Minimum standards for a BREEAM Very Good rating
| Minimum standards for BREEAM 'Very Good' rating | Achieved? |
|---|---|
| Man 03 Responsible construction practices | Y |
| Hea 01 Visual comfort | Y |
| Hea 02 Indoor air quality | Y |
| Hea 09 Water quality | Y |
| Ene 01 Reduction of energy use and carbon emissions | Y |
| Wat 01 Water consumption | Y |
| Wat 02 Water monitoring | Y |
| Mat 03 Responsible sourcing of construction products | Y |
Producing case studies for BREEAM ‘Outstanding’ rated buildings
Projects certified to the BREEAM ‘Outstanding’ rating should act as exemplars for the industry. If they are to do this, case studies of these projects are needed so that other project teams and clients can refer to them.
Prior to Final Certification, the design team and client for BREEAM ‘Outstanding’ rated projects are asked to provide either a case study of the building or information to allow BRE Global to produce a case study. This information will be requested at the final Post-construction stage and should be provided with the BREEAM Assessor’s Final Certification Report.
BRE Global will publish the case study on the BREEAM website, Green Book Live website and in other BRE and BREEAM-related publications.
BREEAM assessment issues and credits
BREEAM International New Construction 2016 consists of 57 individual assessment issues spanning the nine environmental categories, plus a tenth category called ‘Innovation’ (described below). Each issue addresses a specific building related environmental impact or issue and has a number of credits assigned to it.
BREEAM credits are awarded where a building demonstrates that it meets the best practice performance levels defined for that issue, i.e. it has mitigated an impact or, in the case of 6.0 Health and wellbeing, addressed a specific building occupant-related issue, e.g. good thermal comfort, daylight or acoustics.
The number of credits available for an individual assessment issue will vary and generally the higher the number there are for a given issue, the more important that issue is in terms of mitigating its impact. In most cases, where there are multiple credits available, the number awarded is based on a sliding scale or benchmark, where progressively higher standards of building performance are rewarded with a higher number of credits.
It is worth noting that, in addition to the environmental sections, and overall score and BREEAM rating, verified performance against individual assessment issues also provides users with a credible set of key building performance indicators for a range of embodied, operational and construction phase building impacts. In this respect, in addition to using BREEAM to define overall targets, it is possible to use the method to define performance levels in support of specific organisational policy objectives for individual environmental issues. Care should be taken when setting design targets using individual issues and credit levels in this way as it can limit design flexibility and have an impact on project costs.
Awarding credits for innovation
It is one of the aims of BREEAM to support innovation within the construction industry and its supply chain. BREEAM does this by making additional credits available for the recognition of sustainability related benefits or performance levels which are currently not recognised by standard BREEAM assessment issues and criteria. By doing this BREEAM is rewarding buildings that go beyond best practice in terms of a particular aspect of sustainability, i.e. where the building or its procurement has demonstrated innovation.
Awarding credits for innovation enables clients and design teams to boost their building’s BREEAM performance and, in addition, helps to support the market for new innovative technologies, and design or construction practices.
There are two ways in which BREEAM awards ‘innovation credits’ to recognise innovation in building design and procurement. The first is by meeting exemplary performance criteria defined within an existing BREEAM issue, i.e. going beyond the standard BREEAM assessment criteria and therefore best practice. Note, not all assessment issues have exemplary performance criteria. The second route is where an application is made to BRE Global by the registered project’s BREEAM Assessor to have a particular building technology or feature, design or construction method or process recognised as ‘innovative’. If the application is successful and subsequently compliance is verified, an ‘innovation credit’ can be awarded.
An additional 1% can be added to a building’s overall score for each ‘innovation credit’ achieved. The maximum number of ’innovation credits’ that can be awarded for any one building is 10; therefore the maximum available additional score for ‘innovation’ is 10%. The building's final BREEAM score will be capped at 100%. Innovation credits can be awarded regardless of the building’s final BREEAM rating, i.e. they can be awarded at any BREEAM rating level. Refer to the Inn 01 Innovation section for more detail.
BREEAM International New Construction 2016
Reference: SD233 – Issue: 2.0
Date: 03/07/2017
Copyright © 2017 BRE Global. All rights reserved.
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