Sustainable development is becoming an everyday part of life for property developers, designers and contractors, as many people both inside and outside the construction industry are demanding that the environmental impacts of buildings are kept to a minimum. NBS Technical author and BREEAM Education Assessor, Bill Clark, briefly explains the broad principals of BREEAM and how some of the various credits contained within BREEAM schemes relate to the RIBA Plan of Work.
BREEAM is a voluntary scheme that aims to quantify and reduce the environmental burdens of buildings by rewarding those designs that take positive steps to minimize their environmental impacts.
Various schemes exist, covering different types of buildings:
- BREEAM Courts
- BREEAM Industrial
- BREEAM Multi-residential
- BREEAM Offices
- BREEAM Prisons
- BREEAM Retail
- BREEAM Education
- BREEAM Healthcare.
In addition BREEAM Ecohomes may be used to assess refurbished housing in England and for all housing in Scotland and Wales, whilst the Code for Sustainable Homes, based on Ecohomes, may be used for the assessment of all new housing in England. English Partnerships requires that all its developments must achieve a BREEAM rating of Very Good or better.
Other BREEAM schemes include BREEAM Bespoke, which deals with categories of building falling outside those described above, and BREEAM International, which is suitable for multi-national organizations wishing to adopt a common approach in different parts of the world.
Many organizations already require use of BREEAM schemes when carrying out major refurbishments or new developments. For example, the Office of Government and Commerce (OGC) requires a BREEAM rating of Excellent for all new buildings, whilst the Department for Children, School and Families (DCSF) requires all major new-build and refurbishment school projects – valued at over £500,000 for primary schools and £2m for secondary schools, and involving rebuilding or complete refurbishment of more than 10% of the floor area – to be assessed using BREEAM Schools.
Projects are assessed using a system of credits in ten categories:
- Health and wellbeing
- Land use and ecology
The credits are awarded according to the environmental impact of the development judged objectively against a rigid set of criteria. Certain credits are common between schemes, while some are unique to an individual scheme.
During the assessment process, credits are added together within each category and an environmental weighting is applied to the scores. A single overall score is then produced which results in the building being rated on a scale of Fail, Pass, Good, Very Good, Excellent, or Outstanding.
Stages A and B
Many of the decisions influencing the award of credits are taken early in the procurement process (RIBA stages A and B), particularly in the Management, Transport and Land use and ecology categories. These include the site to be used, e.g. proximity to good local transport links, risk of flooding, or contamination from previous use; and the decision to opt for new build or to reuse an existing structure or façade.
The early appointment of a BREEAM Assessor, and early BREEAM assessment, make it easier and more cost effective to achieve a higher rating. For example, issues such as the orientation of a new building, as well as the overall building concept, affect its energy efficiency. Understanding how the building will function and be managed, where surface water will go, and what users are likely to do about lighting, ventilation and recycling waste, all need to be incorporated into the design approach.
Design teams must work together to enable the maximum number of credits to be accrued, and consideration must be given to whole life costs, requiring the various designers to work in a coordinated way, with the whole team committed to working within the sustainability agenda. Designers must also consult with end users.
Ideally, building services engineers, historically appointed later in the process, should be brought on board as early as possible, because many of the credits available are weighted towards highly efficient energy performance and very low levels of CO2 emissions. In particular, the use of natural ventilation and avoidance of refrigerants is likely to score favourably, so their ability to influence orientation and building form is vital.
Other specialists – for example those involved in aspects of whole life costing, ground sampling, or the assessment of the local ecology – must similarly be involved early. Failure to do so means the opportunity to gain credits against those criteria will be lost.
Credits may also be awarded through other work stages. In the detailed design stages (D and E), materials are selected for the major building elements of walls, windows, roofs, upper floor slabs and floor finishes and coverings. Similarly, components are selected at this stage to serve systems such as lighting and heating, and decisions are made about the use of energy from renewable sources. Care does need to be taken when ‘value engineering’ since substitution of materials with a lower capital cost may not only fail to meet the designers’ specified requirements but may also mean that credits for the BREEAM assessment are withheld – potentially a major problem where developments rely upon gaining Very Good or Excellent BREEAM ratings to satisfy funding providers.
Finally, contractors (typically involved from Stages J to L on a traditionally procured development) also have a major part to play because the BREEAM schemes make credits available for the environmental impact of the construction process, rewarding good construction practice, including use of the Considerate Constructors Scheme, and mitigation of construction site impacts.
NBS is now incorporating guidance in NBS Building, NBS Landscape and NBS Engineering Services, to assist specifiers in the selection of systems and products that may contribute to the award of BREEAM credits. Meanwhile, further information on the various BREEAM schemes is available on the BREEAM website www.breeam.org .