Consistency, realistic targets and record taking are key to meeting environmental performance targets
For sustainability – as for most other issues – a clear and agreed brief is an essential starting point for any successful project. Just as important though is how that brief is carried through into tender and construction information.
With sustainability, while it is possible to rely on external ratings systems such as BREEAM or on project specific sustainability plans, these seldom carry as much weight with contractors as the specification, unless they are made a contract document. Bennetts Associates’ project at Five Pancras Square, in London’s King’s Cross, which achieved one of the highest ever BREEAM ratings, did so in part because an ambitious client made the rating a contract document.
It is not a route open to all projects. But there are some simple principles that make sustainability more likely to be carried through.
Achieving your goals
Two consistent stumbling blocks to achieving sustainable architecture are the setting of unrealistic targets and the use of misunderstood or incomparable units – for example carbon and carbon dioxide are often conflated and conversion factors not clearly stated. Prompting teams on all projects to use the same terminology and units makes data easier to collect and compare, which in turn makes the setting of ambitious yet realistic targets more informed.
We use as a primary focus the six key environmental performance indicators that were employed as part of the post Egan Report Movement for Innovation: operational energy, embodied energy, transport energy, water use, site waste and biodiversity
At Bennetts Associates we have started to use the specification – from the brief, through the outline,full and finally record stages – as the primary means of stating, embedding and recording sustainability targets. This is done by using a common data template across all projects, which captures a number of benchmarked sustainability indicators.
Benchmarking is essential if briefing targets are to be properly understood. The collection of record and post occupancy evaluation data is essential to closing the loop between aspiration and experience.
We continue to use as a primary focus the six key environmental performance indicators that were employed as part of the post Egan Report Movement for Innovation: operational energy, embodied energy, transport energy, water use, site waste and biodiversity. These are understood to varying degrees across the industry and the quality of information varies, but they do provide six numeric measures, which is invaluable in a field where data and rhetoric are often conflated.
Keep it all connected
The new NBS Create system also helps with retaining a link between the brief and outline, full and record specifications. With the previous NBS Building Specification any introduction or preamble tended to be within Section A, which was usually completed by the quantity surveyor, often with little input from the rest of the design team.
However, an introduction to the project and the key briefing targets can easily be located in the whole building performance section of NBS Create. Its structure means it can be used to write a simple brief that is then filled out to form the outline specification and to which, in turn, more detail is added to become the full specification. The principle of using a consistent data template is just as applicable using other authoring programmes and methods. It’s important that the whole building performance section is a short as possible. It should be able to communicate the essence of the project in a page and its key design parameter data in a second one. More than that, it will at best be scan read by most people.
Agreeing stated targets and assumptions early, and then being clear that in the event of inconsistencies the brief takes precedent, places the onus on each consultant to check that its own information is consistent with the aims of the project
Having consistent targets, with progressively more detail added, throughout the design and construction of a project helps to ensure that key briefing data isn’t hidden within various consultants’ work stage reports. Perhaps more importantly, agreeing stated targets and assumptions early and then being clear that in the event of inconsistencies the brief takes precedent, places the onus on each consultant – including the architect – to check that its own information is consistent with the aims of the project.
The right questions at the right time
The common data template can also be a mechanism for ensuring that the right questions are asked at the briefing stage. Alongside those six key environmental performance indicators, two fundamental briefing questions concern the use of CIBSE’s TM54 to carry out energy modelling and implementation of the Soft Landings Framework. Together these link predicted energy use and the actual operation of the building. Energy performance certificates are often misunderstood as energy predictions, which they are not. They are in fact merely an energy rating and one where the baseline changes for each building, so they are incomparable in any meaningful sense. Both TM54 energy calculations and Soft Landings are comparatively easy to include at the outset of a project, but become progressively more difficult to add as it progresses.
Clearly there are many factors at play in the creation of more sustainable buildings, but having short introductions with agreed benchmarks to project briefs and specifications goes a long way. It is all about communication and, while no great innovation in itself, it is one more step on the road to sustainability.
Peter Fisher is a director at Bennetts Associates and a member of RIBA Sustainability Futures Group
The RIBA is developing a briefing & evaluation toolkit with beta launch due at the end of 2016