Sustainability: a global perspective

Prof Roger Plank
President at Institution of Structural Engineers
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Post date: Friday, 13th January 2012

President of the Institution of Structural Engineers, Prof Roger Plank, assesses the growing significance of sustainability and Building Information Modelling (BIM).

As governments and society become more engaged with the need for sustainability, and the threat presented by global warming in particular, the pressure to minimise the carbon footprint of buildings grows.

This trend is set to continue with more demanding legislation from governments, greater financial incentives (or penalties for inefficient construction), and increased recognition by clients that they need to demonstrate their own commitment to sustainability.

Structural engineers will therefore need to develop an understanding of sustainability in general, how this might influence design and construction, and specifically how to quantify the embodied carbon content of a project. What constitutes sustainable construction is not clearly defined, and the indicators extend across a wide range, involving a myriad of parameters. Achieving a solution often involves a degree of qualitative judgement in which different aspects of the building have to be balanced.

In comparison, calculating the embodied carbon of a building is relatively straightforward, but even this involves data which lacks the precision with which structural engineers are generally more familiar.

Although still relatively small in most cases compared with emissions in use, this embodied carbon is becoming ever more important as a result of improved energy efficiency in the operation of buildings. As the structure typically contributes about half of the total embodied carbon content of the building fabric, structural engineering is of critical significance, and we should be prepared to take on this additional responsibility.

BIM is not a new concept, but it is rapidly becoming a reality in practice. Those who have some experience of using BIM attest to the enormous potential benefits which are offered through the ability to share intelligent information about the building through all aspects of design, construction and in use.

It will require a new way of working with even closer cooperation between members of the design team, who will share a common model, but it should ensure much better coordination of data and importantly, any changes are shared by all parties. It offers increased opportunities for structural engineers with potentially a deeper involvement in areas such as construction planning and affords contractors the possibility of much leaner tendering.

Although BIM could be used to deliver what is done now but more efficiently, the real benefit comes from being able to offer a much more comprehensive service. There will of course be some initial drop off in productivity as companies seek to train individual staff in the new approach, and there is some modest investment required in the technology to support this, but experience indicates that net benefits can be realised very quickly.

One further possible change in the landscape of structural engineering practice relates to the growing recognition that a minimum level of competence should be required of those responsible for structural engineering projects.

The consequences of structural failure are clear, and although some independent controls and checks are provided by the current approvals process, it seems logical that some form of certification or registration should be implemented. Such schemes are well established in many countries, and are spreading.

Typically these require a minimum level of qualification and experience, as well as ongoing evidence of professional development, thereby providing some confidence in the currency of the skills and knowledge of individual practitioners. These developments offer challenges but more importantly opportunities for structural engineers. At present the economic climate has significantly depressed construction activity, and it is tempting to simply scale down our capabilities. Alternatively the current reduced level of activity could be used to come to grips with these emerging issues.

There are, of course, other developments which will demand the attention of structural engineers. The introduction of the Eurocodes is perhaps the biggest of these, and this in itself will require the adoption of approaches which are radically different in detail from many of those familiar to us.

We are also facing changes in the conditions for which we design and construct, associated with, for example, varying weather patterns and sea levels. Globalisation of the construction industry, especially in relation to design, also means that we are often faced with unfamiliar requirements. For instance, whereas designers based in the UK have traditionally not been concerned with seismic conditions, those same engineers are frequently finding it a major aspect of many of the projects on which they are engaged.

All of these developments place an increasing responsibility on practising engineers to keep abreast of relevant changes, and society will expect us not only to do this, but demonstrate that we have done so.

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