33 shades of sustainability

During her research, master student civil engineering Darinde Gijzel became a linking pin between the municipality of The Hague’s project office for a new tunnel called ‘Rotterdamsebaan‘ and a sustainability expert team led by her Professor Marcel Hertogh writing an inspiration document on various aspects of sustainability in the context of tunnels.

Gijzel presented her thesis at the end of a mini symposium called Tunnel visions on sustainability last week. Before her presentation, there were talks from Rene Teule, head of infrastructures in The Hague (and commissioner of the Rotterdamsebaan tunnel), Paul Janssen MSc. (project leader of numerous tunnel construction projects) and William van Niekerk MSc. (director CSR Royal BAM Group).

A sustainable tunnel seems a contradiction in terms when you consider the extra material and energy needed for tunnel construction in comparison to a normal road.

However, once it has been decided that a tunnel should be constructed, you can do it in more energy-efficient, ecological, environmental friendly ways by for instance reusing materials and minimising waste. 

In fact, when Gijzel made an inventory of possible aspects of sustainability in literature and interviews with experts, she arrived at a whooping 102 different aspects in total.

After filtering the list and consulting with industry experts, she reduced the list to 33 items covering four different perspectives: energy (energy use, efficiency and CO2 emissions), resilience (maximising its functionality and value), social (strengthening the bonds with local inhabitants) and transition (preventing harmful effects on people and planet).

These perspectives sometimes converge. For example in transport, noise, water usage or construction waste there’s little dissent. But on other topics, different perspectives lead to conflicting views. Functional flexibility for example scores high from the points of view of transition and social function, but it is not the most efficient way to arrive at a sustainable tunnel, therefore the energy perspective –with an efficiency approach- assigned this aspect a low score. 

Therefore, Gijzel argues, the commissioning party, the community of The Hague in this case, should establish a clear and ambitious definition of a ‘sustainable tunnel’ based on their selection of sustainability aspects for their specific project. 

Contrary to its name perhaps, the European EMAT (Economically Most Advantageous Tender) is a powerful tool to include (non-economical) sustainability aspects in the tendering process. 

Van Niekerk (BAM) said: “Sustainability is competition.” He would like to see a fixed-price tendering (which is not yet the case) so that competitors can profile themselves by creating extra value – be it led lighting in the tunnel, landscaping of the entries, filtering of the exhaust air, minimising transport nuisance or whatever else.

It’s up to the commissioning body of course to judge whether the extras on offer are in line with its own sustainability definition earlier in the process.

And, says Gijzel, sustainability consists of many different aspects. Each of them contains a challenge for current and future engineers. It’s up to the engineers to find solutions to these sustainability challenges. That certainly applies to a market where sustainability solutions are part of the competition process.

–> Darinde Gijzel, Tunnel Visions on Sustainability, A research on sustainability and its selection process for road tunnel projects, Master thesis supervisor: Prof. Marcel Hertogh (CEGS), 19 June 2014.