WAF Newsletter - Sustainability in Dubai - October 2021

 

Sustainability in Dubai

Jeremy Melvin, 28 October 2021


An autonomous building producing its own water and power in the Dubai desert is an apparent contradiction, writes Jeremy Melvin

The emirate’s recent development, turbo-charged by oil, certainly belies sustainability, while the arid environment might seem to preclude it. The challenge for the invited entrants to the 2015 competition – won by Grimshaw – for a sustainability-themed pavilion at the projected 2020 Expo in Dubai (which thanks to Covid opened in 2021) was to unpick that contradiction.

On top of this, the brief posed another formidable challenge. Most expo pavilions, however innovative and attractive their design, are scrapped after six months or so. Here the client, Emaar, recognised that this hardly reinforces the message of sustainability and so determined that its pavilions should have an afterlife or legacy. For the duration of the expo itself, the pavilion would be one of the main magnets for the projected millions of visitors; afterwards it would transform into a sustainability centre, still with numerous visitors, but also providing public facilities for exhibitions, talks and lectures and a restaurant, to support the start-ups and research organizations who were expected to occupy neighbouring buildings. Given the longer life of the ‘legacy mode’, the designers set out to resolve this and then work out how to ‘pre-fit’ it for the Expo.

Terra, as the sustainability pavilion is named, is one of three themed pavilions – the other two are mobility and innovation – which set the tone in content and design and lend their names to their districts of the site. This follows the overall theme of the Expo of ‘Connecting minds, creating the future’ (coincidentally rather like the theme of this year’s year’s Venice Biennale of how we can live together) and the specific challenge facing oil rich states in respect of survival as the world moves to power sources other than oil.

The pavilion design that has resulted shows that in the desert sustainability need not be an oxymoron. Grimshaw were armed with their experience of sustainable design, their knowledge of visitor attractions, their previous foray into expo pavilions (the UK’s at Seville 1992) and a formidable team of consultants. These included their long-term client collaborator for the Eden Project, Tim Smit, Buro Happold as engineer, landscape designers Desert Ink, exhibition designers Thinc, and theatre consultants Charcoal Blue. The architects, working with a client desperate to prove that life could continue in the desert without oil, have achieved a remarkable result.

One of the largest pavilions on the Expo site, it soars above its neighbours in the sustainability district. Inspiration for the form comes from the desert-resilient ghaf tree, which has a wide canopy that remains green in arid conditions and rests on minimal trunks. The 135m long roof with a 70m cantilever rises from a central hollow trunk of steel columns, sloping upwards towards the end of the cantilever. Angled and shaped to strengthen the passive effects of the landscape and sculpted ground including funneling air movement, its structural and visual gymnastics make it appear to shelter its neighbours, while shading its immediate precinct, with the roof dappling and reflecting sunlight before it reaches the level where people walk.

Shade in Dubai, where external temperatures reach 50 deg C, can make the difference between a bearable or unbearable external environment. This reflects the first goal of sustainable design, as Grimshaw chair Andrew Whalley puts it, which is to reduce the energy demand. That means deploying all the elements, from roof and wall to site and landscape in the overall proposition, whether active or passive.

Working with site conditions, local flora and materials is another cornerstone of sustainable design. Over millennia, this part of the desert has evolved its own complex and sophisticated eco-system. It may be less dense than temperate climates can sustain, but local animals and plants have adapted to the condition. For the last few millennia, humans have found a way of fitting in, knowing where water might be, where plants could be found both for animals and themselves, and above all to respect the ground formation that governs water flow and distribution, and thereby the capacity to sustain life.

Various aspects of these conditions flowed into the design. There were numerous cues to explore bio-mimicry. The local materials supply chain invited investigation, to understand the capabilities it had to avoid energy-intensive, long-distance transportation – as well as grounding the building in its cultural context (an important consideration for the client). Then there was the possibility of using the ground itself. In Dubai, a few metres below the surface the temperature is much cooler and more stable than above. Sinking much of the building into the ground became an obvious design move. This would be ideal for exhibition halls with large crowds of visitors.

Using the ground’s characteristics in this way helped to give an identity to the pavilion’s two incarnations. During the Expo, visitors are led on a walk through the landscaped precinct around the pavilion, then down a ramp into the courtyard defined by the roof columns, a route which also enables queue management, with visitors waiting amid the soothing effect of plants and in the shade. Descending the ramp takes visitors from the hot outside to the cooler subterranean realm – the temperature shift is noticeable.

To enhance the effect, immediately above ground the walls are clad in stone from local mountains. This stone, which shares the colour of the sand, cuts energy- intense transportation while its high thermal mass drives down the need for cooling. Once at the lower level, various exhibition areas radiate outwards. After the Expo closes, the entrance moves to the ‘front’ of the building, under the cantilever, into what is obviously the foyer of a public building, with clear routes down to the galleries, sideways to the café or, via elevators or a walkway, to the roof.

There were other opportunities resulting from the supply chain, especially in respect of local suppliers and fabricators. Though the structure requires extensive use of steel, Buro Happold worked their structural engineering magic to reduce the initial quantity projected by up to 50 per cent. As much as 97 per cent is recycled in a plant 15 minutes from the site, reducing embodied energy in production and transportation. Overall, the building has 41 per cent less embodied carbon than an equivalent new building. Involving local businesses and their employees in the project has the additional benefit of making it seem part of their lives, which can be extended by giving them an engaging experience when they visit.

The measures described so far are about passive design and reflect established good practice. But the goal was to go further – to make an exemplar building that achieves what even a decade or two ago would have seemed impossible. This has meant various different systems working together, territory where Grimshaw are very skilled – for example much of their work such at the Seville Pavilion and the Eden Project were exploring this condition in the 1990s. As noted, the first step is to reduce energy load, and then to look at the supply chain to reduce embodied energy. The next and most innovative stage is to understand how local eco-systems work, exploring whether their techniques and methods can be adapted by technological ingenuity to achieve something similar in a product of artifice rather than nature. 

This brings us to bio-mimicry. If the ghaf tree provided inspiration for the overall form, it also created the basis for technological enhancement beyond offering shade. Covering the enormous roof area of 8,000 sqm with 1,055 solar panels creates an active power generator. But even that would not meet the whole 4GWh load needed every year. So the idea of a series of ‘energy trees’ was born to provide the extra power needed. These are spread throughout the landscaped precinct and draw inspiration from the Socotra dragon tree, which comes from islands in a nearby archipelago in the Gulf.

Image: Water tree

The canopies of these ‘trees’ also provide shade and power, their undersides incorporating more photovoltaics to exploit reflected light. Unlike the roof canopy, and rather like a sunflower, they can move to track the sun, which means they generate about 25 per cent more power than if they were stationary. They move too slowly for it to be visible to the naked eye, but over the course of a day their changing position becomes apparent, adding a slow performative layer to the more rapid movement of visitors.

‘Trees’ to trap water from the air adapt the same basic structure. Dubai, given its coastal location, unlike the interior of Saudi Arabia, has reasonable humidity in the air. As with all deserts, there is a large diurnal temperature range, and the drop at nighttime cools the inner surface of the tree’s cones, allowing water to condense, which is then gathered and trapped to irrigate the landscape. Again, this uses artifice to adapt and strengthen what nature can do anyway, but with greater effect and efficiency. Each ‘tree’ produces a daily average of about 30 litres. There is also some brackish water which can be desalinated, while separate research is exploring the potential of salt as a construction material. In an example of circular economy potential, serving the building’s users helps to provide sustainable materials for other buildings. Water is also cleaned and recycled – including blackwater through a reed bed, whose extraordinary growth is testament to the power of human waste, helping the building achieve its goal of self-sufficiency in water as well as power.

Gven the excitement about technology and the urgency of addressing climate change, it is easy to describe the pavilion via the conventions of scientific thinking. But emotion is central to the experience which the design team seeks to generate for visitors. The first element of this aspiration is the landscape, which as mentioned above provides the setting for the promenade to the entrance. Its paths meander around planted beds and the trunks of the ‘trees’, both of which can attract attention. The plants are all local, so they are both adapted to the climate and familiar to most visitors who come from the region. All this subtly underlines the message that sustainability is something with which everyone needs to engage, not just woke northern Europeans or eccentric scientists. This gentle didacticism continues in several ways: the hard landscaping uses materials that are either local or largely recycled, while for anyone who wants to take understanding of sustainability to a deeper level, there are plenty of cues to follow. The landscape continues via a ramp to the rooftop restaurant.

Tim Smit, client of the Eden Project and a driving force behind the displays at Terra, reinforces the purpose of appealing to emotions in inculcating the message about sustainability. He has coined phrases such as ‘wood wide web’ to introduce people to the high level of communication that exists between plants to support each other.

In line with the aim of driving down power consumption at conceptual stage, the displays were given a limited allocation of electricity. That ruled out energy-guzzling aquaria but did allow for several specially commissioned artworks, and displays that explore a wide range of phenomena from forests to consumerist detritus. They can change periodically to reflect new technologies and new research, which will underline the centre’s relevance in its legacy mode. Meanwhile the 250-seat auditorium, an addition to the brief by Grimshaw themselves, can be used for presentation either to the public or for scientific peer comment.

No-one will be drawn on the cost of the pavilion. But in one sense this is irrelevant. If it succeeds in engaging people with ideas about sustainability at an emotional level, part of the brain that governs innovation as well as pleasure, it will pay for itself many times over. It will have succeeded where prophets of doom and erudite scientists have yet to succeed, convincing us to embrace sustainability not just as an urgency, but as a pleasurable intellectual challenge.

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