Ecobuild asks ‘How green is tall?’

Amongst the overwhelming massiveness of Ecobuild is a secluded room where the ‘design, architecture & sustainability’ conference series took place. There high profile figures from the profession present and debate current issues, through a ’sustainability’ lens.

Tuesday’s How green is tall? seminar brought together a crowd of over 300 people to hear a panel debate the topic of sustainable tall buildings. Chaired by architectural critic Rowan Moore, the panel included Ken Shuttleworth of Make Architects, structural engineer Richard Mawer of WSP (and member of the Shard structural engineering team) and structural engineer Jane Wernick of Jane Wernick Associates.

Make Architects' proposed groundscraper, 5 Broadgate

The first round saw each panel member present their views on sustainable tall buildings in five minute slots. Ken Shuttleworth and Richard Mawer both fought the corner FOR tall buildings and debated which one of their current projects -  Make’s 5 Broadgate and Piano’s Shard - was more ‘green’. Ken Shuttleworth used figures to make his point, stating the Shard would generate double the carbon emissions of 5 Broadgate. Richard Mawer hit back stating that the Shard will only have 48 car parking spaces; therefore the energy used to run the building would be off-set by occupants travelling by public transport to the Shard and not by car.

Renzo Piano's Shard

Renzo Piano's Shard

One clear issue which came out of the initial presentations by Ken and Richard were that tall buildings were a risk and demanded commitment. There is significant time required to develop a tall building and to get all the provisions in place before the project can begin on site. During this time the regulations change and new technologies are available forcing the project to play catch-up. Ken admitted that if he was working on the Gherkin today, then it would have a different façade on each side to respond to the orientation.

Jane Wernick fought the corner AGAINST tall buildings and made a good case for a low-rise city like Paris. Stating her views on why tall buildings are not a sustainable form of development, she discussed lack of permeability at ground level, affect on mental health of occupiers and difficulty to maintain tall buildings to a high standard.  She is of the view that if tall buildings are built then they need to be maintained for as long as possible to maximise the longevity of the building.

Judging from the crowd’s reaction, round two’s lively debate was the most entertaining moment of the talk, quickly focusing on the Shard’s lack of solar shading. Richard Mawer clarified that the solar strategy relies on automatic internal blinds to provide shading. Ken claimed the Shard was a greenhouse, and oddly Richard agreed. On a building of such a massive scale, is an internal shading system the right option?  Other elements of the Shard were discussed which were more favorable. The Shard has been designed to accomodate a retrofit, a recurring theme in Ecobuild this year. All floor joists feature a continuous run of perforations to accommodate new services and altered drainage layouts. This also lightens the weight of the steel work, reducing the amount of structure required.

The seminar clearly articulated two strong schools of thoughts FOR and AGAINST tall buildings. The panel agreed that the market would continue to demand tall buildings in urban areas for reasons including the cost of land, maximising floor area and accommodating large numbers of people. Therefore we need to develop sustainable tall buildings. Tall buildings should be designed to consider maintenance and adaptability for future alterations, ensuring longevity to make the process of developing and sustaining tall buildings worth it.

So how green is tall?. The jury is still out.

by Michelle Price, AJ sustainability intern

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