Face-to-face
Dr Ken Yeang of Llewelyn Davies Yeang is a world leading architect in ecological design and passive low-energy design. He tells Duncan Johnson what it means to design and build sustainably, as featured in ‘As nature intended’ in RICS Business May
Take up of sustainable technology remains slow – are many green products still an unknown quantity?
I think if you asked me about 10-15 years ago I would have said yes, most green technologies are untested. Historically, the industry has been hesitant.
During the ‘70s the architect Sir Colin Stansfield Smith did a lot of low-energy schools but he received regular complaints that his systems did not work. When he came to look at the problems he found that the majority of issues were down to the buildings not being used properly.
Today, since the 1990s things have advanced quite a bit and technologies continue to develop very rapidly. This is one of the major concerns of developers – the engineering is changing so fast that it is very difficult to keep up.
Technology has moved, increased and improved so fast that often developers simply don’t know what to do with it. But the situation is obfuscated by the great swathe of eco-wannabees. Over the last ten years almost every architect in the world has wanted to become green but they don’t have a background in design, in green design. So they read what they can in the magazines and decide the thing to do is to call in the mechanical engineer – to engineer a green solution.
So what does it mean to design and build sustainably?
I see schemes by famous architects, names I couldn’t possibly name who have been designing in the same way for 20 years but they bring in a mechanical engineer and make it green.
I was in Rotterdamn and a client pointed to a building and exclaimed, “it’s green.” “Green?” I asked. “Yes, LEED Platinum,” she answered.
“But it looks like the same building that architect has been designing for 20 years?” There is a perception that if it’s LEED Platinum, then it’s green, which worries me.
My view can be understood in terms of an eco-masterplan, where the following four infrastructures must be in place, woven together as a holistic whole:
Grey – Eco technology, whatever’s the flavour of the day
Blue – Water. Water management and sustainable drainage. We should try to close the entire water cycle loop on a site
Red – The colour of blood and represents human society. Rules, regulations, self-discipline
Green – Nature’s utilities. If you look at a patch of green, there are so many processes that we simply cannot see. There has to be an ecological nexus within the building to the landscape. This model can be used as a checklist looking at any piece of architecture.
Can you give an example?
If you apply the checklist to the Dong Tang Eco City – a fantastic feat of engineering, exhibiting incredible eco technology, we see how there are some water management systems in place.
However, there are several very clever human systems but there is no green infrastructure – there are patches of green, green squares, green roofs, but it does not link together and it certainly does not link to the landscape. Without the green infrastructure it’s simply great engineering and thus can’t be called a green city.
What about current checklists, such as BREEAM?
Box ticking for BREEAM ratings is all about micro systems, little sub items rather than the big picture. There is a perception that if you comply with LEED Platinum, if you comply with BREEAM, then you are carbon neutral and your development is green – but this is not always the case.
What is the big picture?
Green design. It starts with looking at the climate, what I term bioclimatic design. Understanding the seasons is vital. High insulation is great for cold winters but not much use for hot summers. But if you design for the mid-seasons then spring and autumn could then be managed through natural ventilation.
If you don’t adopt this strategy then you’ll create problems that need to be rectified later. Just look back at the climatic data of your site. Study the site conditions. In principle what we should try and do is increase and recreate the vegetation and ecology of the site before human beings occupied the site.
What should the developer’s approach be?
There is a hierarchy, like any development. When we design a building, even before we start designing, three models must be in place. The first is the usual spatial-induced model.
I, or my client needs X square footage, X% retail, car parking for X – the usual design model that any architect will be supplied. If that’s not in place, there is no basis for design.
Once you have the areas of the building, then you look at the cost model – an assessment of the quality of the building that the client wants on the site. The cost model must be related to the investment model.
This equation will be played out until it balances and offers the profitability that is required. The third model is the green model. So the question asked must be with this design brief model, with this cost model, what is the level of green building that you can get with this?
Design brief model, cost model, green model then you head towards the apex and then you get the design.
I need a new skyscraper built in the City of London, can you help?
Obviously I’m simplifying but with a skycraper on a site in the City of London you look at the orientation of the building, where will it get the sun, the wind and the best views – this all affects how you shape the building.
What is critical with facades in temperate zones is the different approach to take in winter and summer, in winter you want to let in the sun, in the summer you want to keep it out.
In the mid-seasons it doesn’t matter so much. In the UK we’re 52 degrees latitude, so the sun tends to be south, but you do get sun throughout the year. You can either design a sunshade that is moveable or one that is optimal allowing for compromise.
Things are different in the tropics, the sun is almost exactly east and west, so for a third of day the sun is directly on top.
Then again it’s relatively easy to design in the tropics, as your only prerogative is to keep the sun out. Sunshading, low glass, internal blinds. But ideally blinds should be outside to reduce the glare, because once heat enters the building you’ll need a cooling system.
Are skyscrapers sustainable?
Skyscrapers are the most un-ecological of all building types, they cost a third more energy to produce, to build, operate and demolish. They exist because of high land value and urban growth.
With urban growth there are only three options, expand side ways, develop satellite cities or intensify development within the city limits.
Expanding sideways is not ideal because it makes huge demands on land, more often than not arable land and green belt. Satellite cities demand intensive travel and high-energy solutions to move people from city to satellite.
So most planners will opt for intensifying development. Unless we find an economical viable alternative it’s a building form that will be with us for a while.
My contention is that if we are building tall as a result of increased urbanisation then we should make them as humane as possible, as pleasurable to use and occupy and to be as green as possible.
I’m not pro skyscrapers, but if we have to have them, then let’s make them green. If we shy away from them, then other people will continue to build them as they are at present.
What are your plans for the future?
I was at a futurologist meeting in Houston, the prediction was that within 10-15 years, if a building doesn’t generate its own energy then it will not receive planning or building permits.
That’s interesting because it radically changes the whole approach to architectural design. Architectural schools will be in a state of shock. Most of what is taught in architectural schools today is based on aesthetics, architectural preconceptions and strategy that has nothing to do with energy.
The idea of a building as a power station is an interesting proposition, moving away from non-renewable sources.
Further information
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