Monthly Archives: November 2015

The criteria was set out in Singapore that the energy that was used in gardens by the bays was not more than that of a conventional Singapore office block.

We had to get precise humidity conditions and temperature variation differences. The entropy [Humidity]  in the air [of singapore] is very high. From the outset the concern was a way of reducing the humidity in the air and the solution was to use liquid  desiccant  to dry the air.  If we just cooled down the hot air at high humidity it would be very difficult to handle.  So this is why we pass the air through the liquid desiccant [lithium chloride], a drying system.  Our issue is what do you do with this liquid again. When you have these pads with liquid desiccant running down them, the volume of air on these pads increase so you have a weaker solution of desiccant at the bottom which is ‘ Runny’ rather than concentrated desiccant.  A solution to concentrate the desiccant once more is to boil it. Our initial design was to use solar energy so you would have a concentrated desiccant store and a weak desiccant store. So when Singapore is sunny the solar panels would heat up the weak desiccant and the steam would leave via the super trees.

Solar energy in Singapore you get a long period of when its cloud , particularly when the smog from Indonesia obscures the sun for weeks at a time.  When we worked out how much desiccant that we needed to filter the air, there was not enough constant solar energy to be had in order to re concentrate it. We also found out that when the sun eventually comes out you get a sudden surge in energy which could potentially boil the desiccant. The Solution to this was to make most of the 2 year pruning of Singapore and also wooden packing waste from the harbour nearby. With this waste it could be use a constant fuel to concentrate the desiccant and drive the chillers  (11 articulated lorries worth of pruning wood). The boiler used for this project cost millions of dollars.

The Eden project was always cost conscious, that is why all their air handling units sit outside. It is not a sophisticated design in terms of environmentally engineered.  Blow in air and see what happens. The difference in terms of plants rooms and services is that we very strategic when it came to the placement and concealment of the units, whereas on our visit to Eden it was evident that they placed the units wherever it fell. We had a big injection of money from the government which allowed us to concentrate on the best solutions such as these .

Singapore regulations do allow you to have glass roofs. we had to have waivers for the project to be allowed to build it. We had to use our carbon energy from the waste system argument in order to obtain these waivers

our studies showed that there was only the need for the solar shading 8% of the annual hours of the year but in reality they are deployed very rarely due to the fact the glass is not cleaned as often as we had hoped.

the competition design was a structure with big set of fins with the glass hanging off. We imagined that the fins would offer the shading. In  fact the shading would be too much. So we looked at hollowing out the structure with a truss arrangement with an open mesh, but that obscured to much light. So then we finally looked at a grid shell structure which is quit week by lateral forces. So the primary arches are used to prop up the grid shell so it doesn’t fall over.  It becomes a very skinny structure so that we you are inside there is not a lot of structure in the way of the glass.

Both Biomes are self shaded on the north side due to their form. It is down to  where the sun sits in the sky. The specially selected glass that was used actually deflects light at certain angles. Also typically sun at a high angle of incident of glass a lot of the light is reflected including radiation.

When looking at the operative temperature of the building we were concerned of 80% for the plants 20% for the people.  1100 watts of sunlight in Singapore. Inside you have around 330 watts of sunshine. If you are standing still in sunlight you feel uncomfortable. The programme of the building makes you move through the space and so evaporative evaporation happens and keeps you cool. So there are no complaints in the building.

Our studies have shown that the plants in both of the biomes do not mind being a bit cooler. We had to move some diffusers away from some of the plants as they sometimes mistake it for winter and go into hibernation, but they have managed to keep both of the biomes flourishing and operative at 22C which is less that we want but it is much more comforting for the visitors. Obviously this additional cooling would be a problem if you had to pay for the electricity but when it comes from the waste that was going to be incinerated away, they don’t really mind.

We did quite a bit of research on ETFE. The main thing that we looked at was the ability to coat ETFE with a selective coating. We wanted to let in as much light in but restrict the amount of heat. The manufacturers of ETFE said they could coat the ETFE, but we were concerned that the coating could be scratch of with the movement of the wind etc. With the glass having the selective coating on the inside of the panes it was safer. Another reason was that aesthetically it didn’t look right with the form . And thirdly Singapore is known for heavy rain and the noise inside would be very worrying. With glass its quite exciting but with ETFE it would be very loud. The final reason is the client wanted the project to feel like permanent piece of architecture and believed ETFE doesn’t look permanent.

The Alpine house was designed to be natural ventilated however this building was not designed to be naturally ventilated. It is not stack ventilation as such. The height helps with the stratification of the air but the height overall comes through the height which is needed for the parabolic arches for the area and also is taken from the aesthetic design of Wilkinson Eyre.

From the very start I wanted the building to use displacement ventilation. We were very Keen not to have ducts running up height. When we first ran the CFD models we found that the temperature we were getting high up at mountain level was uncomfortable. This was when we putting air in at lower and middle level.

One issue we had with ventilation was to get air to the flower garden which sits in the cool flower conservatories. There is limited amount of air cooling, just around the perimeters. So they added more diffusers so it keeps it cool. We also suggesting they should buy fans on wheels to blow at trees during the night time. trees are stressed in nature during the wind and spread roots to compensate. we had issues with kew where trees just fell over because they didnt have many strong roots.


The site for the gardens by the bay was in Singapore. Was there any initial concerns that came to mind in regards to the programme of the building and location.  Temperature , humidity etc?

one of your previous collaboration with Wilkinson Eyre was on the Alpine house at Kew, which uses the idea of stack ventilation. You also mention that the form of the Eden project, the geodesic dome inspired gardens by the bay. How did these two project influence the form of the building.

how important was achieving the correct lux levels inside the biomes, and how did the Eden project help you achieve this.

What was the average interior lux levels when on the overcast day.

9% of the annual hours the shading devices are deployed. would you class this a compromise to the design due to the temperamental weather of Singapore

you mention in your book that you considered using ETFE In the scheme. What kind of analysis was involved in the research of the material.

you describe that the flower dome is self shaded from the extreme sun angle. Could you explain this some more.

You mention that the early cfd studies for the cloud dome was an issue as the top of the mountain dome would be too hot, is this one of consequences of using a stack ventilation form?  Was the jet diffusers that were the solution to the problem inspired by the Arups solution at Eden.


“his remit was to be sustainable but the premise of the design was communicating mans relationship with plants so in terms of sustainability it is about waking up to how we relate to plants and how important they are for humanity. The design team was made up of like minded people so that issues that arose could be dealt effectively.

“like all projects  worldwide this was a commercial project. There were cost involved. The initial project design was for it to be twice the size of what Eden is now , consisting of 4 internal biomes and a 5th running across the perimeter, however this design got pulled back – this was because the client (Tim Smit) wanted something twice as big for half the price, (employing the likes of Grimshaw ) he believed they could achieve this. This is how the Biomes with the tri-hex-tri space frame was brought about by using a shape that maximised volume with little materials and little transportation cost   ”

“if you want to work on holistic sustainable design you have to align yourself with how nature works. Nature works with an evolution process so instead of fighting change you adapt. where a lot of use architects have a vision of how we think something should be at the beginning and try to hold on to it as much as possible, however this is not a sustainable design. So when it came to the design process, we have a lot of problems with nature conflicting with what we wanted to do. So we use this to manipulate our project ”

“the millennium fund on gave out money when they were presented with a water tight business plan. In order to get that you need to be at stage D (design development). For the design to be at this stage it needed to collaboration with the entire design team with Tim Smit. The problem was is that the client had no money to pay the design teams until the he receive the millennium funding. The additional challenge was that when the designs were going ahead the client did not own the land. The way around this was to buy little chunks of the land off of the miners and start building on that, however ongoing works as the mine meant the pit continuously changed and thus the design changed.

“due to the continuously changes it emerged that they need a flexible building that could be adjust on site to meet the ground”

“like pushing balls into the ground. Wherever they hit the ground that’s where they finish. if the ground changes you just subtract bits of the ball, but the ball doesn’t move. This way 80% of the building is always fixed.”

Legibility of a building is very important, there an advantage if a building can tell a story. Similar to medieval cathedrals where people were illiterate and could read bibles so the stories are in the buidling. For our age we should have building that are legible and in our case we wanted to convey how man relates the natural world. When you enter the visitors centre there is rammed earth. According to McAlpine , we wouldn’t be able to used rammed earth because it was too complicated so standard building material should be used. But if we talk about regeneration and bring back the history of an industrial waste land and using clay from the site, we manage to convince mcapline to do it.