Charles Neil, Landmark CEO, discusses green buildings.
Landmark Properties CEO Charles Neil discusses the results of a study assessing the feasibility of green buildings.
Can you explain the benefits of retrofitting?
Typically in a house you could reduce energy consumption by 70 percent through proper cladding, triple glasing, and so on. You can do these things after a house has been built, even the cladding.
Retrofitting is about insulation, the way your house your A/C units - how the air circulates in a building. You can also put permafrost in the ducting, because you get a lot of energy loss in the ducting.
While there is coating around it, if you coat the inside with an insulation package as well, you reduce the loss. There is a lot of energy loss between the chiller and the outlet.
What else can be done to make a building greener?
The positioning of a building can save you energy. The Index Building here in the DIFC in Dubai, for example, has been positioned differently, you can see it slightly sticks out.
They’ve positioned it for the sun, so the sun doesn’t eat into the windows, it hits the side of the building, which is clad and insulated.
What can be achieved in terms of water conservation?
Green buildings could do a huge amount. Retrofitting is quite expensive for buildings, because you would need double piping. With wastewater, you’d clean it up, you’d have a wastewater filtration plant in the basement, and it doesn’t have to be very big, and grey water is then used in the toilets.
But you need separate piping. So you can only do it when you are building a new building. But you can still do quite a lot. You can for instance do something called sewage mining. Its an Australian concept, and I’ve actually looked into it.
Typically what you could do for a development is take the wastewater that goes into the main sewage system back out of the sewer, clean it up and use it for cooling plants.
How feasible would sewage mining be here in the UAE?
For sewage mine you just need the permission of the municipality to mine the sewage. And the big district cooling providers like Empower, Tabreed, Emicool, would have to agree on a standard for the water that is to go into the cooling systems. They use fresh desalinated water now, which is a huge waste.
Please explain the potential that wastewater holds for district cooling?
A lot of water is wasted in district cooling, as they add chemicals to it. You can only circulate that water six to seven times before that water gets saturated with those chemicals, and you have to dispose it into the sewage.
If you instead use cleaned up wastewater, which can be cleaned up to 98 to 99 percent purity, you may not be able to use it six to seven times, maybe only four times. But the cost for desalinated water is huge.
I think for freshwater its about 18 dirham per cubic meter, for treated water it is only six dirham. So as you can see, there is a huge differential, and a huge potential for these master planned developments like the Burj Khalifa or the Dubai Investment and Financial Centre to start reusing that water, for cooling or for landscaping.
Are there other aspects to air conditioning that can be optimised?
Air conditioning units at the moment are very wasteful. They give up a lot of water because they release it when they compress air. That’s pure fresh water just going straight into the drains at the moment, which is not being used again. There is tremendous potential for savings there.
The technology to make buildings greener already exists and is used elsewhere. Why is it not being applied freely in the region?
The technologies are not new, and are pretty standard in places like Australia. There was a rush to build in Dubai in the period between 2004 and 2008, and no one really stopped to consider the environmental impact.
Now construction has slowed down, but they are committed to all of these buildings, so we’re going to have to wait for this construction cycle to end. But the next one will go off on a much more sustainable basis.
And this is what we would like to do. We would like to see regulation brought in for that. But what you could do immediately is retrofitting, which isn’t as efficient and cost more but you still get a return on investment. This is the data that we now want to start to research and publish.
So is current legislation not sufficient?
No, I think it has got to be more. We need more standards on insulation, the fitting out of AC units, recirculation of air in buildings. All new buildings should be double skinned. If you got a double skin you can circulate the air around the building, and this is where you get the energy saving benefits.