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undreds of architects from around the world attended the Union Internationale des Architectes international conference in Durban, South Africa, on Aug. 8. Participants voiced their commitments to developing ecological buildings that efficiently use nonrenewable natural resources through the sustainable use of energy. The Jakarta Post'€™s Sebastian Partogi talked with Marco Kusumawijaya, an architect and director of the Ruang Jakarta Center for Urban Studies, about the issue and its challenges in the context of Jakarta.

Question: What is the best indicator for determining whether a building is ecological or not?

Answer: Through its utilization of energy. To be ecological, a building needs to minimize its utilization of energy from unrenewable resources. Ideally, buildings need to be able to generate their own energy from solar, wind or biogas power. However, it will take some time before they can develop such technologies. Currently, most buildings still use energy from unrenewable resources like oil, coal and diesel to power electricity. That'€™s why they have to minimize their consumption of energy to prevent the resources from depleting.

What is the biggest challenge related to energy utilization in Jakarta'€™s office buildings?

While office buildings in countries with cold climates dedicate most of their energy utilization to creating room heater systems, those in tropical climates dedicate energy utilization to keeping rooms cool with air conditioning. Therefore, the utilization of energy for air conditioners should be our focus when it comes to a discussion of ecological buildings in the context of Jakarta. As long as a building uses air conditioners, it can'€™t be categorized as ecological because air conditioners use a lot of energy, constituting approximately 30 percent of a building'€™s total use of electricity.

But without air conditioning, won'€™t we feel uncomfortable because it will be too hot.

Actually, there are several alternative methods we can use to keep our buildings cool without using air conditioners. Just apply this principle of physics: to reduce heat, you need to reduce room humidity and increase air circulation using ventilation systems. You need to allow the wind to enter the building horizontally through windows and vertically through gaps in the roof. This will reduce heat significantly.

Furthermore, when you use air conditioning you have to completely seal your building to allow for efficient cooling. Unfortunately, while this method effectively prevents heat from outside from entering the building, it prevents the heat emitted by human bodies from getting outside the building and the heat will eventually accumulate and remain. So insulating buildings with thick glass is not a good solution to maintaining the temperature.

If you want to minimize the impact of outside heat to your building, its better build trees around your building. Trees can reduce heat from the sunlight by three to five degrees Celsius. So let'€™s say the temperature outside is 33 degrees, if you plant trees around your building, the temperature will be reduced to about 28 degrees, which is quite comfortable.

Unfortunately, these methods for maintaining temperatures cannot be applied to Jakarta'€™s office buildings, most of which are skyscrapers.

Why is it that these methods cannot be implemented in skyscrapers?

We need to go back to the principles of physics. The taller the building, the more difficult it is to control humidity, because the wind moves faster in higher altitudes. High altitudes also make proper circulation and ventilation difficult. Furthermore, tall buildings can'€™t be sheltered by trees, obviously. This is why our office buildings still depend on air conditioning. But again, we need to question whether tall buildings are really necessary for office space.

Why do you think tall buildings are unneccesary?

Actually, tall office buildings are built not because Jakarta has a lack of space for office buildings. If you really look at it, tall buildings are concentrated in only a few areas of Jakarta, most notably in the central business districts of Sudirman, Thamrin and Kuningan. It is the strategy of capitalism: by creating these small but highly exclusive areas and branding them as strategic, land prices will be much more expensive than in others.

Furthermore, an office building should contain a maximum of three to four stories. At that height, proper air ventilation and circulation is still possible. The buildings can also be sheltered by trees which will reduce the heat that comes from outside. Furthermore, tall buildings use an inefficient amount of energy to power their elevators and pump their waters.

Look at Barcelona; most office buildings there are an average of six stories high. But they use their space efficiently. So in order to achieve ecological buildings, we should not cluster our office buildings into exclusive central business districts, which forces us to build tall, inefficient buildings.

How can the development of ecological buildings still be made possible in Jakarta?

Currently, the cost of constructing ecological buildings is still expensive due to simple economics logic: because the buildings are not popular yet, there is limited demand, resulting in a small supply, leading to high prices. This is why the government needs to give incentives to businesses committed to ecological buildings; for example, by providing them with certain tax breaks for running their businesses in an environmentally sustainable way. Or, it can work the other way around, with the government imposing taxes on businesses that do not consider ecological concerns in running their operations. In the Netherlands the government imposes this kind of ecological tax, which operates in a similar way.

Aside from the tax incentives, what other benefits can businesspeople receive for developing and committing to using ecological buildings?

Their costs related to energy, most notably electricity, will be much lower in the long run. Furthermore, they can obviously use it as a method of branding, like '€œuse my products because I run my business in a sustainable way.'€ In my own view, the global business is moving in that direction, so if we [Jakartans] don'€™t follow suit, we will soon be left behind.