Atch’s Weblog

Do you water your lawn with tap water? Do you brush your teeth while in the shower? Do you wash your car every weekend? Do you leave a bottle of water at the restaurant knowing that it is not yet empty? If your answers to these questions are ‘yes’, maybe you don’t realize that half of the world population will soon fight for clean water as the climate change and global warming will lead to water shortage. It is inevitable to talk about it now.

For centuries, Bangkok has been known as the ‘City of Water’ or ‘Venice of the East’. The altitude of Bangkok is just about 2-3 meters high above sea level, and September flooding seems to be more troublesome than do the summer draught. Thai people once used small boats as an effective mode of transportation. Of course, stories about civilization of the nation cannot be told without mentioning about Chaophraya River. This is expressed in the way Thai people built their homes in the past. Traditional Thai houses have elevated terraces and living spaces to avoid flooding. ‘Loi Kratong’ and ‘Songkran’ are very well-known festivals for foreigners. So, without plentiful water, how could we have such terrific and fanciful cultural activities that are related to water?

Still, you may not fully understand why Thailand; the country located in the tropical region where the rainy season lasts many months; needs to be concerned with water conservation. We have plenty of water and many times more than enough. The idea that water is fully renewable might be true until recently that good-quality water is scarce in almost everywhere on the planet. Having enough water doesn’t mean we can pollute it freely. Treating natural water into the level that is drinkable for human is, in some ways, not suitable for the environment, if we consider ‘chlorine’ as an alien to the natural water body. To make the matter worse, the more we use treated water, the more we discharge wastewater to the natural environment. And do you know how much foreign chemicals from bathrooms, garages, kitchens, and laundry machines we put in our wastewater? So here you understand that physically, water is renewable, but ‘natural’ water which is a vital part of the ecosystem is not!!. Once you pollute the water, you pollute the ecosystem too. There is no way to bring back natural water; no matter how hard the authority is trying to enforce the quality of discharged water in terms of the maximum BOD (i.e., Biochemical Oxygen Demand) level.  As I used to say, the mother earth has reached her full capacity of cleaning our dirtiness, and wastewater treatment is one of her hard duties.

You may wonder what you can do to ‘green’ your home in terms of water conservation. There are a number of approaches. Firstly, use less water in any kinds of activities in your home. Secondly, recycle it! Thirdly, use alternative sources of water. Lastly, treat it well before discharging it to the city sewers. To use less water in your bathroom, there are plentiful models of water-conserving toilets and low-flow faucets and showerheads. The Thai Environment Institute (TEI) even has an eco-labeling system for water-conserving products known as “Thai Green Label” (http://www.tei.or.th/greenlabel). The faucet which meets the Green Label standards must have the water flow rate not exceeding 6.0 liters per minute. For a water-closet, a single flush toilet must use 6.0 liters or less of water per flushing cycle.

It is not difficult to find those Green Label products in the market. However, you may find that some of them do not look appealing at the first place. Many luxurious toilets and faucets do not have water-conserving features and that is why you do not find such products being used in grade-A residences and hotels. This needs some motivations for the public to be more responsible to the environment and for the product developers to be more concerned with their design criteria.

For your gardens, to save water is to understand how your plants need water. If you choose local plants for the landscape, you will find that the plants will survive easily in this climate without having to spend too much water to feed them. Again, some people prefer foreign plants since it looks more extraordinary than the plants you see locally everyday. Apart from proper selection of plants, you might consider using ‘drip-irrigation’ for your landscape. The system works very efficiently by slow feeding water to your plants throughout the day. This way, you can avoid losing water to evaporation and runoff.

There are hundreds of ideas on how to save water in your home either in your bathroom or in your garden, which I can not cover them all in this article. We will discuss later about them, but here at least we should be aware that water conservation plays a big part in green buildings. And that important part should not be missed.

ผศ.ดร. อรรจน์ เศรษฐบุตร

Asst. Professor Dr. Atch Sreshthaputra

Faculty of Architecture, Chulalongkorn University

Chairman of Green Building Program. The Association of Siamese Architects.

Since the economic boom in Thailand in the mid 1990s, we have witnessed a major change in contemporary Thai architecture; particularly for high-rise buildings in Bangkok. One of the changes is apparently found in glass-facade corporate buildings. Glass is now used for cladding all exterior walls of high-rise; not only for windows in our homes any more. If we look into the history of glass-facade buildings, we will understand that the idea of using glass facades is originated from the need for daylight and environmental control in cold-climate regions like America and Europe; not for year-round hot-humid climate in countries like Thailand. Something must be really wrong that cold-climate countries like Germany and U.S.A. are exporting more and more glasses to hot-humid countries to build their buildings, whilst the vernacular architecture in these regions are properly designed to protect solar heat as much as possible. Just looking at the traditional Thai houses, both windows and exterior walls are well protected from sunlight in order that the interiors are kept cool. It is considered as an innovative, local intelligence that our ancestors have developed for hundreds of years.

The same intelligence is found in the glass facades used in cold climates. The designers of vernacular architecture in those regions have developed an innovative material that has a superb performance in terms of trapping solar heat to warm the interiors.  Sunlight transmitted through the glass turns into heat and is trapped inside. This is the same effect we are familiar with when we park our cars in the sun. Apparently, it is what we must avoid for hot climates. So, what has given the way for glass façades to come into this country, and who is to be blamed for that? It is the ‘modernization’ that imports architecture from developed countries in cold climates to everywhere on the planet. The term ‘Regionalism’ was almost replaced with ‘Internationalism’ for the country to compete in the globalization arena.

Now, things have already gone too far for us to say ‘no’ to glass façades. So, what we can do is to control the use of glass façades to the optimum by means of building codes. By law, when architects design buildings, they must calculate the amount of heat transfer through envelopes and try not to exceed 45 Watt/sq.m. This has seemed to be a sound measure to save energy in buildings before they are built. Unfortunately, many architects are not well trained to do such a scientific calculation; not to mention about government officials who do not have enough knowledge to check and approve the calculation sheets. This law is now ineffective; leaving us no way to control energy consumptions in new buildings. Then, the modernization goes on and new buildings are consuming more and more ‘make-it-cheap’ energy. There is no doubt why a new glass-façade, high-rise building just appeared in New York is later appeared in Bangkok skyline within a couple of years!!!

Even though, the law has gone, at least it has led us to understand that glass façades are bad for warm climates if we take into considerations of energy and environment. Clear glass is the first thing to avoid for use as glass façades in this climate. Not only does it let in too much solar heat, it also generates glare that the occupants cannot tolerate. This gives a way for tinted glasses, which allow less heat and sunlight. If you look at Bangkok skyline, you will see colorful glass facades; some are blue, some are grey, and some are green.  Possibly, this might be about fashion, but scientifically, it has been tested that green-tinted glass performs better than do the other colored glasses in terms of energy efficiency. That is why many people in construction industry say that green glass is ‘green’ because it saves energy. New housing developments use green glasses instead of clear glasses for windows and claim that the projects are energy saving and then ‘green’. Of course, glass manufacturers produce more green glasses as the public thinks that green glass saves energy.  Sale representatives of housing projects keep telling their customers that their projects are greener than other because of green glasses. Is it that simple?!

Before the public is misled by all advertisements, I must say that green glass is not necessarily ‘green’. Green glass saves energy only when it is compared with clear glass, but having full-height green glass windows (from floor to ceiling) like what in New York will not help you save on energy bills at all. In stead, having a large area of glass is not visually comfortable as too much glare will force you to put on curtains at most of the time. Interior curtains help screen strong sunlight, but the heat already gets inside through the glass. Eventually, no matter what color your glass is, if the windows are not properly designed at the first place to take account on hot-humid climate of Bangkok, you will never really save energy. There are a lot to discuss about using green glass that really save energy, and how a full-height glass façade can be ‘green’.

ผศ.ดร.อรรจน์ เศรษฐบุตร

Asst. Professor Dr. Atch Sreshthaputra

Faculty of Architecture, Chulalongkorn University

Chairman of Green Building Program. The Association of Siamese Architects.