At a time of a worldwide ecological disaster, the phrase "green is beautiful" has a double meaning: not just one's color preference, but also the need to lead an ecological life style in tune with the environment. That includes construction and the houses we live in. Up to a 15 years ago no one took environmental control and protection seriously; it was considered the domain of a few freaks. But now the world is taking the problems of ecological devastation very seriously, having been rudely awakened from the illusion that one can abuse the environment without endangering the delicate balance between man and nature. The realization that our planet is sick and is endangering humanity came slowly, but nature was constantly sending danger warning signs: holes in the ozone layer; the gradual destruction of rain forests, which produce much of the oxygen we breathe; the pollution of drinking water; the gradual growth of deserts, especially in Africa; the pollution of seas and especially rivers; global warming and the drying up of lakes and inland seas. The Aral Sea in Central Asia once covered an area of 68,000 square kilometers. It is now barely a 10th of its former size because the rivers that fed its waters were diverted to irrigate cotton fields. But why go so far; the same has happened here. Israel once had three inland lakes: the Hula, the Kinneret and the Dead Sea. The Hula dried up in the 1960s, the Dead Sea is in the process of drying up and now contains less than half the water it had 50 years, while the Kinneret is constantly losing water. The historic Jordan River is nothing more than a sewer, as are most of the country's rivers. Being ecologically sensitive means we should live in a way that does not harm the environment. We should adapt our buildings and life styles to the needs of nature to prevent harming the environment. This new trend is called ecological construction, or green building. Building green If there is anything that changes the physical face of the earth it is buildings. The Indians of the Amazon or the natives of Borneo live in houses that fit in with the environment, but not so the residents of London, New York or Tel Aviv. The Manhattan skyline is not part of the natural environment; even a five-story building is not. But people must live somewhere, and in crowded cities the most practical way to meet the rising requirements of a growing population is by going skyward. So the only way to alleviate the impact of these monster buildings on the environment is to build green, including: a construction process that is as clean as possible; maximum use of recycled products; use of materials that are as less harmful to the environment. Green building is gathering momentum and many companies are developing new technologies and new techniques. Among them are the Gilad and Enat construction company and the Green Build construction company. "We have developed new building techniques that are environmentally friendly: the construction process is relatively clean and tidy, the materials used are environmentally friendly, and the construction time is approximately half of what it would take to build conventionally," Pini Gal, general manager of Green Build, recently told The Jerusalem Post. Green building is still largely undefined, but according to the guidelines of the Environmental Protection Ministry, a green building uses recycled raw materials, makes maximum use of breezes and solar energy for heating and cooling, and is equipped with filters to deal effectively with kitchen fumes, among other things. A green apartment building will be less "ecological" than a single family building. The technology to make a skyscraper as ecological as a single-family home is still unavailable, but single-family homes can be very ecological. They can produce their own electricity, collect their own rainwater and store it in underground tanks, recycle used water and incinerate waste. There are now green neighborhoods. In northwest Kfar Saba, opposite northeast Ra'anana, the Kfar Saba Municipality has earmarked an area of some 560 dunams as a green neighborhood. A green neighborhood has green houses, a high percentage of green spaces, a garbage-collection system that separates waste according to recycling usages, a low noise level and ensures a high quality of life. Building green is much more expensive, but ultimately it will be less expensive. Israel is a small country that is densely populated. If the environment is left unprotected, it will be costly.