sample essays of IELTS

13 Skyscrapers and Environment

In the late 1960's, many people in North America turned their attention
to environmental problems, and new steel-and-glass skyscrapers were
widely criticized. Ecologists pointed out that a cluster of tall
buildings in a city often overburdens public transportation and parking
lot capacities.

Skyscrapers are also lavish consumers, and wasters, of electric power.
In one recent year, the addition of 17 million square feet of skyscraper
office space in New York City raised the peak daily demand for
electricity by 120, 000 kilowatts-enough to supply the entire city of
Albany, New York, for a day.

Glass-walled skyscrapers can be especially wasteful. The heat loss (or
gain)through a wall of half-inch plate glass is more than ten times that
through a typical masonry wall filled with insulation board. To lessen
the strain on heating and air-conditioning equipment, builders of
skyscrapers have begun to use double-glazed panels of glass, and
reflective glasses coated with silver or gold mirror films that reduce
glare as well as heat gain. However, mirror-walled skyscrapers raise the
temperature of the surrounding air and affect neighboring buildings.

Skyscrapers put a severe strain on a city's sanitation facilities, too.
If fully occupied, the two World Trade Center towers in New York City
would alone generate 2.25 million gallons of raw sewage each year-as
much as a city the size of Stanford, Connecticut , which has a
population of more than 109, 000.