Eco-homes
Last updated: September 19, 2008.
Most of us take a pride in where we
live and look after our homes.
Earth is our home too, but you'd never know it from the way we treat
it: the planet is under ever-increasing pressure from the things we do.
Each day, there are more people trying to survive on the world's limited
resources—by turning farmland into factories, burning down forests,
pumping out oil, and belching pollution into the air. If you care about
the planet, there are lots of small things you can do that will make
a small difference: you can recycle your trash or
swap your gas guzzler for an
electric car. But if you want to make a
really big difference, you have
to make a much bigger change in the way you live. One way you can
do this is to swap your cold and drafty, energy-guzzling house for a
lean, green eco-home powered by renewable energy.
Let's take a closer look at eco-homes and how they work!
Photo: This typical eco-home in Westminster,
Colorado is built from wood (a sustainable, local material), has huge windows to
absorb sunlight, and makes power with solar cells on the roof.
Photo by John Avenson
courtesy of US
Department of Energy/National Renewable Energy Laboratory (DOE/NREL).
Where to build eco-homes
If you're trying to show a bit of respect for the planet, the last
thing you want to do is build a big, brash, shiny new home. Instead,
you want your eco-home to blend into its surroundings the way a moth
camouflages itself against the bark of a tree. Some of the most
striking eco-homes are earth-sheltered houses. Instead of being made
of brick or concrete and standing
proud above ground, they squat
modestly against earth banks or they're constucted substantially
underground. That
not only helps them blend unobtrusively into the landscape, it also
provides warmth and shelter, reduces the need for
heating, and saves energy.
Photo: This earth-sheltered in Minneapolis,
Minnesota is set into the ground.
Photo by Pamm McFadden courtesy of US
Department of Energy/National Renewable Energy Laboratory (DOE/NREL).
Eco-materials for eco-homes
Building a house uses a huge quantity of raw materials. From the
bricks that make up the walls and the timbers that support the floors
to the electricity cables and pipes
that run in between them, a house is
consuming a significant amount of Earth's raw materials. One of the
most effective ways to reduce the environmental
impact of a new home is
to use recycled materials instead of
brand new ones. It's relatively
easy to find recycled timbers to make floors, for example, and recycled
glass made from old glass bottles is also fairly easy to come by. You
might be surprised just how many recycled products there are and how
much fun you can have trying to place them in your home! Did you know
that you can get chairs made out of recycled bicycles,
wallpaper made
from recycled office paper, and kitchen crockery woven from recycled
telephone cables? You can buy a lot of nearly new things from eBay and
save a fortune, as well as help to save the planet. Most places have
local community recycling schemes and salvage yards nearby. It costs
you nothing to explore these places and you might be surprised by what
you find.
It's seldom possible to make a new home from entirely recycled
materials. Where you need to use new materials, you can try to source
them locally. That
will help reduce the cost of transporting materials to the
construction site (and the energy wasted in the process), but it also
helps a new home to blend in with the local architecture. If you use local artisans and workers to
build your home, you're also helping to put money into the local community and the local
economy. Thinking globally and acting locally is an important part of
saving the planet.
Saving energy in an eco-home
Most homes consume colossal amounts of energy,
mainly for heating in
the winter, air-conditioning in the summer, and supplying hot water for
our baths and showers. We use smaller (but still significant) amounts
of
energy for
powering domestic appliances such as washing
machines, dishwashers,
televisions, and computers. (Generally speaking,
appliances that get hot when you use them are the most inefficient:
they waste quite a bit of the power they take onboard making that heat.)
Photo: You can reduce the energy losses from a
home by squirting the walls full of foam insulation, which you then
then simply cut and smooth to fit. This home is insulated with Icynene,
a plastic insulation
material similar to that used in pillows and mattresses.
Photo by Paul Norton courtesy of US
Department of Energy/National Renewable Energy Laboratory (DOE/NREL).
Eco-homes try to tackle the problem of energy use in two different
ways. First, they are designed so they need less heating and
air-conditioning. Many eco-homes have
large areas of glass on walls that face the
sun for much of the day. By
absorbing as much sunlight and heat as possible (a technique called
passive solar gain), eco-homes
can reduce the need for electric, oil,
or gas heating.
Most eco-homes also have very large amounts of
insulation (dense, air-filled
padding stuffed into the walls and
ceiling spaces) to reduce heat losses to the atmosphere. While many
traditional buildings (especially old-fashioned offices) need
air-conditioning in the summer months, eco-homes are generally designed
to use natural ventilation. As
well as having opening
windows, some of them are designed in an egg or spiral shape so that
air
naturally sucks in through the bottom and spirals up and out through
the top to keep the building cool.
Photo: Huge glass windows, oriented to face the
sun, heat
this home effectively through passive solar gain.
Photo by Chris Gunn courtesy of US
Department of Energy/National Renewable Energy Laboratory (DOE/NREL).
No matter how well-designed and insulated, an eco-home still needs
energy to power appliances. But there's absolutely no reason why this
power has to be transported huge distances from an enormous power
plant, wasting vast amounts of energy in the process. (Did you know
that two thirds of the energy a power plant makes is lost either in the
plant itself or on the journey to your home? What a waste!) Every
building in the world has the potential to make a significant
proportion of its own power. In sunny climates, solar panels on the
roof can be used to heat water (known as passive
solar or solar thermal energy) or to generate electricity (known as active
solar or solar electric energy). In windy
countries, how about a small micro-wind turbine mounted on the roof or
positioned in a corner of the
garden? Spinning away silently as the breeze blows past, it could be
cutting your energy bills and helping to save the planet. Most
eco-homes come to an arrangement with the local power companies so that
any extra energy they generate beyond what they actually use can be
sold back to the power grid, earning them money!
Photo: The electricity meter in this eco-home
is designed to run either forward or backward.
When the solar panels on the roof are generating more electricity than
the house needs, the extra feeds into the local grid and helps power
other people's homes. It can be very satisfying to watch your
electricity meter running in reverse!
Photo by John Avenson courtesy of US
Department of Energy/National Renewable Energy Laboratory (DOE/NREL).
Saving water in eco-homes
Most of the world's water is used for such things as agriculture and
industry, but our homes also use a great deal as well. Every time you
flush the toilet, brush your teeth, or fill the kettle to make a cup of
coffee, you're using water—but you also using energy, because it
takes energy to make water clean and pure enough to drink. We can all
reduce the water that we use in simple ways like switching the tap off
when we brush our teeth or buying "intelligent"
washing machines that
get our clothes cleaner with less water. These things all make a
difference. But if you're building an eco home, you'll want to go one
step further by installing a greywater system. This is effectively a
large tank in your house or your garden that stores some of the water
you've used for reuse before it returns to the sewage system. Water
from your washing machine and shower is probably still clean
when you've used it, so instead of draining into the ground, it flows
into the greywater storage tank instead. This, in turn, can flush your toilet and water
your garden. (Think about it: why
flush your toilet with crystal clear drinking water that's been
super-cleaned and purified? It's just absurd!)
Talking of toilets, they waste a huge volume of water. In many
countries there are now laws requiring new toilets to have a dull-flush
system, which lets people choose either a small or a large amount of
water when flushing. Again, some eco-homes go one stage further by
having
composting toilets. These do
away with water altogether. Instead of
flushing into the sewage system, the waste drops through into a
container underneath the house where it is safely turned into compost
(an earth-like material) that can be used on the garden to help grow
your plants. Composting toilets might not sound very nice, but they
don't smell and they really work! And there's
nothing better for the environment than "closing the loop": turning
your waste back into something useful.
What's so good about eco-homes?
If you're happy with your life and you love your big car and your
flashy home, that's great—maybe you've worked very hard but these
things and you want to enjoy them. But not everyone on the planet
enjoys the same standard of living as you: Earth simply isn't big
enough for all of us to live in luxury. And things are going to get
worse. With pollution and global warming
causing ever-increasing concern, with the world's population rising,
oil gradually running out and mounting concerns over where our energy
will come from in the future, doesn't it make sense to try to live a
little bit more
sensibly? It might sound harsh and austere, but living in an eco home
isn't really any different—and it's one
way you can make a real difference to the planet.
Photo: Eco-living is more comfortable than you
might think.
This eco-home in Penrose, Colorado looks no different from normal, but
uses
half the energy of a typical house. The large windows and thick
concrete walls absorb heat, keep out the cold, and reduce the need
for both heating and air-conditioning.
A home like this costs only 10 percent more to construct than a
traditional home and soon pays for itself in the energy it saves.
Photo by Dwight Stone courtesy of US
Department of Energy/National Renewable Energy Laboratory (DOE/NREL).
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