It
takes more than a roof filled with solar
collectors and pv
panels to make a
green energy house.
Although harvesting the sun's energy is one aspect of green
energy buildings there
are other things to consider. For one thing not all houses are compatible with solar applications. Things like site location, roof orientation and insulation are also important. Retrofitting
an existing home with energy efficient solar applications is always a possibility, but the best time to plan an energy independent house is before it’s built. Besides the solar factors and the insulation factors and the design
factors we should also use green materials to reduce the carbon footprint.
What is a green material?
Thought you’d never ask. Green materials are local materials that are in plentiful
supply OR recycled materials that would otherwise be in landfills. Let’s take a look at some
houses that use green construction materials.
Adobe
Houses are made from the
desert clay upon which they are built. This type of house would not be suitable
in a cold damp climate in the northern part of the US, but in a south west area
like New Mexico adobe houses are ideal. With little money and a lot of hard work
it's possible to build a beautiful energy efficient house made from mud
bricks . The mud bricks are reinforced with straw to hold them together. These
materials are in plentiful supply and locally available. Since there's an
ample supply of sunlight in New Mexico the adobe walls gather solar heat during
the day and release it gradually at night. This is an example of direct gain
solar heating that moderates the temperature extremes found in desert areas. A
few solar collectors or perhaps a small supplemental heating system may be needed
to get some people through the cold New
Mexican nights, but most of the heating requirements for this adobe home involve
passive solar heat gain.
This adobe house has been stuccoed with cement. To hold cement in place chicken wire is bonded to
the outside of the house and pulled tight. The scratch coat is then covered with
a thin layer of pink flavored cement to give that finished look.
Cordwood
Construction is an excellent
option for people living in cold a northern climate with an ample supply of
trees. The R value of a log 12" log is higher than a 4" wall
packed with insulation and a little insulation is placed on top of
the logs to prevent conduction through the cement.
This is a simple example of cord
wood construction. The cord wood replaces cement blocks that would be used
in a more conventional construction. BUT the advantage of using logs has to do
with the insulating value of the wood and also the low cost.
Exterior siding and interior
insulation covered with drywall are not part of cord wood construction. Once the logs are cemented in
place between a frame the wall is finished.
Notice this log end home uses
nine foot long logs for the corner frame of the house. It could just as well
have been framed in 6x6 posts.
Strawbale
Constructionis another alternative for people who live in Nebraska and all the
other states that have a plentiful supply of straw. Straw bale houses have an extremely
high R value and once stuccoed with cement and plaster they take on a
comfortable grandeur of their own..
This unfinished house may not look very
attractive BUT once it's finished the heating
bill for this little North Dakota dwelling will put ma serious dent in the
heating bill.
Notice Styrofoam insulation has
been bonded to the outside of the foundation wall. Without this insulation heat conservation
would be imposible..
The Styrofoam must be protected in
the same way that the straw is protected. This is done by first wrapping the entire house
with chicken wire before applying cement. This Ferro Cement application
combines the tinsel strength of steel with the compression strength of concrete.
Earth Shelters
combine the
green technologies of adobe construction, cord wood construction and straw bale
construction. The hobbits who lived in the Shier lived in earth shelters. J. R.
R. Tolkien has been an inspiration for many green people motivated to make an intimate
connection with the earth and mother nature.,
Simple caves were the original earth
dwellings. Over time evolving technologies led to the construction of customized
caves now called earth shelters. Today earth shelter construction is a rare
especially in the U.S.A. During
the 1973 Oil Crisis, there was a back-to-the-land movement, and a renewed
interest in earth shelters and underground home construction. In the
70's many frustrated college students became interested in this: back to the
land, self
sufficient, sustainable lifestyle. Unfortunately, earth shelter construction
never became very popular and has been viewed by architects, engineers, and the public
as unconventional. Natural earth shelter materials and methods are not common knowledge, and much of society still remains unaware of the
benefits.
Using the earth's, thermal mass
to moderate temperature as well as offer protection from the harsh extremes of
climate are a few benefits. Other advantages of earth dwelling include energy savings, privacy, efficient use of
land, low maintenance and sustainability.
A
more conventional Solar Houseuses more conventional building materials but
this kind of dwelling is still considered a green energy home because it
makes efficient use of renewable construction materials such as lumber and
cellulose insulation. Remember the essential features of a green energy home minimize the carbon
footprint. Roofing material that would normally be used to frame an attic are
used to create additional living space with a steep south facing wall. This
south roof/wall maximizes sunlight exposure with minimum materials. Notice the South roof is lined with a full array of collectors. Some engineers
say this is too much. BUT in a cold climate an energy independent house needs a
lot of heat and a lot of insulation. If the roof were not lined with collectors
the second floor would overheat so these collectors actually prevent the roof from
overheating in summer. If the heated water is stored in a well insulated heat
storage vault unwanted heat would never be a problem.
The solar greenhouse provide
additional heat for the house in winter and also provides a space to keep plants
alive all year long. Just imagine what it would be like to pick a Cherry Tomato
in January when your front lawn is covered with snow.
.jpg)
It
takes more than a roof filled with solar
collectors and pv
panels to make a
green energy house.
Although harvesting the sun's energy is one aspect of green
energy buildings there
are other things to consider. For one thing not all houses are compatible with solar applications. Things like site location, roof orientation and insulation are also important. Retrofitting
an existing home with energy efficient solar applications is always a possibility, but the best time to plan an energy independent house is before it’s built. Besides the solar factors and the insulation factors and the design
factors we should also use green materials to reduce the carbon footprint. 
