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Section 2 Architectural Planning
There are many ways to incorporate solar
energy into the design of a home. Probably the
best-known example is a solar water heater.
Solar energy can be used in many other ways,
however, using both active and passive tech-
niques. With careful design, a solar water heater
can also power radiant fl oor heating. Because
heat rises, this is an effi cient use of a renewable
energy source.
An example of a completely renewable
solar energy system is a passive solar heating
and cooling system. This type of system should
be planned for early during the design of the
home. This enables the materials for the roof,
walls, fl ooring, and windows to be selected spe-
cifi cally to work with the passive system. The
only requirements are a south-facing exposure,
the proper materials to allow the sun to enter
(glass or plastic), and the proper materials to
absorb and store the heat or cold for future use.
The materials used in passive solar heating and
cooling systems vary according to the tempera-
tures in the region in which the house is built.
Passive solar systems may or may not meet
a home’s total energy needs. Most homes that
incorporate passive systems also have a tradi-
tional system as a backup. However, combin-
ing a passive solar system with other energy-
saving techniques (such as placing windows to
catch breezes) can greatly decrease the home’s
need for nonrenewable energy.
Geothermal Energy
Energy from heat within the Earth is known
as geothermal energy. With the use of a geother-
mal heat pump, a home can be designed to use
the Earth’s heat for both heating and cooling.
See Figure 11-11. Some systems also supply the
house with hot water, eliminating the need for
a separate water heater.
Unlike passive solar systems, which cost
almost nothing as long as they are designed
into the house, geothermal heat pumps are
expensive. They are very reliable, however, and
in most cases, they pay for themselves within 5
to 10 years.
Energy-Effi cient Design
Another principle used in designing a net
zero building is to reduce the energy require-
ments of the home. Passive solar heating and
cooling help accomplish this, but other tools
are used as well. For example, sophisticated air
barriers and “super insulating” insulation keep
conditioned air from leaking to the outside, and
prevent bacteria, toxins, and other unwanted
chemicals from entering the home.
A related method is weatherization, which
helps prevent air from leaking around win-
dows and doors. Weatherization techniques
include low-cost processes such as caulking
around windows and installing weatherstrip-
ping around doors. See Figure 11-12. Storm
doors and storm windows are also considered
forms of weatherization.
Another design technique that can lower
energy costs is daylighting. Daylighting means
using windows and skylights to provide natu-
ral sunlight for the home. Light from the sun is
free and reduces the need to run electric lights.
When you design the house and the rooms it
will contain, place windows and skylights to
bring natural light into the home.
Figure 11-11. A horizontal closed-loop geothermal
system like this one is a good choice for a new
home. The trenches for the system need to be
only four or fi ve feet deep, which helps keep costs
down. (Slavo Valigursky/Shutterstock.com)