If you ever wanted to save electricity and improve the comfort of
your home without using any high-tech gadgets, then passive solar
design is the answer.

Passive solar design is a technique of using the
sun to naturally heat and light up your home or office. This is
achieved by using various building features and materials to improve
heating and cooling efficiency. The best part about passive solar
design is that it is relatively simple to implement, little maintenance
is needed, and your home’s market value can increase considerably.

Your home’s passive solar potential is determined by where and how
it is situated and by the types of windows and materials used. Although
most buildings can be optimized to receive the ideal amount of
sunshine, it is easier if they are on flat land or a sun-facing slope.
If your home is surrounded by many trees, make sure they are deciduous
so that they shade your home in summer, but their bare branches let
sunlight through in winter. Also, try avoid nearby buildings that
create too much shade.

When constructing a new home, make sure it is built so that the
length of the house faces the sun, allowing the maximum amount of
sunlight. Also note how the size, shape and placement of windows will
determine the amount of natural heat and light in your home.

So how does the sun heat your home? There are three ways:

To ensure the most natural heat from the above three sources, a
number of large windows should be placed on the sun-facing side of your
home, allowing maximum sunlight in.

All that sunlight and heat in your home is useless, if it cannot be
stored and used when the sun is set. The solution is to use
heat-absorbent flooring and walls that carry on radiating heat long
into the night. A simple way to reduce power cost in winter is to
locate to rooms in your house that get the most sunshine at certain
times of day.  Also, shady rooms should be cut-off (their doors closed)
from the rest of the house to retain heat better.

During summer, the right length roof overhangs or eaves can be used
to control the amount sunlight and heat in your home.   The eaves
should be wide enough shade out the intense midday sun, but let the let
low-angle sunlight through during dusk and dawn to light up and warm
the home.  Again, the right trees and shrubs can be planted to regulate
the house’s seasonal exposure to the sun.

For current buildings, the simplest passive solar design solution is
to replace your windows with modern ones, that use various methods to
store up 50% more heat. Although they are 10% to 15% more expensive,
they pay for themselves in the long-term from all the power saved to
heat your home.

Double-glazed or Low-emissivity (Low-E) windows let solar heat in,
but keep in the indoor radiant heat. Another way to reduce heat loss is
to ensure tight seals around all windows or by using multiple panes
that have gaps between them filled with argon or krypton gas.

What your windows are made from can make a big difference too. While
metal framed windows generally conduct heat out the house, wood, vinyl
and fiberglass frames insulate the heat better.  Always ensure any
modern windows bought have labels issued by Energy Star or the National
Fenestration Rating Council.  These labels provide statistics on how
effective and efficient the windows are at retaining heat, which helps
you purchase the right windows for your conditions and budget.

So you can see, passive solar design is the effective use of nature
and physics to maximize the use of the sun’s natural lighting and
heat.  Always remember, the point of solar passive design is to reduce
your electricity usage and bills. So it is recommended to always weigh
up the costs against the potential power savings when installing any
passive solar solution at home.