6.10 Retrofit Existing Building Stock
6.10 Retrofit Existing Building Stock
Using the suggestions above when designing new houses can make a big difference in reducing the environmental impact of the construction industry. However, new buildings account
for a very small percentage of energy costs in developed countries. With this in mind, considerations must be
made to the existing housing stock, and what can be done to reduce the
environmental impact of these buildings.
Draft Proofing
Heat is lost through draughty windows and
other gaps in the building envelope.
Stopping these leaks will keep the heat inside the house and reduce the
energy needed to keep it warm.
Installing double glazing (or
secondary glazing) is one measure to achieve this, as windows are where the
greatest amount of heat is lost. However one must weigh up the insulation
benefits of the double glazing to the embodied energy and toxicity of UPVC
which is used to make the window frames.
Insulation
Heat is lost through solid walls. This can be reduced by adding insulation to the
existing walls. Internal insulation can
be mounted onto interior walls, but will reduce the overall space. External insulation is a possibility, where
insulating panels are mounted to external walls. In houses that have an inner and outer wall
in the building envelope, cavity wall insulation can be put in, which involves
pumping insulating material into the gaps between the two walls. Loft insulation prevents heat loss through
the roof. There are many government
schemes to encourage people to save energy by insulating their homes.
Heating System Upgrade
Often the most cost effective solution can be
to replace the heating system with an efficient boiler or thermostat, which
will reduce the gas used to heat the house by increasing heating efficiency.
Now watch the following 20 minute video about green buildings, which introduces more green building techniques such as green roofs, integrated PV windows, permeable paving, bamboo flooring, aerated concrete blocks, and insulation innovations
http://webpages.uidaho.edu/sustainability/chapters/ch04/ch04-p03.asp