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.

Many of the building in the UK were constructed during the Victorian period, during which architects employed successful methods for solid, long life buildings, but not with scarce energy resources or sustainability factors in mind. In fact, coal was the main energy source so many buildings were designed to be heated with a coal burner in each room. Also very little insulation was employed, as the plentiful supply of coal didn't require energy saving measures. As a result, many of these old building are under-insulated, and waste a huge amount of energy. Measures to reduce the impact of these old buildings are known as “retro-fitting” and are outlined below.


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.

The cost and embodied energy of retrofitting must be weighed in with cost and energy savings resulting in their implementation. Some argue that there is only so much that can be done with the existing housing stock, and a more successful tactic would be to knock them down and start again.

Many measures such as putting up thick curtains, turning down the thermostat and wearing warm jumpers can be employed by residents of domestic properties to reduce their houses energy use.


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