He who sustains
Editor of Green Home magazine and CEO of alive2green, a media company promoting sustainability through design, Gordon Brown illuminates the colour of building's.
'Green' can be used to describe any number of very different approaches to buildings. A straw-bale house for instance is a green building but someone who has placed photovoltaic panels on top of a conventional building will also claim to have a green building, and each has a case. The problem comes in when someone makes only superficial changes and then markets the house as a green building. This is called green washing and undermines the return on investments made by those who are doing things properly.
To think of green building in terms of expensive or cheap oversimplifies the issue. One has to differentiate between various green building interventions: some save money, some cost nothing and, yes, some do cost money. The reality is that the initial investment in the building is greater by five to 10 percent, according to experts, part of which can be recouped from operational savings and part of which is simply the premium you pay for a better product. The goal is to achieve Pareto's 80/20 principle of green building which states that 80 percent of the environmental gains can be achieved with 20 percent of the premium.
Passive design remains the least-cost, highest-impact intervention available, assuming you are using an architect, which we recommend doing. This will facilitate a truly green building that will significantly improve the quality of life for those who live in it by ensuring that it will remain cool when the weather is hot and warm when cold.
The meaning of green becomes quite clear when applying for certification under the Green Star certification run by the Green Building Council of South Africa (gbcsa.org.za). Although its system is geared more to developers than homeowners, the principles can nevertheless be applied and the Green Building Council invites people to follow the tool. It is an excellent method of ensuring that you will actually end up with a green building, even if it's not certified as such.
It is most certainly possible to ‘green’ an existing structure. This is known as retrofitting and there are multiple interventions one can look at. In the home, water, heating and lighting are the big energy consumers. Replacing your geyser with a solar water heater or heat pump is very effective, as are making use of LED light bulbs and installing low-flow showerheads.
Before spending a lot of money on major retrofit interventions, one should consult an expert who can perform an audit of the building to ascertain what can be done and what the direct benefits would be. It is important to be clear about why you are retrofitting. Is it to improve energy efficiency and/or improve the indoor environmental quality affecting human comfort factors such as temperature, brightness and air quality… or do you want be greener generally?
For a new build, the fundamental green principles I would prescribe include orientation of the house to the north and the use of shading to protect against direct sun on the northern and western elevations. Plan fenestration or windows so as to maximise natural light and minimise direct sunlight. Install a solar water heater or heat pump instead of a geyser and capture rainwater via a harvesting system and tank.
Green Home magazine greenhomemagazine.co.za