The world is switching on to sustainability; and building homes that are durable, save energy, reduce waste and promote wellbeing.
Built to last
Global warming, greenhouse gases, endangered species… these phrases can no longer be ignored. The harm we have done and continue to do to our planet is being highlighted by everyone from politicians to screen stars. If you want to do your bit for conservation, there’s no better place to start than at home.
Until recently, it was only hardy ‘eco-warriors’ who would even have considered environmentally sound building practices. But worldwide, more people are realizing that sustainable development only makes sense. So more people are building homes with natural materials, installing solar panels, and opting for an ecologically sound way of life. It’s become even easier to do so, as there are more eco-friendly building materials now available than ever before. And more architects, engineers, and builders are using design and construction techniques developed in response to environmental concerns.
Dr. Johnny Anderton of Eternally Solar, a company specializing in the development and management of integrated, sustainable projects, says there are various alternative building methods, ‘most of which are likely to be more environmentally friendly than the use of concrete blocks, mortar, and bricks.’ There are greater advantages too: homes that are constructed to suit their location and climate enjoy natural thermal comfort – and construction and maintenance costs are generally lower too.
What is sustainable development?
Sustainable development refers to the process of fulfillment of human needs while maintaining the quality of the natural environment and can be categorized as environmental sustainability, economic sustainability, and social-political sustainability.
Timber construction allows for a range of design solutions to achieve an environmentally friendly result. Timber houses can range in appearance from ultramodern to traditional weatherboard homes. The advantage of timber construction is that it requires less site disruption than most. Timber is a renewable resource that actually counters carbon emissions (carbon that enters the atmosphere as a result of burning carbon-based fuels, chiefly coal, oil, and natural gas). However, transport and manufacturing processes can add to the overall carbon cost associated with timber construction. The sun’s trajectory differs with the seasons. Calculated overhangs on this home allow for more sun to enter it in winter, and less in summer.
Better building practices
Eco-friendly building involves construction that’s not harmful – and sometimes even beneficial – to the environment. It’s often referred to as green building. The concept originated in the ’70s, in response to the growing energy crisis and environmental concerns. Eco-friendly construction is not only more efficient in its use of local or renewable materials, but it also takes into account the energy that goes into creating those materials – including how far they have to be transported, as the energy required to transport materials also produces hazardous emissions. So it goes without saying that green buildings are generally more thoughtfully positioned, designed, built, renovated and operated. The raw earthiness of these structures is calming and the walls have a thickness that simply embraces you.
Straw bale homes
Straw bales were first used for building more than a century ago. Straw bale walls are often laid on concrete footings, adding to the intrinsic energy cost of their construction. A renewable material, straw can be grown, harvested and grown again. Greenhouse gas emissions associated with straw bales is very low. One ton of concrete requires more than fifty times more energy in its manufacturing than straw. Straw-bale walls have excellent insulation characteristics. To maintain a straw-bale building’s overall performance, it’s essential to insulate roofs and windows.
The final appearance of rendered straw bales can be very smooth and almost indistinguishable from rendered brickwork. You can, however, make it more expressive and textural. Straw bales rate highly for buildability because the building can be straightforward and well-suited to the workshop- and volunteer-based building programmes.
Sandbag homes are extremely economical. The Eco Beam with sandbags system is a patented, SABS approved construction method. An Eco Beam-framed building uses about a third of the timber used in a standard wood-framed building. The sandbags are placed in the Eco Beam framework then plastered smooth. One can also use fiber cement planks or plywood planking – which are more environmentally friendly – as exterior cladding.
There are hardly any disadvantages to this style of construction: it’s inexpensive, offers superb thermal comfort and the building material, sand, can be sourced on site. It can also be built with minimal skills and no on-site electricity. This process also requires minimal site clearance and is fire resistant and waterproof. This technique is inexpensive, as most building materials can be sourced on site. Minimal skills are needed and it requires no on-site electricity.
The green element
Usage of non-toxic elements and diverse products in and around your home will improve the quality of indoor air. But even if your home is not built on ecologically sound principles, you can still incorporate conservation into your lifestyle – especially with regards the use of energy.
Cement is one of the most energy-intensive products to manufacture and is the origin of vast amounts of global carbon dioxide emissions,’ says Dr. Anderton. not only is the average cost of cement on the increase, factor in the ‘carbon cost’ and the price of manufacturing it escalates further. So it only makes sense to opt for any one of a large number of alternative building methods, which minimize the use of cement. Renewable energy is proven technology; the price is dropping, the rest of the world is going that way, that’s where our investment should be going as well.’
The most cost-effective way of using solar energy is to heat water directly. A medium solar system (for water heating) could be installed With expected electricity savings annually, you can pay back this system within three years, says Dr. Johnny Anderton of Eternally Solar. After that period, your electricity will be ‘free’. Turning solar energy into electricity is still very expensive; to take an entire household off-grid (with a solar electric system) costs thousands – but the savings are well worth it.
Passive solar incorporates the sun’s orientation into the home’s design and is a great way of saving energy in heating and cooling: north-facing windows allow as much natural light into the house as possible, for instance. Also, a window with an awning that receives direct sun all day in winter will not do so in summer as the sun is higher in the sky. Some other common-sense ideas include using specific types of trees on the property: deciduous trees to the south of the house will be lush and leafy in the summer – helping to block out the hot sun – and bare in winter – letting rays through to warm things up.
By heating high mass areas of a house, such as the floors or walls, spaces are heated by surfaces instead of the other way around. Insulating your roof is one of the easiest and most economical ways to cut down on your need for heating and cooling.
Led-new technology lighting
‘If we all converted our home-, office- and sign lights to LED, and used the wind or solar energy to power these lights, it would go a long way to resolving South Africa’s energy crises,’ says Richard Lomax of LEDs shine. The bulbs we currently use require large amounts of energy to generate light because they heat a filament to produce light, UV, and heat. LEDs (light emitting diodes) are efficient because they generate light by using small amounts of electricity to excite electrons in a complex chemical reaction that produces only visible light. Energy savings are in the region of 20 to 50 times that you use with incandescent bulbs. This means that wind and solar power become viable options for generating light in the home all year round. One thousand LED Christmas light bulbs can be run off a small 3KW wind turbine. Combining this with solar technology is the ideal. Apart from supplying energy to the national grid during daylight hours, the system is self-sufficient at night, as long as there’s wind. The system pays for itself within two years from the energy saved.
Here are a few other ways to do your bit in the fight against global warming:
Save water by installing grey-water systems, low-flow showerheads, and tap aerators, use a ‘hippo’ in your toilet cisterns, and ensure pipes running from geysers to taps are short.
- Hang your washing on a clothesline instead of using a tumble dryer.
- Mow the lawn with a manual push mower instead of a petrol- or electricity-powered one.
- Switch to biodegradable cleaning products or do as our grans did: use common household ingredients like vinegar as cleaning aids.
- 5 Cover your pots and pans while cooking – and match the pot size to the element you’re cooking on. Thoroughly thaw frozen food and allow hot food to cool completely before refrigerating.
- Only switch your dishwasher on when you have a full load – this will save energy and water.
- Buy energy-saving appliances – look for the energy saving logo.