12 Nov 2009
The concept was developed by the Council for Scientific and Industrial Research (CSIR) and a demonstration model on the CSIR premises was unveiled. The Department of Science and Technology supports the project.
The 40sqm houses will be built using concrete blocks and mortar, while a CSIR technology developed for roads will be adapted to form the foundation slabs of the houses.
"Using innovative design and construction technology, CSIR researchers have developed a concept with significant improved performance and sustainability. If built according to CSIR specifications, and on large scale, such houses will be constructed much faster and at similar costs than when using conventional methods," says Dr Sibusiso Sibisi, CSIR president and CEO.
Llewellyn van Wyk, senior researcher at the CSIR, describes the building method "as a modular, design-to-fit approach similar to a Lego set where pieces fit together". "There is no wastage as a set number of blocks is used in every house and the design is standard.
"Standard low-income houses have no ceilings and thus no insulation, which results in wild variations in temperatures. The thermal performance of the roof was improved dramatically with the addition of an insulation material that doubles up as a ceiling.
"The houses face in the right direction to ensure that bedrooms benefit from sunlight, while the living room faces north. We want to build houses and not just structures," Van Wyk says.
He says the houses will have single-skin walls that consist of concrete blocks that are 144 mm wide. "With conventional clay-brick methods, two bricks are required to build a wall this thick."
He says the added advantage of concrete blocks is that they can be cast on site and quickly laid. The major drawback is that they offer poorer insulation. "We are, however, working on a new concrete block model which will eliminate the problem of weaker insulation to a large extent. This model will be launched by March next year."
"The houses in coastal areas will also get a thermal coat to help with moisture penetration."
He says the idea for the foundations was conceived because some contractors in the low-income market lay sub-standard foundations. "Local labour can be used to construct such foundations, which is based on ultra-thin, continuously reinforced concrete technology," says Hans Ittmann, executive director of CSIR Built Environment.
Van Wyk says this research project is a work-in-progress. "The most recent additions include a solar-powered geyser on top of the roof and photo-voltaic panel above the front door for powering lights inside the house.
"We are also working to launch the second model during the course of next year. It will consist of hybrid technologies which consist of light steel frame materials and concrete blocks."
Van Wyk admits a low-cost house built with conventional materials such as clay brick is less expensive. "They are about 6% cheaper, but the automation factor will be the big cost equaliser between the two methods when the concrete block houses are built in bulk."
"There are also some extras that can be added onto the concrete block houses, but they will increase the costs up to 12% on conventional methods. These include things such as thermally-insulated plaster and solar water heaters."
Van Wyk says the concept will soon be presented to Tokyo Sexwale, minister of human settlements, who will then decide whether it should be introduced to parliament for approval. "We currently have a project underway in Mdantsane in the Eastern Cape where 2003 houses will be built over the next 12 to 18 months. The Western Cape provincial government is also interested in implementing this technology.
"We are hopeful that non-governmental organisations (NGOs), housing foundations and more provincial governments will get on board once we get parliamentary approval," he concludes. – Eugene Brink
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I like innovation and find the article interesting. I am involved in low cost housing.
The real challenge is not to build the houses faster. You just add resources by doing that.
The only viable method to decrease the cost of houses (as traditional built is demanded by communities) is to look at mass housing solutions (staple housing) such as China an Brazil has done.
The real challenges for contractors is cash flow. Government departments can not keep up with inspections and payments-should thy pay contractors regularly delivery will speed up.
Secondly, the availability of materials such as traditional concrete in rural areas is a huge challenge. – Anonymous
This article talks about technology that is imho not advanced. The big pro blem with block / brick building has been the variability in the construction result dependent on the (skilled / unskilled / cheap) labour.
Manufacture in controlled environments, and transportation to site, or on-site controlled manufacture, are technologies that HAVE NOT been properly explored.
Google "Moladi" and look at what a Eastern Cape company has created. VERY good ideas, unused by the authorities.
There is another continuous casting machine called the "finnbuilder". Allows very strong construction in predictable outcomes at reduced prices. Doesn't get mentioned anywhere.There is also the possibility of surface-gunnited panels using insulating foam cores – that have been used for housing in areas where climates can be extreme. The panels are manufactured in a controlled environment and then transported to site.
What about Eskom buying a solar-heating manufacturing plant, and then supplying these at vastly reduced prices (no duty, transport, admin etc) to the housing industry? We have a need for MILLIONS of these things.
We are not using our kops to solve the housing crisis. We are doing solutions in a donkey way – limiting ourselves to the only way we have been doing it in the past - in my humble opinion. – Mark Feldman
I stay in Hanover Park / Western Cape. I think it is a very good idea. It is becoming increasing difficult for the low income people to buy a property. I just think of myself married with 2 kids. We stay in a Wendy house, simply because can't afford to buy a house. Apart from that I think this is a very good idea. If this project should start in the Western Cape please inform. So that people like us can apply. – Reilly Meyer
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