A new way to build houses

USING by-products of mining and manufacturing, a group of South African companies has devised a more cost and time efficient way of easing the affordable housing backlog.Read More
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Using by-products of mining and manufacturing, a group of South African companies has devised a more cost and time efficient way of easing the affordable housing backlog.
JOBURG’S flagship mixed income settlement, Cosmo City, in the northwest, has been chosen as a launch pad for a pilot project of affordable houses made from mining and manufacturing by-products.

Green house: Most houses in Cosmo City use solar power for domestic useGreen house: Most houses in Cosmo City use solar power for domestic useThe houses, which cost between R300 000 and R450 000, are built using fine ash from Sasol’s waste products in the coalfields of Secunda, which is mixed with cement to form a rich foam held together by a polymeric binder, instead of the conventional brick and mortar.

“The entire foamed mixture is encased in a steel frame structure and this comprises a panel that can be used for any fit-for-purpose building application,” says Marcel Hunt, a business analyst at Sasol ChemCity.

Walls and roof of the house, which is 85m2 in size, are made of steel and take about five days to assemble, bringing about significant savings in construction costs and energy use, she explains.

The housing project is sponsored by First National Bank and chemical company Sasol, and the technology used is developed by Tower Technologies, a subsidiary of EnviroServ Waste Management.

Technology
Hunt says the bank and chemical company joined forces to pioneer this technology in an attempt to ease the backlog in the affordable housing market, and to seek accredited alternative technologies to build affordable homes. The affordable housing backlog in South Africa numbers 2,5 million.

So far, about seven houses have been built countrywide using this method: three in Cosmo City which have already been sold and about four in Polokwane. Hunt says more than 50 orders have already been made and there are about 120 on the waiting list.

This technology is not new, she adds, but for it to flourish a fully dedicated factory would have to be built to manufacture the pre-built panels from waste streams, fly ash, gypsum and the fine ash cement. Fly ash is a by-product of Sasol’s energy production and gypsum is a by-product of industries such as paper making, fertiliser production and desalination of acid mine water.

“Until a factory can be built for the manufacture of these panels no form contracts can be put in place,” she says.

Cosmo city is growing rapidlyCosmo city is growing rapidlyThe managing director of Sasol ChemCity, Bridgitte Backman, adds: “Taking this innovation from idea to market has been particularly rewarding.”

Jobs
By supporting the development of this technology, Sasol aims to not only create jobs but also reduce its environmental footprint, she says. “A number of entrepreneurs and private institutions are additionally starting to explore the affordable housing space, identifying it as a market that is ripe with potential.”

Marius Marais, the chief executive of FNB Housing Finance, says this method was considered because conventional building methods are becoming increasingly expensive and directly affect the ability of banks and developers to meet the need for affordable human settlements.

“Because of this and continued increases in labour costs, we have been compelled to consider alternative technologies that will enable us to deliver affordable quality houses to the emerging middle class,” he notes.

Hunt explains that the steel panels used to make the walls can be used in any housing application. “Various factories can be set up according [to the] acquisition of a licence to manufacture and this can be rolled out nationally,” she says.

One factory producing four houses will have the potential to create about 96 permanent jobs.

The technology has provided bondable houses that are 10 to 20 percent cheaper than conventional houses but still deliver on quality and meet all building accreditation criteria of the South African Bureau of Standards (SABS) and the National Home Builders Registration Council, Hunt says.

Cement
Distinguishing factors between this method and conventional building is that this technology uses 25 tons less cement; the houses are thermally superior; they are monolithic; they are similar in look and feel to brick and mortar, with added benefits of quick delivery in building times; and panels equivalent to four 62m2 houses can be easily transported to site.

The new building system is cheaper than conventional building systemsThe new building system is cheaper than conventional building systemsMike Symons, the chief executive of Tower Technologies, says this building system has many superior attributes in that the walls are guaranteed straight, are solid and are incombustible.

“The panels are factory manufactured to ensure consistent quality and render an 80 percent weight saving to conventional building methods, which makes it logistically efficient. The panels are manufactured from waste streams and therefore ensure a low carbon footprint, and have been fully SABS tested and Agrément certified.”

He says this building system ensures a cost saving of between 10 and 30 percent compared to conventional building systems, depending on locality. It is also being licensed to prospective manufacturers countrywide.

Factory
Hunt says that because the panels are made in a factory, quality control is easier, adding that the housing structures have passed the same strength tests as conventional brick and mortar, and performed better under SABS testing than brick and mortar.

Rivash Panday, the waste management support team manager at Sasol ChemCity, says plumbing and electrical pipes are fitted into the steel panels and a separate constructor builds the foundation using conventional methods.

“Once the foundation has been laid it takes a day to put up all the panels. On the second day we put up the roof structure and on the third day we apply the plaster. So in about a month the whole structure is ready as opposed to the three months one would have to wait for a conventional house.”

Panday says that for this technology to fully thrive, funding is needed to establish a factory where all building materials can be manufactured at once.

FNB’s Carol Nkosi, who markets and sells the technology, has bought one of the three properties in Cosmo City. She says they are fully ventilated and comfortable.

Since going on to the market, Nkosi says, there has been a stream of requests and applications. Most keen buyers are between the ages of 35 and 45, are mostly second home buyers, and earn between R15 000 and R50 000 a month.