Since its inception, the ongoing message from the Southern African Light Steel Frame Building Association (SASFA) has been that the light steel frame (LSF) construction method is suitable for all types of building, from residential to commercial and office buildings. The latest residential architectural masterpiece in the Xanadu Eco Park overlooking the Hartebeespoort Dam in the North West Province is a stunning vindication of this claim.
“The advantages of LSF building (LSFB) in terms of time of construction, energy efficiency and logistics, all resulting in bottom line savings, are sufficiently significant to make the method appropriate for residential developments from ‘affordable’ on to the most upmarket structures,” says SASFA director John Barnard.
He adds that any impression that LSF building is for temporary or lower cost developments only, is being wiped out by the rapidly growing number of high-end, aesthetic structures where LSFB is being utilised.
“The house at Xanadu, designed by AIF Design Architects, is an excellent example. This is a magnificent home and its complex design and aesthetic outcome were, by and large, made possible by light steel framing.
“Also, the overall sustainability of the building method is perfectly in tandem with the Xanadu environmental philosophy where, in their own words, ‘…each phase of the development is sensitive to the preservation of the areas precious wetland ecosystem’ and energy and general environmental matters are deemed to be of paramount importance,” Barnard says.
AIF’s Cobus du Plessis concurs, saying that not only did they want an appropriate aesthetic for the location but that the ongoing energy consumption of the house was a major priority.
“To this end we chose light steel framing for the construction above the surface bed and took it one step further by introducing a 100mm air gap in-between the outer and inner layer steel frames. This not only gave us the advantage of the air barrier, but also gave us the aesthetic advantage of 350mm thick walls,” says du Plessis. It also made installation of services easy – plumbing, electrical and the central vacuuming system.
He adds that the main challenges were the cost of construction and the long construction period, and in both cases light steel framing proved to be the best option as there were significant savings on the construction time and costs.
Du Plessis says that LSFB has an excellent future in the high-end property market. “There are several advantages from an architect’s point of view. Cost is reduced, speed of construction increased, insulation qualities and energy efficiencies incomparable and, importantly, the end product looks exactly like the CAD drawings – perfect corners, straight walls and excellent finishes all round.”
The Xanadu house consists of three levels – the lower level for basement and services, which required excavation into the mountain, and the two upper ‘living areas’. “Our main objective was to capitalize on the spectacular view over the dam. Fortunately, the client understood my vision in turning the house ‘up-side down’ from the conventional way, so we designed the house with the dining-room, kitchen and entertainment room on the second floor, leaving the bedrooms downstairs,” says du Plessis.
Lightweight steel represents 85% of the structure of the house and all of it – roof trusses and the wall and floor panels – were manufactured at the Innosteel Building Systems factory in Honeydew and transported to site. Innosteel MD and founder Len Lategan was very upbeat about the outcome of the Xanadu project. “The thick-wall design makes it very special and with the double-glazing gives it the best possible insulation. I would hazard to say that this is one of the best insulated houses ever built in South Africa.” says Lategan.
Barnard explains that LSFB is significantly more energy efficient than more traditional masonry construction methods – both with regard to “embodied energy” of the materials and components, as well as “operational energy” of the building over its design life. A recent research project carried out by the CSIR indicated that a LSF building will require about half the energy needed to heat and cool a masonry residential building to comfortable internal temperatures. If necessary, heating of the Xanadu house in winter will be supplied by underfloor heating from circulated hot water.
Like du Plessis, Lategan is also optimistic about the LSF industry in this country. “There is no doubt that the technology is here to stay ,” he says, “but it’s still in its development phase and there is still much work to be done to convince those with vested interests in old technologies to accept the wonderful advantages of LSFB.”
According to Lategan, there is a lot of scope for development by the component suppliers, to capitalize on the narrow tolerances and predictability offered by LSFB. For example, doors should be delivered to site fully fitted in frames – installing doors in their frames should be a simple ‘clip in’ procedure. While there are certain suppliers that make this possible, availability and distribution are limited at this stage. But we are getting there and in time LSFB will be a mainstream building method in South Africa,” says Lategan.
Barnard too is encouraging saying that as the market increasingly realises that LSFB can be used for a range of different applications and takes into account the considerable benefits of the building method, both practical and financial, perceptions about traditional building methods being the only viable alternatives for residential and commercial buildings are definitely being challenged. “There are more and more examples of striking, well insulated buildings that are being built with LSFB,” Barnard says.
He adds that projects like the Xanadu house are helping to break the belief that quality
Structures have to be built in their entirety using heavy masonry or reinforced concrete. “There is no
doubt that the prejudices in South Africa against non-traditional building methods such as LSFB are
on the wane and the more people see such quality structures being built, and realise the
environmental benefits, the more they are opening up to these new methods of construction”, he
Andries Bezuidenhout, executive director of the Xanadu residential project, has an emotional stake
in the development as his grandfather, the legendary Bezuidenhout of Bez Valley in Johannesburg,
purchased Xanadu farm way back in 1942.
“For me the development of Xanadu Eco Park goes beyond just the continuation of our family legacy,
I am passionate about creating a lifestyle where people and nature can co-exist in perfect harmony,”
SASFA, formed in 2006, is a division of the Southern African Institute of Steel Construction (SAISC).