Construction World October 2015

Alternative building methods

LSFB – the most sustainable construction method around?

John Barnard, director of the Southern African Light Steel Frame Building Association.

“It is clear that sustainability is today a fundamental design requirement across the board in construction,” says John Barnard director of the Southern African Light Steel Frame Building Association (SASFA). According to Barnard sustainability with regard to buildings is essentially based on three criteria: social acceptability, affordability and energy efficiency. He claims that Light Steel Frame Building (LSFB) for low rise structures – and increasingly for multi- level structures – rates highly on most or all of the sustainability considerations: • Light steel frame buildings appear no different to ‘conventionally’ built structures, except that the quality of finishes is typically better with the former. It has found rapidly growing acceptance for ‘affordable’ as well as up-market buildings in South Africa. • It is a cost-effective building method, with financial savings emanating mainly from significant time savings to complete building projects, less rework, reduced logistical costs –which are of growing importance due to the escalation of fuel prices and general construction inflation – and a drastic reduction of rubble on building sites, when compared with the brick-and-mortar alternative. • Light steel frame building is significantly more energy efficient than heavy construction methods – both with regard to ‘embodied energy’ of the materials and components, as well as ‘operational energy’ relating to heating and cooling of the building over its design life. Embodied energy Barnard says that embodied energy of materials and ‘Sustainability’, ‘energy efficiency’, ‘green building’ and ‘carbon footprint’, are words that were not so long ago regarded as ‘things for the future’ in the construction industry. Well, the future has arrived.

components used for LSFB is reported to constitute some 20% of the total energy consumption of a 200 m² house, over a 50 year period, the other 80% being the operational energy. “While the embodied energy of the high strength galvanised steel sheet – used for the light steel frame – is significantly higher per kg than masonry building materials, a significantly lower mass of steel is used per unit area of building, rendering LSF wall assemblies superior in this regard – based on Australian research, double brick walls contain more than four times the embodied energy per square metre when compared with a LSF building. He adds that the low mass of light steel frame buildings offers another advantage – logistics. “The walls of a 200 m 2 brick built house will have a mass of some 178 tons including clay bricks, mortar and plaster, compared with the 10,2 tons of an identically sized light steel frame building. The cost savings in transport is obvious, but with another benefit to all road users – a huge reduction in heavy transport traffic on the national roads. Also, says Barnard, LSFB structures are insulated to specification pertaining to each climatic zone in SA, according to the new SANS 204, they have been found to offer significant saving in electricity used for heating and cooling, when compared with a brick building. Clients in agreement Many blue-chip companies agree, including both Burger King and McDonalds. Charl van Zyl, CEO of Silverline Group, who are building LSFB outlets for both of these iconic companies says that the fast-food chains are using LSFB because they support sustainable building methods as far as design, energy efficiency and the optimal use of natural light is concerned and because, by using LSFB, material wastage can be reduced by up to 30%, transport costs by 80% and the carbon footprint significantly reduced. “On top of this, the construction period required is significantly less than with traditional building methods, allowing the franchise to be trading that much quicker,” Van Zyl says. Meanwhile LSFB as a building method continues to grow rapidly not only in South Africa but also in the entire SADC region. “SASFA is receiving an increasing number of enquiries from neighbouring countries and has now signed up members in Namibia and Zambia, and is in contact with several other countries in the region. Overall the LSFB market is growing significantly and indications are that this trend will continue into the future,” Barnard concludes. ∞

The entire turnkey project of the Norwood Burger King took an incredibly short 12 weeks to complete.

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