SUMMIT PLACE The Assupol Building, the 11-storey winning office block in the Summit Place development
This year’s annual Steel Awards, hosted by the Southern African Institute of Steel Construction, showed excellent growth for the South African light steel frame building (LSFB) industry, with more than 25 000 m2 represented in category entries.
The awards, which took place on September 13, saw 19 projects entered into the LSFB category by seven leading Southern African Light Steel Frame Building Association (Sasfa) members from around the country. The majority of the project entries came from Gauteng, KwaZulu-Natal, the Free State and the Eastern Cape, making up 75% of entries. The rest of the entries came from the remainder of the provinces.
Sasfa director John Barnard says, while the quantum of entries is an indicator of how the industry is fairing, the floor area covered by the entries is a measure of how the industry has transformed since LSFB first became a category in the Steel Awards ten years ago. Barnard says it reflects the trend towards larger projects being built using light steel frames.
This year, LSFB entries comprised 30% residential buildings, 30% community buildings, with the remaining 40% of LSFB used in office or commercial and industrial projects.
“It is pleasing to see the growth in LSFB use in the residential sector. Homeowners have accepted that this method of building is no different to ‘conventionally’ built structures, and that the quality of finishes is typically better,” Barnard explains.
He adds that homeowners have realised that LSFB 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, owing to the escalation of fuel prices and general construction inflation – and a drastic reduction of rubble on building sites, compared with the brick-and-mortar alternative.
When analysing the LSFB entries for this year’s Steel Awards during the judging process, Barnard notes how it was interesting that different entries represented different attributes of LSFB, with logistics playing an important role in the more remote projects, low mass being important in the construction of long-span roof trusses, while speed of construction was key for most other entries.
2017 Steel Awards LSFB Winners
There were two joint winners in the MiTek LSFB category at the Steel Awards – Global Learning Academy (GLA) School Hall and Summit Place.
Summit Place, located in Garsfontein, Pretoria, already has several two- and three- storey office buildings successfully clad with LSF façade walls with external thermal insulation composite systems (ETICS). Sandton-based architects Boogertman & Partners decided to use the same solution on the Assupol Building – the 11-storey winning office block – in the same development.
In most of the earlier Summit Place buildings, the architect specified slanting, gravity- defying façade walls. With the Assupol Building, however, the architect decided to introduce elegantly curved façade walls, which were made possible by using LSF.
The Assupol Building is the first and highest South African high-rise office building where façade walls were constructed with LSF and ETICS external cladding. Insulation product manufacturer Saint-Gobains’ ETICS was used for the external cladding, as it is most suited to curves, provides a durable external finish, and insulates the office building to reduce the energy required for heating and cooling over the lifetime of the building.
Barnard says this project amply portrays the benefits of LSFB.
“The façade walls were built quickly and accurately with, for example, all of the 700 pre-made external windows fitting perfectly into the predesigned openings in the wall panels. The low mass of the LSF and ETICS cladding eased logistics, and made handling on-site easier, requiring only a small team of artisans to do the installation. “Also, importantly in these circumstances, the low waste factor meant a small operational footprint, allowing other trades to work in tandem,” Barnard explains.
“This project is aesthetically pleasing and uniquely captures most of the benefits of LSFB,” he says.
The GLA School Hall project, based in Jeffrey’s Bay, had the challenge of establishing a world-class green education facility on a tight budget. This required architect Jacobus Scott to come up with innovative solutions, especially because the owners wanted a multi-use gathering area, which required a long-span roof design.
“The MiTek Ultra-Span system was perfect in these circumstances. The MiTek team designed and installed a cost- effective solution that not only looks impressive, but also effectively solved design and engineering problems that could never have been overcome with a traditional roofing system,” Barnard explains.
He adds that what stood out about this project was how closely the final structure of the building resembled the original sketch drawing used to promote the solution. “This is not the lowest mass-per-area roof structure, but some clever design captured benefits made possible by high-strength, low-mass steel trusses. Natural ventilation, optimisation of natural light, photovoltaic cells and rainwater harvesting, and the recyclability of LSF materials used, made this green structure possible.”
Barnard concludes by noting that, while these two are worthy winners, all entries were of an exceptional standard, and reflected the quality and excellence of an industry that is becoming increasingly relevant in a construction environment that is facing rising costs in materials and transport, and in an end-user environment where energy costs are soaring and environmental issues are paramount.