Rosebank Link

What is the purpose of the structure/project?

At 15 stories above the ground, the building consists of two basement parking levels, a ground floor or public/retail level, five parkade levels, and nine stories of offices from a podium level. It will allow everyday pedestrians to traverse without barriers from the Gautrain through to the adjacent malls.

What was the brief to the Architect?

As a building standing foremost in the center of a developing cosmopolitan area, the client wanted to have a unique building that served the needs of the client, its neighbors, as well as the public in a new, exciting, and smart way.

Was the project envisaged in steel from the start? If not, why was it built in steel in the end?

Yes, Meeting Pods, Atrium, and Media screen.

Meeting Pods:  The Meeting Pods can be viewed from the landscaped thoroughfare which forms part of the showpiece of the buildings. The architectural intent for the pods is to be as open as possible, embedded in the glass. These pods are also cantilevered from the concrete frame and was a retrofit.

Atrium:  The Atrium structure formed part of the glass façade, spanning over six stories, additionally it formed a part of the glass skylight structure on the Atrium roof. The structure spanned large distances and had to be as slender as possible while limiting deflection.

Media screen:  The LED panels required special connections at very particular points, while constrained by the removal time by the crane, steel allowed achieving these challenges.

Give a brief description of the structural framing. What type of sections were used (e.g. hollow, cellular, I-beams etc) and why?

Meeting pods:  Gravity loads were the main consideration; therefore, the loads were concentrated around one axis and normal I-section portals bolted to the concrete were the most efficient.

Atrium:  The inner–and bottom chord of the Atrium vertical truss and roof truss were determined by architectural constraints. The outer chord is braced by transom beams for the façade glass, however, the inner chord had a large unbraced length due to the omission of regular knee-bracing. Similarly, the bottom chord had a large effective length for the uplift load case, due to knee bracing not being able to pierce the bulkheads of the skylights butting up snug to the truss either side. This resulted in a relatively large PFC inner chord and large I-section for a bottom chord. The purlins (bracing for the top chord) of the roof had to step, due to the skylight glass line and sheeting line being on different levels. Additionally, the purlins form part of the skylight substructure. The load path was fairly two dimensional and an RHS section was used. For the Atrium glass transoms, large SHS were used due to the wind, and gravity load cases being very similar correlating the sections’ similar radii of gyration in each direction, it was also aesthetically preferred.

Media screen:  The screen consisted of a large SHS outer frame, as the facade and surrounding over cladding required a 200mm flat fixing face, it was also beneficial at the one end, as a part of the screen had to remain cantilevered to span across the crane void, which would only be filled later with structure. Considering hollow sections’ optimal spread of material away from the center of gravity it gave good results when relating stiffness/size ratios.

Were there any challenges in the fabrication of the project from the Engineer’s design – if yes, please tell? Tell more about fabrication and erection process if it was complex, difficult, innovative etc.

The manufacturing was straightforward, the main difficulty was during erection, the site has virtually no laydown areas with very limited access. The internal cladding support was all done by hand, accurate setting out of beveled columns gave a suitable platform to fix the substructure at awkward angles and positions as per the Architect’s design. The main Atrium roof is very high, and tower cranes were relied on for erection, difficulties were accessed and space as well as supporting lattice columns until the trusses were fixed in place.

What is special/ unusual/ innovative/ aesthetic about the steelwork/cladding in this project?

The final steelwork visual was not part of the architectural intent, therefore hiding it as effectively as possible while forming part of multiple systems and serving its purpose. To accommodate this architecture, it resulted in large unbraced lengths and a peculiar arrangement of members. There was also a large emphasis on keeping the tonnage down to accommodate the Green Star rating.

How did the project team work together (e.g Contractor involved early, challenges/ease of communication etc.)?

Design stage:   The Engineer and Architect liaised and correlated intent and final design with BIM level two, this was vital to ensure clash detection as the complex facade shapes where hard to interpret on two-dimensional drawings.

Shop drawing stage:  Even though detailed sheets were prepared, it was almost completely unused at this stage. Since such a large emphasis was placed on BIM, the model was an accurate reflection of the drawings. This allowed the Structural Steel Detailers to use the engineering model and import it straight into Tekla Structures software. Member lengths, connections, and positions translated from the model kept turnaround times for shop drawings and queries to a minimum. It also resulted in industry standard repercussions, where certain information pertaining to the length of the member can be omitted from engineering drawings and can technically only be used for design intent and setting out purposes.

Erection stage:  The Engineer worked directly with the Sub-Contractor to ensure the complexity of the information was carried over to the final item. BIM was also used on site, as the model was issued directly to the Sub-Contractor, allowing them to interrogate the model on site.

Tons of structural steel used 115 Tons
Structural profiles used All readily available profiles

Project Team

Project Team Role Company
Nominator KRU Detailing CC
Client/ Developer Redefine
Architect Paragon Group
Structural Steel Detailer KRU Detailing CC
Structural Engineer Sutherland
Engineer Sutherland
Quantity Surveyor MLC
Project Manager WBHO
Main Contractor WBHO
Steelwork Contractor Central Welding Works
Steel Erector Central Welding Works
Cladding Manufacturer Façade Solutions
Cladding Supplier Façade Solutions
Cladding Contractor Façade Solutions

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Rissik Street Post Office

What is the purpose of the structure/ project?

The structural steel is intended to act as a supporting frame of the existing building as it was previously damaged by fire in 2009.

What was the brief to the architect?

To restore the post office landmark to its former glory.

Was the project envisaged in steel from the start? If not – why was it built in steel in the end?

Yes as this was the most effective way of achieving the desired support within the existing structure.

Give a brief description of the structural framing. What type of sections were used (e.g. hollow, cellular, I beams etc) and why?

305*305*97 UC was used for the supporting columns that tied into the existing brickwork. Channels and angles made up the girders that support the floors in the upper levels of the building.

Were there any challenges in the fabrication of the project from the engineer’s design – if yes, please tell? Tell more about fabrication and erection process if it was complex, difficult, innovative etc.

The greatest challenge on this project was the allowed space to conduct the works in a safe and secure manner. As this was a restoration project great care had to be taken in the erection of the structural steel as these were to create support for the entire structure. Each of the structural members had to be measured on site to allow for precision fabrication further to the installation each section had to be monitored due to the damage caused by the fire in 2009 – special care had to be taken with the installation of the steel members and the connections to ensure sufficient and strong support. 

What is special/ unusual/ innovative/ aesthetic about the steelwork/cladding

in this project?

The post office was constructed in 1897 and has survived several disasters over the years, implementing the structural steel as a support structure within the existing building allows for the building to be structurally sound and prevents previous damage from compromising the integrity further. 

How did the project team work together (e.g contractor involved early, challenges/ ease of communication etc.)

All parties from start to finish worked in an orderly and disciplined manner allowing each trade to follow the other. Also allowing for multiple trades to conduct works simultaneously within a confined space.

Tons of structural steel used 130 TONS
Structural profiles used UB, UC, ANGLES

Project Team

Project Team Role Company
Engineer Not provided by nominator
Quantity Surveyor Not provided by nominator
Project Manager Not provided by nominator
Main Contractor INKANYELI
Cladding Manufacturer Not provided by nominator
Cladding Supplier Not provided by nominator
Cladding Contractor Not provided by nominator
Corrosion Protection
Not provided by nominator
Corrosion Protection
Paintwork Contractor
Not provided by nominator
Photographer, Photo competition MPW STEEL CONSTRUCTION
Photographer, Other submitted images Not provided by nominator

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

RCL Foods Head Office, Westville

This project was undertaken in the framework of an extraordinary collaboration of the developer/landlord/contractor, tenant, architect, interior designer, branding alchemist and technical team. Somewhat of a ‘rescue operation’, we engaged by the developer to redesign a new corporate head office for RCL Foods after construction had commenced on the site in Westway Office Park. With a semi basement parking structure well underway for a generic commercial office block designed by another architect, the tenant decided that a bespoke design solution was imperative and the project entirely changed course. Key to advancing the conceptual approach for the workplace was an appreciation that the building was to be a pivotal part of creating a new culture for an amalgamated business of five individual corporate acquisitions. Driven by a desire to create Africa’s best and largest food company in the future, the directors of RCL Foods commenced weaving a non-corporate culture around the principles that people are the business and that the workplace environment should attract and retain the best human resource talent available. Working with the branding alchemist and the tenant engagement of our interior design company from the inception of the design proved to be an excellent decision as the stage was set for a fully integrated concept origination.


The new offices required to accommodate 700 people with an emphatic directive to create a bespoke environment exuding the culture of the business at every possible level. With growth and space planning flexibility demands being central to the physical programme, the need for a multiplicity of different meeting and collaborative spaces and a focus on food were imperatives. A desire for spatially connected workspaces with emphasis on providing a focal and legible public interface was expressed together with the need to create a variety of functionally usable external spaces.


The concept of the building delivers a significant linear atrium connecting all spaces and operations of the office building. This space is entirely given over to circulation, spatial connectivity and acts as the heart of the building. The application of steel, envisaged from inception, is expressly utilized in many primary and secondary components in the atrium space and is intended to be on show as the ‘theatrical’ material.



The functional and visual focus of the atrium is the cascading staircase which extends from the entrance area to the uppermost floor and connects all levels. This is created from a single 450mm diameter tubular section which almost impossibly spans up to 13m between bridges which connect the floors on either side of the atrium. This stair displays cantilevered treads and is carefully crafted to connect to the bridges comprising universal beams and other sections to produce visually light elements in the space.


Steel is deployed variously through the building internally to produce an architecturally dynamic environment. Its sometimes subtle presence, is almost unperceived and this amplifies its extraordinary role in this building as both a ‘star actor’ and ‘cameo parts’!  The extensive balustrading is a composite of delicate perforated steel plate and both steel and stainless steel sections. This delivers a lightness and transparency which is rarely evidenced in such components. The exposed lifts in yellow lift shafts exhibit the workings of a standard lift and this displays the importance of steel components in a lift. The flush glazed atrium enclosure is neatly supported in slender universal beam sections set unconventionally to accommodate blinds.


In an office which is unusual in nearly every way, all internal space divisions are unconventional.  Curvilinear glazed meeting pods, which precariously cantilever into the atrium, rely on curved steel tubular sections to support internal roofs and glazing, delivering a light and delicate support system. All internal meeting spaces and cellular office are created of freestanding steel framed structures where light tubular sections are deployed to support walls, glass and ceilings in many cases. Steelwork is seldom hidden and consistently treated in a dark charcoal colour, it demands both visual appreciation and indeed in its main roles, a ‘take your breath away’ awareness.


While RCL Foods is a fundamentally conventional wet-trades construction externally, many solutions to create the architectural outcome demand the use of steel. Hidden steel posts embedded in glazed enclosure, substructures for the signature perforated aluminium solar screens and giant tubular supports for impossible concrete cantilevers offer subtle and functional solutions through the building. Sporadic application of Corten is evident to selected and focal elements externally in the curved planters, gates and deck seating screens. This delivers a warm and crafted quality contrasting the cool grey and white exterior fabric.


This was a fast track project where the office building component was designed on a parking podium already under construction. So while the primary structure was being erected, decisions around methodologies to facilitate a near impossible completion date had to be made. Within the framework of a relatively conventional construction solution, the atrium usefully served as the concourse of construction. To allow efficient construction to proceed, the atrium roof demanded a soft roof using steel beams and lightweight sheeting as opposed to reinforced concrete. This decision, eliminating a forest of scaffolding then allowed the challenge of erecting a 70m long stair and series of connecting bridges to become manageable. Consistent and intense collaboration between Engineer, Architect, Interior Designer and Steel Fabricator became the hallmark of the design and construction process. Early involvement of the Contractor, Fabricator and Structural Engineer with significantly detail concept design at initial stages ultimately delivered a timeous and a remarkable outcome.

Tons of structural steel used      255 +

Structural profiles used Tubular and U.B.

Project Team

Project Team Role Company
Nominator EPA
Client/ Developer JT Ross
Architect EPA
Structural Engineer BPH Engineers
Engineer Not provided by nominator
Quantity Surveyor MLC Quantity Surveyors
Project Manager Not provided by nominator
Main Contractor JT Ross
Steelwork Contractor Rebcon Engineering
Steel Erector Rebcon Engineering
Cladding Manufacturer HB Interiors


Cladding Supplier HB Interiors
Cladding Contractor HB Interiors
Corrosion Protection
Not provided by nominator
Corrosion Protection
Paintwork Contractor
Not provided by nominator
Photographer, Photo competition Not provided by nominator
Photographer, Other submitted images Not provided by nominator

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Radisson Hotel at Silo 6

The Radisson Red hotel located in Silo 6 has art, music and fashion at its core. It is an upmarket hotel that caters to business travellers, international travellers and families. This 252-room Hotel, recently completed, is the first in South Africa of a new offering by the Radisson Group. The vibrant 4-star brand, Radisson Red, caters for a younger, trendier segment of the tourist market.

Situated immediately adjacent to the precinct’s Centrepiece, MOCAA (museum of Contemporary African Art), this project occupies a critical position. With MOCAA as the focus, and the existing BOE building on the opposite side, Silo 6 was designed to complement this composition of three buildings.

Conceptually, the building is a ‘wall’ building that defines the outer edge of the precinct and in mirroring the scale of the BOE building, showcases MOCAA as the focal point. Architecturally, the wall concept is expressed literally through the creative use of rendered brick construction on the East and West facades while the North and South facades reflect the Dockland’s industrial heritage using Steel and Glass.

The punctured fenestration on the East and West facades reflects the rational floor layout of rooms and is expressed using a custom designed protruding Aluminium frame. Juxtaposed against the rough brickwork, this device is a key contemporary insertion in the architectural expression of the building. The building has been awarded a 5-star Green Building status.

The project site had an existing super basement that was designed to accommodate a generic building on top of it. During the time when the basement was constructed, the client (V&A Waterfront) wasn’t 100% sure whether the building would be a hotel. The Rezidor Hotel Group/ Raddison Red later become the operator of the Radisson Red Hotel at Silo 6.

The Radisson Group has their own design requirements for creating a hotel and the brief to the architects was to adhere to their standards and to create a hotel that would maximise the number of rooms as well as fit into the Silo District, which has become a landmark in South Africa’s Mother City.

To create a commercially viable hotel, stay within the brand standards and requirements, and maximise keys of the third Radisson Red hotel in the world, the design team had to think out of the box. Not only did they have to respond to an existing structural grid that didn’t relate to a hotel configuration, but they also had to carefully consider how the north façade of the hotel would complement the Silo 6 district.

The structural gymnastics that the team employed included introducing V-columns to create a layout that would accommodate a hotel, and the north façade of the hotel included interesting steel solutions and careful placement of cladding pannels to create a playful ‘random’ rhythm within the framework.

There is a concrete frame structure with steel elements clipped onto the façade. The north façade is articulated with balustrading and channels that are fixed to the concrete structure with steel. The façade articulation speaks to the notion of an industrial area, which is appropriate for the context of the Silo 6 precinct which includes a working shipyard, a museum and other landmark buildings.

 The design team fixed vertical flat plates to the concrete frame structure in a series of angles to frame the balustrade modules. The beta fence panels (fencing panels) were then fixed to tubular sections. The concrete slab was then finished a C-channel that is fixed to the concrete edges, which created a unique and beautiful façade articulation. Red cladded panels create privacy for guests on their balcony. Bright red was an aesthetically pleasing way to introduce colour into the north façade while speaking to the operator’s brand, and created a seemingly random pattern on the façade.

One of the challenges that the design team encountered was a manufacturing error that led to an incorrectly sized balustrade height. The calculation error led to the design team having to adjust the design to avoid remanufacturing of the balustrade modular panels.

 The architects inherited a restrictive structural grid which informed a very constrained north suite façade configuration and the design team was tasked with articulating the north façade to create a playful ‘random’ rhythm in the framework. The balcony spaces vary in size due to the staggering of the red panels, which creates a beautiful façade.

 The challenge of the manufacture height was successfully overcome by the design team and the contractor working hand in hand to deliver the project on time and within budget. The team were able to collaborate to look at ways to achieve the desired results by modifying the fixing detail.

Cladding profile/ type used Klip-Tite & IBR
Cladding area/ coverage 270m2
Cladding tonnage 1,4 tons

Project Team

Project Team Role Company
Nominator Global Roofing Solutions
Client/ Developer Not provided by nominator
Architect Peerutin + Design Space Africa
Structural Engineer Arup South Africa
Engineer Not provided by nominator
Quantity Surveyor MLC Cape Town
Project Manager Not provided by nominator
Main Contractor Not provided by nominator
Steelwork Contractor Not provided by nominator
Steel Erector Not provided by nominator
Cladding Manufacturer Global Roofing Solutions
Cladding Supplier Global Roofing Solutions
Cladding Contractor Chartwell Roofing
Corrosion Protection
Not provided by nominator
Corrosion Protection
Paintwork Contractor
Not provided by nominator
Photographer, Photo competition Not provided by nominator
Photographer, Other submitted images Not provided by nominator

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

House Matthews

In 2014 Colin Matthews, owner of Mercury Steel construction, had a vision to build his dream home in Helderfontein Estate, Fourways on the Jukskei river banks. The majority of the home was designed to reflect his passion for steel, both structurally and aesthetically.

Mercury Steel was a reputable company doing most of its steel work for Century Property Developments for the last 20 years, with a turnover of R25m a year in the residential market. They’ve won awards in galvanised steel construction and been a pillar in the design and execution of many Century buildings within their developments.

Sadly, Colin passed away in January 2017 leaving the house with only the structural steel skeleton complete. Richard Wands and Jessica Hofmeyr, who owned the neighbouring stand, purchased the stand with completed structure from the deceased estate and selected Century Property Developments to complete the house in honour of Colin Matthews.

The brief to the architect was to ensure that steel remains the dominant element in the design, creating strong features yet also a light quality due to the slabs and walls sitting within the webs of the I beams. Externally, the use of steel is dominant and aggressive, with massive beams and columns. In the interior, steel is forever present, but subtle and discreet where the beams form part of the floor finish, the soffit and the walls. Steel enables a lean design and removes the obstructiveness of large brick / concrete columns and beams, which would otherwise be required for all the large openings. The steel allows natural light to enter the house and exposes the home’s magnificent view.

Structurally, the house consists of 3 floors and the structural frame was designed and built mainly with 254×146 x 37kg horizontal I Beams to carry the middle and upper level exposed concrete suspended slabs. The larger beams enable the suspended slabs to sit perfectly in the web of the steel beams. 152 x 152 x 37kg vertical H Columns allow the brickwork to be flush and the windows to sit neatly within.

The roof structure’s top frame is constructed with 203 x 133 x 25kg I beams with the rafters being steel IPE 160 sections. Purlins consisted of 150 x 65 x 20 x 2.5 CFLC sections tying the structure together.

Cantilevered balconies are supported by 160x80x3 RHS columns running down the front of the house on an angle, creating a top-heavy cantilevered look, with the house seemingly on stilts.

The gables and the garages were cladded with Safintra Trimflute Sheeting. The requirement for the cladding to sit flush with the 254 I Beam steel outer flange meant we had to use a 140mm cement brick to allow for spacing, and the battens needed 20mm square tubing.

From the driveway to the bottom floor, the site has a 7m fall, making access extremely difficult. Steel sections had to be placed by a crane sitting on the top level. The steel frame ensured that the building was plumb and square, which then made setting out walls and leveling slabs etc. easy to achieve. Ensuring that services all ran in the concrete slab and into the walls – without seeing any of the conduits – was a challenge and holes had to be drilled through all the internal horizontal beams to allow for water, gas and electrical piping. These areas had to be strengthened with structural fins within the steel web. Outer walls had to be built with the outer brick laid flat and the inner brick on edge, to ensure that the plaster didn’t protrude beyond the steel internally. This resulted in a clean finish, with the edges of the I beam flanges being flush with the plaster.

Regular meetings were required early on to mitigate challenging details which could not be foreseen in the planning stage. The Contractor, Engineer, and Architect were constantly involved to ensure that the building could function structurally and aesthetically without compromising the look of the steel or any other part of the house.

A challenging project indeed, but very rewarding and evident in the final product.

Thank you for considering the possibilities that steel in a domestic setting offers, both structurally and with very pleasing aesthetics.

Tons of structural steel used 21.396 Tonne
Structural profiles used I – 254x146x37 / I – 203x133x25 / H – 152x152x37 / Ipe 160 / Cflc 150x65x20x2.5 / Rhs 160x80x3


Cladding profile/ type used Safintra Trimflute – Colour Thunderstorm
Cladding area/ coverage and tonnage 208m2 / 1.04 TONNE

Project Team

Project Team Role Company
Nominator Century Property Development
Client/ Developer N/A
Architect Studious Architects
Structural Engineer C-Plan Structural Engineers (Pty) Ltd
Engineer C-Plan Structural Engineers (Pty) Ltd
Quantity Surveyor Century Property Development
Project Manager Century Property Development
Main Contractor Century Property Development
Steelwork Contractor Wrought Iron Factory
Steel Erector Wrought Iron Factory
Cladding Manufacturer Safintra (Pty) Ltd
Cladding Supplier Safintra (Pty) Ltd
Cladding Contractor Nico Grobler Dakoprigting
Photographer, Photo competition Nextgen Group (Pty) Ltd
Photographer, Other submitted images Nextgen Group (Pty) Ltd

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Nike – Pulse

The Brief

A ‘linear sculpture’ fabricated in Grd 316 stainless steel and consisting of approximately 200 vertical members all supporting triangular, faceted panels which may interconnect in some instances.The entire sculpture to be assembled in Johannesburg and then dis-assembled and packed for shipping to Oregon USA.


Being able to interpret one mans abstract vision into a physical entity is a skill few people would possess.So, begun an intense series of planning meetings, idea swopping, mock up builds and lot of trial and error.Once again technology played an important key role as ideas became drawings and concepts began to take physical shapes. A strong partnership between the design team and the fabricator very quickly saw practicalities being introduced to the various mock ups and the individual shapes started to become recognizable as multi-dimensional sculpture began to form.

The Build

Several weeks of extremely detailed planning coupled with many hours of highly intricate detail drawing saw over 400 completed parts arriving at the fabrication shop. Each part an individual shape or cut and all carefully numbered were subjected to an intense polishing process before being set out in carefully prioritized sequences ready for assembly.

Each assembled component was certified by a member of the design team as he checked every angle, position and assembly order, before once again being processed through the polishing systems. The base, in total over 20mts long, was constructed in 8 individual sections consisting of 2 lasers cut 5mm plates separated by 150mm spacers, and fitted with tubular sleeves at specific angles, which would support the vertical members. The base sections were bolted together to from a waving ‘snake like’ platform which would be positioned into a water feature at the site.

The 180 vertical members are Ø38 tubular sections each with uniquely laser cut slots to accept the faceted plates. Each of the 300-laser cut 3mm plates were uniquely shaped and precision bent at various positions and welded into slots on the vertical posts.The vertical members are then slot guided into the sleeves in the base unit and the faceted plates form a multi- dimensional figure of a runner, which morphs into another figure as one moves along the length of the structure.


The components, after a final touch up polish, were wrapped in bubble wrap and carefully tied down into timber crates, with great care being taken to avoid the possibility of chaffing on a long sea journey.

Intricate packaging lists were compiled indicating every position of each component in the crate, which would assist when unpacking in Oregon. Crates were sealed at the fabrication shop before travelling by road to Durban, by sea to New York and then by train to Oregon before a final road trip to the site, Nike’s new World Head Office. Spiral Engineering’s commitment to quality and professionalism have once again been recognized and we are honored to have been appointed as a partner on this prestigious International project.

Tons of structural steel used 5 Tons
Structural profiles used All Grade 316 Stainless Steel Structure, Base Plates 6 thk, CHS Posts at angles, and 3mm bent shaped plates at precise angles and positions. All components CNC Laser Cut and bent to fit in exact position and angles.
SA content Design, supply, fabrication, polishing and Packaging 
Cost of steelwork Fabrication and packaging R 2 million.

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Discovery Head Office

The Project entails the development of the new Head Office for Discovery Health in the Sandton Precinct and consists of three towers with glass façades and large skylight roofs on the two larger towers and required extensive steelwork support for the facades at roof level and between the three towers.


There were two key factors within Discovery’s brief.

First was to create an architectural statement that captured the essence of the Discovery brand, and that it could be identified with going forward.  They wanted a building that embodied their core values.

The second factor, that follows on from the first was to improve efficiencies in the day to day working of the company. 

The Discovery building was conceived from the inside out. This concept resolved itself into two large, sun filled internal atria around which the open floor plates were arranged.  The atria are enclosed by 2800sqm of glazed roof, with all pause areas and agile spaces opening into them.  Connecting these atria to one another is a central concourse, within which a stack of escalators links double volume bridges that stitch the floorplates together.  The concourse space was conceived as a “grand central station”, a literal and figurative interchange between the company and its clients.
The roof of the building is a landscaped retreat, accessible to all employees, where the philosophy of holistic approach to health, an integral part of the company’s core values, is physically expressed.

A key feature of the building is the floating “nose” of the west tower which projects over the Katherine/ Rivonia intersection.  To make a statement that fitted with the scale of the building, we needed to cantilever 17.5m over 6 floors.  This posed a significant structural challenge that was eventually solved with the introduction of 3 massive concrete beams that project over the length of the cantilever.  The floors are then suspended from these beams on steel, concrete filled, columns.

Another challenge was the large atrium roofs.  We wanted these to provide as much light as possible which meant the engineering of a bespoke support solution that was visually unobstructed, but structurally stable.  The solution from the façade engineers is an elegant tension truss lattice that supports both the weight of the glazing as well as resisting the up forces created by the movement of air over the top of the glazed panels.


There are a number of separate steelwork structures on the Project many of which are worthy of exposure and as such a brief description of the major elements is covered below.

SkyLight Roofs:

The Skylight Roofs are probably the most iconic and interesting structures within the development and encompass an extremely innovative design concept allowing them to convey a minimal structural expression of openness.

The major construction challenge presented by the design was the requirement to effectively pre-stress the Main and Secondary (‘so called ‘Glass) Trusses post installation to ensure their bottom chords remain in tension under all loading conditions. The pre-stress is achieved by the incorporation of ‘ so called ‘ light pull-down bars which were then post tensioned on the main support trusses after installation using purpose made tensioning brackets and permanently installed strain gauges to ensure correct tensioning was applied. The ‘ Glass ‘ trusses were post tensioned using a much simpler ‘ nut turning ‘ method on their pull-down bars.

The bottom chords on the Main Support Trusses plus pull-down bars are all imported high tensile KINEX Bars from China with aesthetically pleasing end connection clevises and couplers. The Glass Trusses utilise normal structural steel round bars throughout.

The Fabrication of the steelwork had its own challenges particularly with respect to the Main Support Trusses which are of tubular construction with high tensile KINEX Bar bottom chord members. The main challenge here was in the design of the truss intersections which involved many hours with the design Engineers and careful component fabrication and fit-up in the workshop to achieve the required result.

Cantilevered Floating ‘Nose’:

The Cantilever floating ‘nose’ is a stunning architectural feature and an engineering marvel which enables the large cantilevered six storeys to be supported by the massive post-tensioned concrete beams at roof level.

This steelwork needed to be accurately manufactured with beams rolled to seven different radii seamlessly butt welded together to form the perimeter of the floors which supports the façade which follows the ever changing curvature of the building. The six floors were assembled and supported on five temporary columns at ground level, each floor has five 508mm diameter CHS columns which are concrete filled and hang from three massive post-tensioned concrete beams at roof level. After all the floors had been erected and the top of the CHS columns cast into the concrete beams, the temporary columns at ground level were slowly and methodically cut out while the structure was closely monitored for settlement deflection. This steelwork was on the critical path with a very tight programme. The final result talks for itself.

Façade Support Structure at Roof Level:

The façade support structure requires a 200x200x4.5 SHS to follow the three dimensional curvature of the top edge of the buildings, as this member could not be successfully rolled to the required radii with the required finish we opted for a purpose made curved SHS using plates which were laser cut to the required radius and shop welded to form the 200x200x4.5mm curved SHS which is curved in plan and segmented in elevation. The entire structure was erected to tight tolerances required by the façade glazing contractor and finished to the high standard required by the architect.


When asked to write a report upon the above-mentioned project, immediate feeling of pride and achievement come to mind. This undoubtedly is one of Spiral Engineering’s finest sets of stair ever produced. The project team management and general site feel was on another level of professionalism and hence the success of the project.

We were set out the task of creating 11 features Spiral stairs which created an illusion of stairs which are ‘falling’ through concrete voids combining glass and plate balustrades. Together with this, we had 4 additional sweep stairs (2 in either atrium) to complete the access to the lower floors. Other works completed were the Executive Pergola and Smokers Canopy at Roof level, all boasting subtle curves in plan and elevation to the highest quality standards. Added to this was the design supply of the reception Green wall spanning over 6 floors creating a magnificent welcome to the Discovery staff and guests.

Feature Spiral stairs. (88 tons)

Each one of these stairs were double box stingers 600mm deep which alternated between glass and plate balustrades. The stairs spanned from floor to floor with no intermediate support thus the requirement for full penetration site welding to cast in channel systems to handle the eccentric loads. The handling of these stairs posed challenges in the accuracy and the very strict structural welds were required. Due to program restraints the stairs were hoisted using block and tackle off specially designed structural scaffold systems and were positioned to within very tight tolerance requirements. Full penetration site welding was carried out with every weld preparation and weld inspected and tested by Sotiralis Consulting Engineers.  It was a complete team effort from the Contractor, Sub Contractor, Engineer, Quantity Surveyor, Architect and Project Manager to achieve the desired effect. The real challenge was to perfect the flawless smooth white look that the Architects were looking to achieve. Special attention was placed on weld preparation as well as high quality welding and dressing thereof. The final product having the sense of multiple floating steel stairs throughout the Atriums. This really created the WOW FACTOR which you experience when entering these amazing spaces. The stairs were finished off with 16mm laminate full frameless glass and stainless steel grab rail. The sweep stairs on the lower level also consisted of the same high quality finish. Special attention to the tapering entrances and exits did add to detail during fabrication but the smooth clean look was definitely achieved. The full package was completed on time and a great experience for all parties involved.

Jakob green wall (1 Ton Stwk, 2400m Jakob Rope, 3750 No Jakob components)

This unmistakable green wall greets you at the entrance of Discovery Sandton.  The green wall spans over 6 floors and primarily comprised of grade 316 stainless steel 10mm cables, fittings, climbing ladders all fixed to slimline bracketry spreading the loads and minimizing any further stresses to the already loaded slab edges. The Green wall follows the curve of the slab edges and spans in length sections suitable to accommodate a dynamic green wall loads throughout the Growth formations. There are curved supporting channels which are staggered between floors which are perfectly set out creating a continuous slim look. This one of a kind green wall did come with its own challenges. Testing of the plant growth as well as a full pre made mock up off site were carried out to ensure the forces, loads and greenery were all covered to ensure the best possible quality for the client. There was no second chance as this installation was scheduled to be installed as a finishing trade, hence the fit first time and mockup requirements were critical to the success of the installation.

Pergola and Canopy (22.5 Tons)

Similar to the Stair structures these were high class fabrication with subtle curves in plan and elevation assembled and installed on the roof without overhead crane access.  The attention to detail by the Architect on these structures was exemplary and was cause for much consternation for our finishing teams. There was no shortcut and every curve and detail were thought of by the professional team and placed as much of a challenge as the Atrium stairs in that these were not just secondary structures and we were expected to maintain all the quality and fabrication standards as we had done for the stairs.

Completion date of full project ± NOVEMBER 2017
Tons of structural steel used TASS – 700 TONS





Project Team

Project Team Role Company
Nominator TASS Engineering
Client/ Developer Growthpoint / Zenprop JV
Architect Boogertman & Partners
Structural Engineer, Skylight Pure Consulting
Structural Engineer, Main Building Sotiralis Consulting Engineers
Quantity Surveyor RLB Pentad Q.S.
Project Manager Morta Project Managers
Main Contractor Tiber / WBHO JV
Steelwork Contractor TASS Engineering
2nd Steelwork Contractor Spiral Engineering
3rd Steelwork Contractor Nancy Engineering
Steelwork Erector Onpar Steelwork Erection
Corrosion Protection
Paintwork Contractor
DRAM Industrial Painters
Photographer, Photo competition Megapix Digital

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

Club 2

The new Club 2 Building in Hazelwood, Pretoria, is set to become a landmark property in the city. The modern, industrial yet retro look and feel, combined with the striking curved roof, has made it a hotspot for local tenants.

In 2015, Atterbury Properties appointed Hofman Architects to design a space that would accommodate a gym as well as office spaces. Situated on the corner of Pinaster Avenue and 18th Street in Pretoria, Club 2 builds on the prestigious Club One office building that was designed and completed in 2011. The five office floors of Club One are leased to the University of South Africa, with popular retail areas such as Hogshead Craft Beer and Hudsons The Burger Joint occupying the ground floor section.

The brief from the client to the architect evolved over time.  Initially, the brief was to design a building for Planet Fitness on the intersection South of the precinct, with an office component to make up the bulk on the Northern end of the property.  When the design was presented, Atterbury was so impressed that they decided to move their head office to the new building. 

This decision changed the brief to the architect in a few ways. The office component had to mirror the design of the client’s offices and it had to move to the prominent South corner of the building. The gym, in turn, had to move to the Northern section of the property without it losing visibility and exposure from passers-by.

The ideal design for a gym of this magnitude is a “warehouse” type structure.  With this in mind, the design was always envisaged as a steel structure. The office component has a beautiful, industrial theme, which can easily be accommodated by steel structures.

The building is constructed of a curved portal frame structure with large I-beam sections. 

The roof cladding that was specified for the project is KlipTite by Global Roofing Solutions. The cladding was cranked around the curves of the portal frames with custom made flashing detail to accommodate the curved roof.  The walls were constructed out of a combination of brickwork and the Imison lightweight wall system.

One challenge that the design team encountered was cladding the curved radius of the large section I-beams.  To overcome this challenge, these sections were manufactured and not rolled. Ensuring that the exact placing of these sections aligned with the columns on site was challenging, as were the flashings that were needed. The design team had a few flashing prototypes made and in the end a custom designed flashing had to be created to accommodate the curved roof.

The curved portals on the property are particularly unique, innovative and aesthetic. The portals step up and down over box gutters to let natural light into the interior spaces, and they step in and out over the façade to create deep overhangs to accommodate shaded public spaces over the entrances of the building.  This design element is what gives the building its unique appearance. 

When working on a steel structure, attention to detail is of paramount importance as any design flaws and errors can be quite unforgiving. The contractors, engineers and architects worked well together to resolve any details as and when they arose. Ongoing inspections of the steel work and a culture of collaboration and innovation led to the successful outcome of Club 2.

Cladding profile/ type used Klip-Tite
Cladding area/ coverage 3400m2
Cladding tonnage 18 Tons

Project Team

Project Team  Role             Company
Nominator Global Roofing
Client/ Developer Atterbury
Architect Hoffman Architects
Structural Engineer DG Consulting
Quantity Surveyor
GK Project and Cost Engineering
Main Contractor Wilson Bayly Holmes Construction
Steelwork Contractor LTS Steelwork
Steel Erector LTS Steelwork
Cladding Manufacturer Global Roofing Solutions
Cladding Supplier Global Roofing Solutions
Cladding Contractor Cladco

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.

33 Baker Street

What is the purpose of the structure/project?

 To upgrade a very old building, to accommodate multiple tenants of which the main tenant is Standard Bank.

What was the brief to the Architect? 

To convert the existing building into a contemporary design with a status commensurate with the expectations of Sasol Pension Fund and Standard Bank as a tenant.

Was the project envisaged in steel from the start? If not, why was it built in steel in the end?

The curtain wall application to an existing concrete structure demanded a steel frame to achieve a modulated façade.

Give a brief description of the structural framing. What type of sections were used (e.g. hollow, cellular, I beam etc) and why?

 Mostly I-Beams with angular trusses was used to hold the roof.

Give a brief description of the cladding process (complexity, difficulty, innovation etc).

In view of the fluctuating conditions inherent to the existing concrete structure, it was required that steel substructures be designed which would have sufficient adaptability to address the different conditions whilst being able to achieve a modulated curtain wall design.

Were there any challenges in the fabrication of the project from the Engineer’s design – If yes, please tell? Tell more about fabrication and erection process if it was complex, difficult, innovative etc.

Baker Street at its core was an upgrade of a current concrete building that was to be equipped with new structural steel to accommodate impressive looking glass and facades with paneling on the exterior. Essentially the overall appearance of the building was to be modified. The problem was getting accurate and existing concrete dimensions from site to work with the new Engineering/Architectural changes.

The Engineering drawings which was received had rugged ideas of what was required, in terms of the structural steel and, for a job like this, accurate measurements were of utmost importance.

In the end consultation and coordination between the Architects, Engineers, Glass-and Curved Façade team members, and Sheeting members had to work inwards from the outer most edges of the sheeting and glasswork.

However, the information provided by SVA, with regards to where everything had to be, completed, and getting the required support structures in design form, from the Engineers, allowed the Structural Steel Detailers to reconstruct what was needed from the ground up. The required structural steel did fit in, although tightly in places, but worked. Coordination on this level made everybody sure that everything would accurately fit in the end, especially using the exact three-dimensional (3D) Tekla models as well as proper DWG drawings, where everyone was able to double-check everything on their end. What followed from the new type of coordination with the Structural Steel Detailers leading the way was:  Problems being sorted out quickly in meetings, with nothing left unanswered where after it was checked and updated after meetings between all parties.

What is special/ unusual/ innovative/ aesthetic about the steelwork/cladding in this project?

The steel frame principle allowed sufficient flexibility to achieve a curtain wall cladding accentuated with aluminum solid elements as well as utilizing the steelwork at roof level to support a balcony structure. The essential idea was to achieve a simplicity of structures that could be erected within a limited time.

How did the project team work together (e.g. Contractor involved early, challenges/ease of communication etc.)?

The design demanded a meticulous coordination of the Engineer’ requirements, the curtain wall shop drawings and the detailing of the solid aluminum elements during the pre-contract documentation stage and on-site construction. The coordination of the various disciplines, as well as management of the process on-site, proved to be efficient.

Tons of structural steel used 210 Tons
Structural profiles used Hot Rolled I-sections, Angles & CFLC

Project Team

Project Team Role Company
Nominator KRU Detailing CC on behalf of Central Welding Works
Client/ Developer Redefine- Sasol Pension Fund
Architect SVA Architects
Structural Steel Detailer KRU Detailing CC
Engineer Sutherland
Quantity Surveyor Matla
Project Manager TPM project management
Main Contractor WBHO
Steelwork Contractor Central Welding Works
Steel Erector Central Welding Works
Cladding Manufacturer Hunter Douglas (Fancy Facades)
Cladding Supplier Hunter Douglas
Cladding Contractor Hunter Douglas
Glass Facades Diri Glass (Glass Facades)
Rigging/Cleaning Rails Gravity Access
Photographer, Other submitted images Central Welding Works

If you were a part of this project, and your company details are incorrect or missing – please notify the SAISC so that the error can be corrected.