House Oldfield Midlands

The Oldfield family were looking for a weekend getaway in the mountains but not too far from home. A five hectare site was found in Caversham Road, Lidgetton.

Architect’s brief

As the family business was involved in the design and erection of steel structures, the architect was requested utilise as much steel as possible.


Description of the structural framing

All columns and external rafters were fabricated in 200×100 hollow sections to allow them to be used for water evacuation. Rafters were simple 200×100 IPE sections. All steel was hot dip galvanised and painted internally where exposed. Externally all steel was left galvanised

Steel cladding

The architect specified steel side cladding to match the roof with only the gables being constructed in face brick.

Challenges

The most challenging part of the project was the detail in the flashings at the interface of the various elements, windows, doors, brickwork, gutters etc.

Aesthetics

The use of steel allowed for high uninterrupted open spaces in the entertainment area as well as clear external areas.

STRUCTURAL STEELWORK
Completion date of steelwork February 2018
Completion date of full project June 2018
Tons of structural steel used 20
Structural profiles used Beams, rectangular tube and cold rolled purlins
CLADDING
Completion date of cladding March 2019
Cladding profile/ type used Brownbuilt profile Chromodek
Cladding area/ coverage and tonnage 1000 sq.m
PROJECT TEAM COMPANY
Nominator Cousins Steel International (CSI)
Client/ Developer The Stonehouse Trust
Architect Joy Brazler Architects
Structural Engineer CSI
Engineer CSI
Project Manager CSI
Steelwork Contractor CSI
Steel Erector Kalleb Rigging
Cladding Manufacturer Arcelor Mittal
Cladding Supplier Global Roofing
Cladding Contractor Kalleb Rigging
Corrosion Protection
Galvanising
Phoenix Galvanising

Eldo Ridge Estate Residence

The steel structure allowed an opportunity to open the residence up with large glazed areas and contrast the heavy mass of the curved brickwork and sculptural concrete elements. The structure achieves a lightness, transparency and legible simplicity with single pitched roofs, straight lines and clean exposed steel structure maximizing natural light and views. Its deliberate contrast creates a composition of spaces of a different character, complementary to the Client’s lifestyle, which required a balance between privacy and modern outdoor living.

What was the brief to the architect?

The brief was to design a unique & modern residence that could take advantage of the extensive views that existed on the site, without compromising the need for enclosed private spaces where the family could live & work. The strong focus on family living called for the brief to address the inclusion of multiple communal areas, balanced by private areas for the individual. Space, natural light & comfort needed to be included in all aspects of the design.

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

The roof structure and the support structure as a steel assembly was a major component of the initial concept, fulfilling the brief for light, openness, views, and modernity. The large rafter spans & spacing that is possible with using steel rafters made it possible to install high-level windows in the bedrooms, satisfying the requirement for natural light and privacy. Steel columns supporting a steel roof structure allowed the living areas to be almost completely glazed and substantially openable, blending inside with outside on opportune days with unencumbered views.

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

Hollow rectangular sections for exposed roof purlins. Lipped channel sections for concealed roof purlins. I-Sections and H-Sections for support columns, beams, and rafters.

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

The challenge on this project was to integrate the strong linear lines and rectilinear forms of the steel structure with the curved organic forms of the brick structures. All of the steelwork was fabricated off-site and then erected on site, which ensured a high degree of accuracy & finish.

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

All steelwork was exposed and visible, resulting in the need for all the connections, fixings and joints to be carefully and deliberately detailed. The roof sheeting similarly complemented the main off-shutter concrete roof in form and needed to be installed in a manner that focussed on the neatness of edges and aesthetic appeal.

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

The Main Contractor was involved very early in the design process, providing valuable insight into the structure and design. The successful collaboration of the Contractor and Consultants from project inception established a harmonious working relationship on site where all were committed and focused on creating a unique & beautiful home.

STRUCTURAL STEELWORK
Completion date of steelwork July 2016
Completion date of full project September 2017
Tons of structural steel used 10 tons
Structural profiles used I-Sections, Lipped Channels
SA content – if this is an export project n/a
CLADDING
Completion date of cladding November 2016
Cladding profile/ type used Macsteel Arona Roofing Novotexi Roof Sheeting
Cladding area/ coverage and tonnage 550m2
PROJECT TEAM ROLE COMPANY
Nominator SNAPP Architects (Pty) Ltd
Architectural Team SNAPP Architects (Pty) Ltd
Structural Engineer Dippenaar & Lapage (Pty) Ltd
Main Contractor NGA Construction (Pty) Ltd
Steelwork Contractor N2 Steelworks
Steel Erector N2 Steelworks
Cladding Manufacturer Safintra – Saflok 700
Cladding Supplier L.R.S. Building Contractors & Suppliers
Cladding Contractor L.R.S. Building Contractors & Suppliers

House Shepherd

The idyllic setting of Monaghan Farm was the main catalyst for this project.  Initially, the house was to be used for weekend getaways, a place to relax and a place for the client’s son to walk around in nature without the barriers of walls and security guards.  Halfway through the project, it became clear that this was a place where the client wanted to live full-time and decided to make this his primary residence.

Brief by the Client to the Architect: The architect brief evolved due to the change of purpose of the property.  Initially, it was to build a modest glass box on the river but then it matured to a full family home.  From an architectural perspective, the client did not want a contemporary modern home, similar to what you see popping up in Sandton and new estates. The desire was to build something that was mid-century modern that had a 60’s feel.  This was difficult for the architect to initially conceptualize, leading the client to reject his initial proposal outright and then sketching a simple structure with a glass box on top and a lower level of two underground wings which he expertly executed.

STRUCTURAL STEELWORK
Completion date of steelwork June 2018
Completion date of full project December 2018
Tons of structural steel used 35.6 Tons
Structural profiles used 254x146x31 UB; 120x120x6 SHS; 

254x254x73 UC; 100775x20x2.5 CFLC

PROJECT TEAM COMPANY
Nominator C-Plan Structural Engineers
Client/ Developer Colin Sheperd
Structural Engineer C-Plan Structural Engineers
Main Contractor Rob Building Construction
Steelwork Contractor Estee Automation
Steel Erector Estee Automation

Naspers Skybridge

The Naspers Skybridge is a pedestrian link between the CTICC 2 building and the Naspers building. The client tasked the architect with designing a new bridge between the new CTICC 2 building and the NASPERS building. This would aid in daily access for Media24 staff, as they did not have enough parking of their own and could then utilize some of the parking bays in the CTICC buildings. This new bridge had to link CTICC 2’s Second Floor with NASPER’s Fourth floor, roughly 13.5m above the road level.

The architects developed various concepts for the design of the bridge. Inspiration was taken from the shape of a tree, interpreted in different architectural expressions. Through workshops with the client (both CTICC and NASPERS) and the professional team, multiply small-scale physical models were built to convey the different design ideas, including an option of steel laser cut panels that form a sculptural support and leaf-pattern balustrade, and another version with steel support “branches”. Ultimately, the design was refined to form a simple yet “raw” aesthetic, with the architectural and structural logic informing the details. A composite wood decking floor in a staggered pattern was used to enhance the “raw” aesthetic, with Rheinzink roof sheeting chosen for aesthetic and practical reasons due to the slanted and curved roof. Panoramic views of the city can be experienced through the full-height glass façades.

Due to the location of the entrances to the buildings, the bridge curves for about half of its length. This creates an interesting architectural experience as one crosses the bridge, while making it possible to see the bridge’s exterior from the inside. Structurally the challenge was to support the curved section only on two columns, with the end part at the CTICC not being able to be supported by the existing building (thus creating a large cantilever that had to have minimal movement at the façade entry point).

The bridge was always envisaged as being constructed out of steelwork – to allow maximum views to the sides and to enable construction with minimal disruption to the street below. The bridge structure comprised mainly Universal Beam and Column sections, with some angles added to support the flooring and a CHS safety rail for window cleaning.

Challenges arose due to the weight of sections, which made moving these sections a challenge during both fabrication and erection. The bridge sections were assembled into just two pieces adjacent to the road, allowing these two large pieces to be erected using a 440t crane during a road closure on a Sunday. The two parts had never been spliced together before erection, with all dimensions being theoretical. The first real fit was therefore on site, and everything fitted perfectly.

Another challenge was erecting the bridge on a windy and rainy day, forcing the contractor to wait for a lull before lifting.

Since the bridge was modelled in 3D, an IFC export was provided to the contractor to aid them in the shop drawing process. In turn, they provided their fabrication model in 3D for approval by the engineer and architect, which ensured that the aesthetic intentions of the professional team could be met.

STRUCTURAL STEELWORK
Completion date of steelwork October 2018
Completion date of full project March 2019
Tons of structural steel used  
Structural profiles used UB, UC and CHS sections
CLADDING
Completion date of cladding No cladding
Cladding profile/ type used Rheinzink
Cladding area/ coverage and tonnage 165m2
PROJECT TEAM COMPANY
Nominator Anchor Steel Projects
Client/ Developer Cape Town International Convention Centre
Architect Osmond Lange Architects + Planners
Structural Engineer Sutherland
Quantity Surveyor Turner & Townsend
Project Manager Lukhozi Engineers
Main Contractor Superway Construction
Steelwork Contractor Anchor Steel Projects
Steel Erector Anchor Steel Projects
Cladding Supplier Two Oceans Metal
Cladding Contractor Naturally Slate

The 1054

The 1054, strategically named after the property’s erf number, firmly places itself on Main Road Walmer, as a pavilion to the street edge.  Main Road has been established, as part of Nelson Mandela Bay Municipality’s Spatial Development Framework Plan, as a new business precinct within the bay and is expanding rapidly. Although business is growing along this main feeder route, many houses have merely been facelifted with a false façade that has really watered down the potential for the strip.

There were two main drivers behind the design of the building

Firstly, The 1054 needed to spark conversation about what is being developed, or not being for that matter along Main Road, and whether you love it or hate it, its intention is to initiate the discussion around what and how the potential of the road should be maximised by creating intrigue where buildings become destinations along the road, which sadly the currently renovated houses do not.  The 1054, is the first building of its kind along the 2.8km stretch of road.  Already within the 12months of the building’s completion, both property owners and developers have started to consider more exciting additions, alterations and in some cases new builds that are adding value to the street.

Secondly, as always, the budget was extremely tight and a design that both made the impact as above, as well as could be cost-effective was key.  The design needed to be stripped back of all the frills that we come to see on many commercial buildings and design a structure that used the

buildings basic structural form to create interest. Through stripping back the building to its essential elements, time could also be saved, which for any developer is advantageous. 

A single dynamic contrasting form to the street was proposed, the construction of which was like that of a warehouse.  A concrete framed base structure, on which precast concrete floor slabs were laid and a supporting structural steel framed upper structure.  Steel sections consisted mainly of square hollow tube and H columns with lattice trusses.  The interior envelope and wall construction used lighter framed steel stud work. The building could be erected rapidly with many elements being manufactured off-site.  Total construction time was 9months with the building coming in below R10, 000.00/m² including all ancillary works.

The building design played with solid and void, not the buildings external envelope, but the contrast of the seemingly solid exterior vs. its light and airy interior, the volume of which connects all businesses within and welcomes people up within the space.  A welcoming surprise to all. 

It was important for the building to be modular so that the ‘structural grid’ could be broken/sub-divided into smaller or larger sections based on the same repetitive GLA to accommodate different sizes of businesses that would establish within the space.  Currently, the building consists of a retail component to the Ground Floor, as it was essential to attract people in as a destination and in turn promote visibility for all other tenants namely the First Floor offices.  To the Ground Floor, we have a new concept restaurant, well-established furniture, and décor retailer and an up and coming hair salon.  The First Floor offices consist of us as an Architectural Practice, Structural/Civil Engineers, Finance House, Freight and a Pilates Studio.  The selection of tenants was fundamental for them to feed off each other but also to ensure the longevity of the mix for the developer.  

STRUCTURAL STEELWORK
Completion date of steelwork January 2018
Completion date of full project April 2018
Tons of structural steel used 1850
Structural profiles used I-Beams/I-Columns/Lattice Trusses/Box Sections/Lip Channels
CLADDING
Completion date of cladding February 2018
Cladding profile/ type used Saflok 410
Cladding area/ coverage and tonnage 1373m2
PROJECT TEAM ROLE COMPANY
Nominator DMV Architecture
Client/ Developer Symbolic Investments Propriety (Pty) Ltd
Architect DMV Architecture
Structural Engineer MEB Consulting Engineers
Main Contractor Jeremy Delport Construction
Steelwork Contractor Bisho Steel
Steel Erector Bisho Steel
Cladding Manufacturer Safintra
Cladding Supplier Clad All
Cladding Contractor Clad All

CTICC Skybridge

The CTICC Skybridge was intended as an above-ground link between CTICC 1 on the West of Heerengracht Street and CTICC 2 on the East. The client asked the Architects to design an enclosed pedestrian skybridge to connect the Cape Town International Convention Centre (CTICC 1) with the CTICC East Expansion (CTICC 2) across the busy Heerengracht Street. Development of the CTICC skybridge was considered critical in enabling the two buildings to function as a single integrated international events hosting venue and providing a seamless visitor’s experience.


The curved skybridge with its slender slanted steel columns has an unusually dynamic aesthetic from outside. The curved route inside provides a dynamic visual experience as one moves across the bridge in anticipation of an obscured end destination. The indirect travelling direction guides the visitor’s gaze outwards and across the historic Heerengracht Street and allows the bridge to become a unique destination in its own right. This purposefully iconic structure pays tribute to CTICC’s core purpose of ‘connecting people’.

The bridge was always envisaged as being constructed out of steelwork – to allow maximum views to the sides and to enable construction with minimal disruption to the street below. Universal Beam and Column sections were chosen to frame the concrete floor and roof, which were both cast in sections in between these steel members, with support provided by Bondek sheeting. Universal Column sections were also chosen for the Vertical members, in order to frame the glass panels.

Circular hollow sections, however, were chosen for the diagonal members to minimise the disruption of the view. The same members were also used for horizontal bracing at the roof and floor level, to keep the section sizes down. Large circular hollow sections were also used for the slanting support columns.

Challenges arose due to the weight of sections, which made moving these sections a challenge during both fabrication and erection. The bridge sections were assembled into

just two pieces adjacent to the road, allowing these two large pieces to be erected using a 440t crane during a road closure on a Sunday. The two parts had never been spliced together before erection, with all dimensions being theoretical. The first real fit was therefore on site, and everything fitted perfectly.

Another challenge was the temporary support of the bridge during erection. This was overcome by introducing the temporary towers, which made the installation much simpler and safer.

Since the bridge was modelled in 3D, an IFC export was provided to the contractor to aid them in the shop drawing process. In turn, they provided their fabrication model in 3D for approval by the engineer and architect, which ensured that the aesthetic intentions of the professional team could be met.

STRUCTURAL STEELWORK
Completion date of steelwork September 2018
Completion date of full project November 2018
Structural profiles used UB, UC and CHS sections
PROJECT TEAM ROLE COMPANY
Nominator Anchor Steel Projects
Client/ Developer Cape Town International Convention Centre
Architect Convention Architects – a JV between Makeka Design Lab cc, SVA International (Pty) Ltd and van der Merwe Miszewski Architects (Pty) Ltd
Structural Engineer Sutherland
Quantity Surveyor Turner & Townsend
Project Manager Lukhozi Engineers
Main Contractor Superway Construction
Steelwork Contractor Anchor Steel Projects
Steel Erector Anchor Steel Projects

 

CCBSA Mezzanine Office

The purpose of the project was to extend the existing storage facilities at Coca-Cola Beverages Africa, CCBSA,  Pretoria west plant. This included a mezzanine office building to be used as a delivery office for the warehouse. The building had to span 21m and be high enough to allow forklifts to pass underneath. In addition, the building was to be constructed in the existing warehouse and whilst the warehouse remained operational.

The brief to the architect

The brief from the client was that forklifts had to be able to drive underneath the office building. This resulted in a truss configuration that spanned 11m and had a clearance of 4.8m

The architectural concept was largely driven by function. The architect had a number of constraints to work with: (i) A building that spans 21m would have to be a truss type structure, and (ii) the truss had to have  transverse elements that works in tension. These members were likely to be large UB sections.

The idea from the get go was to provide an aesthetically pleasing structure with lots of coke red in.

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

A brick structure with a steel truss roof was considered but due to the large spans and limited time available for construction, it was clear that a steel truss would be the most effective solution.  The steel truss was manufactured in the contractor’s workshop and merely assembled on site. This allowed for minimal disruption to the warehouse that remained in use throughout the duration of the project.

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

The 21m spanning truss is made up of I beams. I beams were used due to good stiffness to weight and therefore cost ratio. The fact that I beams are regularly available also added to this choice.

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

Roof cladding was added to protect the gypsum ceiling in the event that the existing roof leaks. The side panels were cladded with soft boards where possible and with glass framed in aluminium where required.

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 structure was assembled under an existing canopy making carnage very difficult. Note that the warehouse remained operational thought the duration of the project. As far as possible, parts were assembled and manufactured off site. Small sections of the warehouse was barricaded off to allow for the construction work. In addition, the contractor had to avoid forklifts that continued to load and off load coke trucks in the warehouse.

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

The inclined I beams in the truss were cleverly cladded with aluminium framed glass.  Clearance for deflection was allowed for to avoid cracking of glass. The clear glass and red board cladding resulted in an aesthetically pleasing structure.

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

The project team consisted of a WSP project manager Tumelo Makubo, Architect Riette Postma from Flaneur Architects and Structural lead Johnnie Strydom from WSP.  WSP and Flaneur Architects works closely with the CCBSA Factory manager, Alan Clark.  Alan provided clear directives of what was required from CCBSA’s side and since WSP, and Flaneur have deliver a number of successful projects in the past, some of which was for CCBSA, the working relationship was professional and vibrant.

STRUCTURAL STEELWORK
Completion date of steelwork 26 September 2018
 Completion date of full project 26 November 2018
Tons of structural steel used 17 tons
Structural profiles used UB Sections
PROJECT TEAM COMPANY
Nominator WSP
Client/ Developer CCBSA
Architect Flaneur Architects
Structural Engineer WSP
Quantity Surveyor JS & Associates Quantity Surveyors CC
Project Manager WSP
Main Contractor WNR Construction Group
Steelwork Contractor RSB Contracts
Steel Erector RSB Contracts
Corrosion Protection
Galvanising
RSB Contracts
Corrosion Protection
Paintwork Contractor
RSB Contracts

No.1 Silo Bridge

The requirement for a pedestrian bridge link between two office buildings was borne out of the need of Allan Gray’s expanding workforce as they out-grow their head office capacity at No.1 Silo building in the V&A Waterfront.

Allan Gray and the V&A Waterfront together with the architect and engineers developed the idea of a linking bridge between the No.1 Silo building and the adjacent Clock Tower building to allow the internal flow of employees between the buildings.

Not far away from the site of the bridge is the defunct Collier Jetty that has a steel gantry structure along its length, historically used to convey coal and later grain. The gantry is constructed from conventional bolted angle trusses – the inspiration behind the truss form of the bridge with matching diagonal angle sections. 

The brief was thus to design and construct a bridge that would allow people movement over the 12,5m span. While it is a relatively short distance the challenge lay in designing a structure that would deal with the movement between the two buildings that are built on separate floor plates by catering for differential lateral and horizontal movements of up to 20mm.

The Allan Gray building has a fully glazed double-skin façade supported off long cantilever fins which are sensitive to additional loads. The bridge, therefore, had to be fixed on one side only, and cantilever without physically touching the glazed façade. As such columns were introduced to support the bridge at the glazed façade allowing unimpeded movement against it. The two columns, 219mm CHS, are braced by 254x146mm universal beams forming a ‘portal frame’ on which the bridge rests and on the other side, it is bolted to the reinforced concrete frame of the Clock Tower building by way of a shear key detail.

To maintain the view corridor between the two buildings, toward the working harbour, the architects motivated for a crossing at second-floor level. Limited space between the buildings, the delicate glazed façade and the limited crane load that could be applied on the podium level between the buildings meant the structure could not be erected in its entirety and craned into position – it needed to an on-site assembly, erected on a scaffold deck.

A rectangular girder comprising 200x100mm RHS sections was designed as the most efficient steel structure to span from the Clock Tower building to the ‘portal frame’ and cantilever a further 1,7m to the Allan Gray floor plate. A spliced connection along the length of the top and bottom chords created parts that could be handled on site. Rigidity is provided by expressed diagonal bracing visible externally as a structural ‘exo-skeleton’, painted red. 

The design team devised connection details between the various parts that expressed the junction of the steel members, in keeping with the industrial, maritime aesthetic. 100x100mm equal angles bolted to gusset plates brace the vertical SHS posts on  the sides of the bridge. 100x100mm SHS brace the underside and the roof level, expressed externally on the soffit and internally below the ceiling finish. Spigot connector splice details were required on the bracing diagonals to cater for the erection sequence.

Where the bridge passes through the double skin façade a flexible EPDM membrane allows for the required movement but also a weather seal. The membrane is protected by overlapping aluminium flashings.

The bridge links offices on two different floor levels – this is achieved by a sloping timber floor within the girder structure. Steel cleats on stub columns welded to beams along the length of the bridge support timber joists at varying heights.

Side wall cladding is Snap Lock profile in Armour Grey colour, selected for its broad pan and narrow flutes with wide rib spacing. Set behind the diagonal bracing, the industrial aspect of vertical sheet cladding further ties the bridge to its maritime setting. Snap Lock is also used for the roof sheeting and in conjunction with a stepped aluminium flashing detail it creates a crisp silhouette of the bridge spanning between the two buildings. 

STRUCTURAL STEELWORK
Completion date of steelwork 05 / 09 / 2018
Completion date of full project 14 / 12 / 2018
Tons of structural steel used 8.1 tons
Structural profiles used RHS, SHS, CFLC, CHS
CLADDING
Completion date of cladding 10 / 10 / 2018
Cladding profile/ type used SnapLock
Cladding area/ coverage and tonnage 48m²
PROJECT TEAM COMPANY
Nominator Loudon Perry Anderson Architects
Client/ Developer V&A Waterfront Holdings (Pty) Ltd
Architect Loudon Perry Anderson Architects
Structural Engineer Sutherland Engineers
Facade Engineer Arup Engineers
Services Engineer Solution Station
HVAC Engineer Arup Engineers
Quantity Surveyor MLC Group
Project Manager Principle Agent  Architect
Main Contractor R+N Master Builders (Pty) Ltd
Steelwork Contractor Prokon Services (Pty) Ltd
Steel Erector Prokon Services (Pty) Ltd
Cladding Manufacturer Bluescope Steel
Cladding Supplier Youngman Roofing
Cladding Contractor Metro Roofing 

 

House 348 Eco

The purpose of the project was to create a single family home within a nature estate with the aim to celebrate steel. The brief to the Architect was to design a double story, single family home to the accommodation requirements of the Estate but to incorporate steel in its many forms as part of the house. The house to be refined and luxurious but have structural steel and steel as a final finishing material.

From inception, the intention of the client was to use steel in the structure as well as a choice finishing product for cladding and privacy screens.

The structural framing was limited to the angled columns and curved roof trusses of the main roof. 245 x 146 I-beam sections forming the angled columns and curved roof rafters were fabricated off site and craned into place.

The choice of cladding was 1,2m x 2,4m x 3mm thick corten flat sheets. The corten with its final rusted finish allowed the steel to fit into the natural environment.

The design opted for hidden fixing and welding of the corten sheets unto the subframe which caused some difficulty. The hidden welding was successfully and innovatively executed. After the exact roof curve was determined the fabrication of the curved trusses did not provide any challenges. The use of steel actually made the process very easy and streamlined.

What makes steel special and innovative in this project is the use of steel as aesthetic and sculptural elements.

From the angled columns supporting the curved main roof to the corten clad box with no visible fixing. This approach created a feel of sophistication.

The Project Team enjoyed this project and all Professionals and Contractors were involved from the concept stage.

STRUCTURAL STEELWORK
Completion date of steelwork July 2015
Completion date of full project April 2018
Tons of structural steel used 10 Tons
 Structural profiles used 254 X 146 I-BEAM; 50 X 75; 50 X 100; 50 X 25 RECTANGULAR HOLLOW SECTIONS
CLADDING
Completion date of cladding July 2016
Cladding profile/ type used 1,2m X 2,4m X 3mm Thick CORTEN FLAT SHEETS
Cladding area/ coverage and tonnage 90m²
PROJECT TEAM ROLE COMPANY
Nominator Recreate Architects
Client/ Developer Structures 2000
Architect Recreate Architects
Structural Engineer Johan van der Wald
Main Contractor Ebcon Builders
Steelwork Contractor Structures 2000
Steel Erector Structures 2000
Cladding Manufacturer Allied Steelrode
Cladding Supplier Structures 2000
Cladding Contractor Mordt Engineering

Project Starzmann

The structure submitted is a new house for a young German couple who reside in Cape Town. Having lived in Germany, where floor space is a premium, they were keen to build a very compact house, which indeed the site also required, being only 542sqm. The site is perched on the upper slopes of Tamboerskloof and was accessed through a very tricky pan-handle. The site itself had a severe gradient.

Our client asked us to design a modern house, that took advantage of the wonderful views of Table Mountain and the City Bowl. Precedent images of cantilevered rooms and timber clad steel framed houses on the west coast of America spoke to their brief.

From the outset we were very keen, to look at a steel framed structure. We wanted to use a system that perched or hovered above the sloping terrain, rather than be embedded into the ground (due to the severe slope on the site). This was largely achieved, with only the garages being constructed using conventional construction methods ie bricks and mortar.

Such was the desire to use this system, we actually drew the scheme twice, so as to have it priced both as a concrete and brick structure, and then a structural steel framed structure, with timber and glass panel infills, to prove to the client, that they would not necessarily pay a massive premium for what we believed would ultimately be the best solution, both in terms of construction type and aesthetic outcome.

The structure is a simple exposed structural steel post & beam type. It utilizes a grid system to modularize infill window, wall & roof components. The post and beam structure is laterally braced by mean of the two polished concrete floor slabs. The roof structure is also constructed using structural steel rafters, fixed to stub columns above a 254x 146mm universal ring beam, thus creating a clerestory all round. The steel framed system allowed us to experiment and play with various cantilevered elements, that add to the ‘hovering’ nature of the building.

 

Generally, the structure uses 254×146 beams to support the exposed concrete floor slabs, and 200×100 IPE columns to support the steel beams. The corner conditions of the envelope were detailed using 150 x150mm equal angles to create a clean negative joint, into which infill window frames and timber cladding can terminate. The upper portion of the 3 storey staircase also uses a 254×146 central stringer to support hidden steel plates that in turn support the cantilevered natural oak treads.

The building’s external walls are infill panels of natural Siberian Larch timber cladding punctuated with aluminium double glazed window and door panels. Generally, both infill types were designed to be full height between floor levels (ie between “I” beams) for simplicity of construction. Special detailing was required in the form of steel flanges to create waterproofing details at the envelops perimeter.

Prior to manufacturing, many design meetings with the steel fabricator, structural engineer, and architect where held, to resolve each structural steel component, how it connected to the adjacent component, and how it connected to non-steel components. Special care was taken to create openings in the universal steel beams (prior to HD galvanizing) to accommodate services in the floor slabs. The construction process was swift due to the simple structural steel frame, which was erected first, with the concrete floor slabs being cast only once the frame was at roof height.

The construction method as described above is not commonly used in the domestic residential environment in Cape Town. Great care had to be taken during construction, as much of the structure was left exposed to create the final aesthetic. To that end, the Project team including the contractor, engineer, and architect, met often in the design development phase to resolve issues that simply do not occur in conventional brick and concrete building methods. Such simple things as linking services through floor/wall junctions where steel I beams exist needed to be thought through and design solutions found.

The project really showed us the great benefits that can be achieved when such a collaborative design process of architect, engineer and builder is undertaken. Working on this structural steel frame building, forced us to consider all aspects and components of the building, prior to manufacture.

STRUCTURAL STEELWORK
Completion date of steelwork June 2017
Completion date of full project 9th March 2018
Tons of structural steel used unknown
Structural profiles used Universal beams and Universal columns
SA content – if this is an export project All made in SA
PROJECT TEAM COMPANY
Nominator   Young Architecture
Client/ Developer  Ingo Bruggemann &

 Katrin Starzmann

Architect Young Architecture
Structural Engineer ADA Consulting Engineers
Main Contractor Team Austin
Steelwork Contractor  Abelia Metal CC
Steel Erector  Abelia Metal CC
Cladding Contractor  Team Austin