Ries Shaw Architects were commissioned to provide a Distribution Warehouse of 25 000 sqm and an Office Building of 3 000 sqm on a sloping site alongside the N3 Freeway.
The site is triangular. The siting for the Warehouse was chosen for ease of access but is also along the longest boundary. This is the most elevated area of the site. The Architects capitalized on this acropolis setting with a sleek but detailed response which celebrates the effortless linear quality of Steel Buildings.
THE DESIGN BRIEF
- A distribution Warehouse for storage and subsequent distribution of a range of products.
- An Office Headquarters and Admin support building
A single, large, steel sheeted Warehouse was designed by the Architects with steel cladding being the main aesthetic.
The site is relatively remote, so the use of lightweight elements of great strength was the obvious choice. This is exactly what steel provides.
Carefully edged and defined office and ablution elements are strategically cut into the large steel box to contrast and enhance the steel box while defining clarity of purpose. White edging contrasts with the dark colour of the sheeted box which is further enhanced with lighting.
A steel structure was designed by Kantey and Templer structural engineers measuring 14m at the eaves and consisting of reinforced concrete perimeter columns on a 24 x 24 m grid supporting steel lattice trusses. 3x Spine lattice girders rationalized the spans and member sizes. The resultant configuration was easy to fabricate and erect.
A brief description of the structural framing
The main warehouse structural frame comprises interconnected trusses and lattice girders supported on a column grid of 24m by 24m. For economic and practical reasons the lattice girder trusses comprise I sections and angle sections and the trusses comprise angle sections. The canopies comprise triangular tubular trusses for aesthetics where required and I sections and angles sections elsewhere for economical and practical reasons.
In order to develop an efficient structural configuration for the tilt-up concrete walls, an 8m bay spacing was selected. Under normal circumstance this would render the purlins as single span and thus less efficient, arrangements were however made for the supply of 16m long purlins which allowed for much more efficient double-span purlin design.
The use of steel structure allows for wide spans to achieve the required uncluttered interiors essential for large scale economical storage. The steel structure is split along the center with a sloped polycarbonate ridge line step to allow light to enter. The structural engineers were able to maintain continuity of the main perpendicular trusses through the ridge step in order to allow for improved design efficiency of the structural steel. Dark grey coloured steel compliments the red fire water supply pipes and the white underside of the insulation blanket, so the structure is celebrated as the main event.
Loading on the long side of the Warehouse was required. The triangular site shape came into play and resulted in a saw tooth loading dock configuration. The Architect and Engineer combined their efforts to provide a practical solution, marrying structure with the quite intricate loading configuration with carefully placed support steel and a 3 dimensional circular hollow section steel edge beam (or triangular lattice). The downpipes from the canopy gutter were concealed within circular hollow section canopy columns. The canopy columns were integrated into the concrete dock structures which eliminated the need for separate concrete stub columns and foundations. The mono pitched roof supplies a linearity which moderates the bulk of the warehouse with a quintessential steel aesthetic response.
The Architects further modulated the warehouse form with subtle stepped roof and angled gable planes. Extended eaves added practicality and are joined in an angular configuration at the gables. Hot rolled structural steel girts were selected in lieu of the conventional cold rolled girts connected with additional cleats to the concrete corner columns in order to establish stable raking gable wings. The steel aesthetic is thus further celebrated by these contrasting sheeting planes that make great use of sunlight impacting at various times of the day giving the building a liveliness. Exterior up-lighting accentuates the looming eaves, highlighting the steel support structure.
The crisp, clear nature of this simple steel building on the horizon can be appreciated from far off, which was important to the Architects due to the project’s freeway setting. The subtly angled edges change the overall image as one’s angle of vision changes when passing by. The result demonstrates the rewarding potential of the Essential Steel Box.
The warehouse structure is clad with dark grey concealed fix steel sheeting and opaque white translucent sheeting. The translucent white sheets were positioned to coincide the sloped apex ridge step and sloped gable step with a horizontal eaves strip thereby forming a narrow starkly contrasting white frame against the dark grey background.
This simple trio of concrete boxes in the office block contain large vertical steel louvres that dominate the aesthetic of the freeway elevation. The Architects naturally opted for steel as the appropriate material.
These over-scaled steel elements are framed in coloured steel and filled with punched aluminium panels. They perform their sun control function and consciously celebrate the steel material connection with the warehouse. Steel allows for the subtle connection to the concrete frames being only at the top and bottom.
The scale and design of these elements again celebrate the close relationship with the freeway and the changing perspective while passing by.
Impressive technical aspects of the project
The architect used striking angular features within gable end steps, sides and the roof apex step. This means that the gables have cantilever triangular wing walls that project beyond the perpendicular longitudinal side elevation walls which required special consideration from a structural engineering perspective.
In order to keep a consistent theme, the architect wanted to create a low profile edge to define the large 24m deep truck loading canopy. An innovative solution was required since the spacing between the main external support columns is 32m. The structural engineers, Kantey & Templer, proposed a triangular tubular truss as the main external edge support element. This proved to be an effective solution since it provided several desirable outcomes. Firstly, the exposed edge angle was 60 degrees which matched that of the gable step. Secondly, the tubular truss created an aesthetically pleasing exposed structural element. Thirdly, the canopy box gutter downpipes could be concealed within the tubular columns; and finally tubular sections provide the most efficient structural sections for the compressive axial forces created in large-span trusses.
Hot-rolled structural steel girts were selected in lieu of the conventional cold-rolled girts which were connected with additional cleats to the concrete corner columns in order to establish slender but stable and striking inverted raking gable wings.
As is often the case in warehouse projects; construction speed is of the essence. In order to facilitate rapid construction, a decision was made to use 8m wide tilt-up precast concrete walls. This resulted in the adoption of an 8m wide truss bay spacing which also worked well with the concrete surface bed joint spacing. Cold-formed lipped channel purlins make up a large proportion of the total structural steel mass of the building and must, therefore, be designed efficiently. In line with this objective, the preference is to have multiple span purlins. Under normal circumstances, it would not be feasible to utilise 16m purlins due to fabrication and transportation constraints. This specific requirement was stipulated within the tender documentation and the contractors were able to arrange accordingly in advance allowing for an efficient purlin design.
How does this project demonstrate the benefits of steel as a material?
The use of structural steel offers several general benefits for warehouse construction including: extensive off-site fabrication resulting in fast on site erection and installation; large roof spans resulting in high volume spaces with a low density of internal columns; structurally efficient lightweight construction resulting in cost effective structures.
In this particular case the versatility and relatively slender structural strength of steel has facilitated the design of an aesthetically pleasing warehouse building.
What is special/ unusual/ innovative/ aesthetic about the steelwork in this project?
In order to render warehouses financially feasible, the structural steel design needs to be as light as possible. Under normal circumstances, the result is a simplified box with uninspiring aesthetics. Where elaborate architecturally pleasing warehouses have been developed, this has often resulted in a heavier and therefore more expensive design. In this instance, the professional team was able to design a warehouse structure that is both contemporary and aesthetically impressive but also as financially economical as a typical box-type warehouse. A relatively low additional cost has been applied to the external structural features of the warehouse to produce the most impactful visual impression but at a negligible cost considering the scale of the structure.
The result is an impressive warehouse structure immediately adjacent to the National N3 carriageway that provides passers-by with unexpected and visually appealing building outline with striking angular features that are accentuated by the elevated and diagonal orientation of the structure relative to the roadway.
Project motivation editorials are provided by the project nominator. If any technical details, company names or product names are incorrect, please notify the SAISC so that the error can be corrected.
|Physical address of the project
|Harrison Cato Ridge
|Google Maps link|
Completion date of steelwork
Completion date of full project
Tonnage and steel profiles used
605.24 Ton (including Canopies)
Completion date of cladding
Cladding profile/ type used
Roof: Saflok 700 AZ200 0.55 Rain Cloud Cladding: Widedek AZ200 0.55 Thunderstorm
Cladding area coverage
39 200 m2
|Project Team Role||Company|
|Nominator||RIES SHAW ARCHITECTS|
|Client/ Developer||GROWTHPOINT PROPERTIES|
|Architect||RIES SHAW ARCHITECTS|
|Structural Engineer||KANTEY & TEMPLER|
|Civil Engineer||KANTEY & TEMPLER|
|Electrical Engineer||EG AFRICA|
|Fire Engineer||NATIONAL FIRE & SAFETY|
|Quantity Surveyor||KANTEY & TEMPLER|
|Project Manager||GROWTHPOINT PROPERTIES|
|Steelwork Contractor||PARAGON STEEL STRUCTURES|
|Steel Erector||PARAGON STEEL STRUCTURES|
|Cladding Manufacturer||Safintra South Africa|
|Cladding Supplier||Safintra South Africa|
|Cladding Contractor||MJC Industrial Roofing|
|Corrosion Protection||SIGMA COATINGS|
|Paintwork Contractor||INSIMBI COATINGS|
|Photographer, Photo competition||ANDREW GRIFFIN PHOTO|
|Photographer, Other submitted images||ANDREW GRIFFIN PHOTO|
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.