The Boogertman + Partners building is a 2 storey structure, vs the 3 storey structures of the other 4 adjacent buildings. We wanted to maintain the same overall height per building for aesthetics and for as much volume as allowed, within an imposed height restriction. These restrictions guided us in the choice for a vaulted steel upper roof structure. The Apex is at exactly the maximum height allowed, to create a multi-volume production office space.
The brief called for a division of spaces over 2 levels, for public (Meet /Make) and private (Work/Staff) space. Usable height was to be maximized, in effect creating space over 2 floors, usually used for 3 floors. A Higher floor to soffit height was also achieved. The upper ‘drawing office’ was to be enclosed in a light and airy enclosure, with maximum void space, and light penetration from a vast northern exposure.
Was the project envisaged in steel from the start? If not – why was it built in steel in the end?
The previously developed buildings, and other 2 buildings of the second phase where all concrete framed & roofed buildings. The one other building also reverted to a steel roof for programme reasons. The Boogertman + Partners building was planned and designed as a steel-roofed building, for quick construction, it’s ‘industrial warehouse’ aesthetic, and as a cost vs time consideration.
Give a brief description of the structural framing. What type of sections were used (e.g. hollow, cellular, I beams etc) and why?
The large Steel portal frames, where designed as 456×190 H-sections, with cross bracing in 150 square hollow section tubes. The back of the portal frames rests on a concrete beam and the front ends extend down to ground floor level.
The space between portal frames is filled in with a framed glass curtain wall on both the north and south sides. The ridge is off-center, creating a mansard type aesthetic, similar to a warehouse type saw-tooth roof arrangement. On the south side, smoke ventilators are incorporated within the portal frame structure, in a vertical application. All AC & Electrical lighting services are exposed in the open double volume space. The bare steel was painted in corporate CI colours of Black and White with the B+P Orange as a highlight color. The external shading structure also needed to be integrated with the portal framing in a seamless fashion, using tubular steel sections.
Give a brief description of the cladding process (complexity, difficulty, innovation etc)
The lightweight roof structure has quite a complex sandwich structure, to accommodate the external sheeting layer, intermediate insulation layers for sound, heat, air gap, and acoustic lower ceiling layer, all of which free-spans across the totally exposed steel portal frame. Long discussions with the acoustic consultant, Ivan Linn ensued to find the right balance between a lightweight, affordable roof, and the required sound attenuation & occupancy comfort levels.
Because all services were exposed, the fixing, suspension, and overall finish of lights and AC ducts had to be carefully planned. There was no ceiling void in which to hide any services.
GIve a brief description of the Light Steel Frame Building element of the project. (Notable features/ achievements made possible by LSFB)
The contractor’s programme was tight, and so also space on site for materials and maneuvering. A Spider crane was employed to lift and place pre-fabricated steel portal frame sections into place. Finishing of the steel and connections were carefully planned because all steel is exposed and visible, and welding had to be very neat.
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 Structural Engineer, from Sutherland Engineers, worked closely with Iguana, the main contractor and Central Welding, the steel fabricators to comply with a very tight programme, shop drawing approval process and limited site access for erection of the steel framing. (more info from Sutherland/Iguana/Central welding)
What is special/ unusual/ innovative/ aesthetic about the steelwork/cladding in this project?
The steel portal framing and bracing is totally exposed and very much part of the overall aesthetic. Bright bold colour is used to dress & celebrate the steel structure. The steel portal frame is a strong & integral design element, framing the building, and identifying the double volume office space.
How did the project team work together (e.g. contractor involved early, challenges/ ease of communication etc.)
All parties, from the Architect, to the Engineers, the contractor and the fabricator worked hand in hand to overcome challenges. A lot of back & forth was needed to get everything just right. Any successful project has to rely on mutual respect, and individual contributions as well as a concerted team effort, all of which was prevalent in this project.
|Completion date of steelwork||April 2018|
|Completion date of full project||June 2018|
|Tons of structural steel used||28.5 tons|
|Structural profiles used||I Beams, SHS’s and CFLS’s|
|SA content – if this is an export project||Yes done in SA|
|LSFB / LIGHT STEEL FRAME BUILDING WORK|
|Completion date of LSFB work||April 2018|
|Completion date of full project||June 2018|
|Tons of LSF used||4.38|
|Span of trusses and Kg/m2 (if applicable)||None applicable|
|Profiles used||Canopies and Screens
|Type of cladding||KLIP-LOK 406’ PROFILE 0,58MM|
|Completion date of cladding||May 2018|
|Cladding profile/ type used||KLIP-LOK 406’ PROFILE 0,58MM|
|Cladding area/ coverage and tonnage||720m2|
|Nominator||Boogertman and Partners (Pty) Ltd|
|Client/ Developer||RPP Developments|
|Structural Engineer||Sutherland Engineers|
|Quantity Surveyor||Pentad Quantity Surveyors|
|Project Manager||CPD Project Management|
|Main Contractor||Iguana Projects|
|Steelwork Contractor||Central Welding Works|
|Steel Erector||Central Welding Works|
|Cladding Contractor||Steel Roofing|