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.