PART 1: CONCRETE IN THE DESIGN OF A UNIQUE LUXURY HOME IN GEORGE, SOUTH AFRICA

By Eamonn Ryan

In an exclusive interview, Justin Bien of OneRoom Design Architects shared insights with Concrete Trends into the design and construction of a unique luxury home in George, South Africa. The discussion revolved around the substantial use of concrete in the foundation and structure of this extraordinary family residence. This is Part 1 of a two-part series.

“The project began with a family purchasing a property in Wilderness, a scenic area near George. They envisioned a luxury home constructed entirely from concrete, from the foundations to the walls and roof. Tragically, the husband passed away at the beginning of the year construction commenced, halting the project and leading the family to consider selling the property. Despite this, the superstructure of the house is complete, showcasing a remarkable feat of concrete engineering,” says Bien.

He explained that the homeowner insisted on using concrete exclusively for the entire structure. This included the foundations, walls and roof, with a waterproof additive integrated into the concrete to ensure durability. The concrete work was undertaken by a specialised company called Triple P, which provided the necessary materials and expertise for such a demanding project.

The initial plan for the home involved a two-story structure with a ground floor and first floor. During excavation, the team opted for a raft foundation instead of conventional strip foundations. A raft foundation, Bien explained, is essentially a flat slab that sits on the ground, providing a stable base in sandy conditions like those at the beach site. This method helps to evenly distribute the weight of the building and prevents issues related to shifting sands.

The decision to use a raft foundation was made by consulting engineers, who play a crucial role in determining the structural integrity of a building. Bien highlighted the importance of collaboration between architects and engineers, noting that while architects focus on design and concept, engineers ensure that the structure can withstand the environmental conditions. In this project, the consulting engineers were instrumental in adapting the foundation to the sandy soil of the beach location.

The architect’s journey

Bien mentioned that he was not the original architect for the project. The initial design and concept were created by Eddie de Silva, an architect based in George. However, Bien’s firm was brought in to create a 3D model and eventually took over detailing and construction. This transition is not uncommon in large projects, where different professionals may handle various phases from design to completion.

“The house was designed to be a completely smart home, with all systems centrally controlled. This level of automation included adjusting blinds, regulating light levels and programming temperature controls to optimise comfort throughout the day. Bien described the extensive use of conduit for cabling to accommodate the smart home system, emphasising the importance of hardwiring everything to ensure reliability and avoid the issues associated with wireless systems, such as battery dependency.

“While wireless receivers were considered, the decision to hardwire all systems was driven by the need for reliability and redundancy. The client wanted to avoid scenarios where a loss of internet connectivity could render essential home functions inoperable. Consequently, the home was equipped with an Ethernet backup to ensure continuous operation of all systems. This approach required an extraordinary amount of conduit and cabling, making the home a marvel of modern electrical engineering,” says Bien.

The project required meticulous coordination between architects and engineers. While the architect typically issues construction drawings detailing the layout, window heights and other design elements, the engineer provided the construction drawings for the all-concrete structure. This included specifying the extensive use of rebar and ensuring that the concrete construction met all structural requirements.

The excavation process for the home was particularly challenging due to the sandy soil conditions. “Initially, the engineer recommended a raft slab foundation, positioned 1.5m below ground level to ensure stability. However, as excavation progressed, the team encountered issues with sand collapsing into the site. To address this, they had to create a 3m basement, which involved additional excavation and careful management of the sand to prevent further collapse.”