SUSTAINABLE BUILDING
He explains:“ The original red-pigmented concrete is echoed in new pavilions, paired with elements like pre-cast stairs, polished terrazzo floors, in-situ roofs, and textured plaster. The material speaks to context, to craft, and to tactility. Existing and new spaces were opened to surrounding views through large frameless glass panels, maximising natural light and complemented by skylights. Underutilised areas were transformed by demolishing walls and extending spaces into the landscape. This is truly a palimpsest of architecture: respectful of its past, yet transformed into a 21st-century home for contemporary living.”
According to the client, Isaac Chalumbira:“ Having lived on the same street for over 20 years, House Millar has always been special to me. It’ s a Brutalist modernist landmark. When it went on the market, I was the first to view it and saw its potential to preserve Johannesburg’ s architectural heritage while reimagining it as a contemporary retreat in Sandton. I commissioned Daniel van der Merwe of Leaf Architects, known for his expertise in architectural concrete and indigenous landscaping. The brief was to respect the architectural integrity of Stan Field ' s award-winning structure, while enhancing it for a 21st-century lifestyle. " He adds,“ The result would be a home rooted in its past, responsive to the present, and created for future living needs.”
Architect’ s notes
Guided by the principles of Wabi-Sabi that embrace imperfection and simplicity, the design aimed to embody barefoot luxury living.
The material selections and spatial transitions were to evoke natural warmth and biophilic authenticity. The brief also included making the Rock House off-grid with solar power, a borehole, rainwater for the garden and eco-pool, and hightech features to facilitate circadian rhythm lighting and wireless connectivity.
Overall, an ethno-botanic approach informs the integration of landscape and its‘ primordial place’.
The intervention is underpinned by a biophilic and site-syntonic design methodology. Existing features such as rocks, topography and trees served as biomimicry-based design generators. A mature tree was incorporated into living areas. An atrium becomes an indigenous‘ forest’, and living roofs blur the landscape with its surroundings.
Water operates as both a spatial and phenomenological medium. At the main entrance, a waterfall over an existing rock defines a liminal threshold, and with its adjacent reflective pond, it calibrates acoustics and surface reflections. An indigenous lily pond interfaces with the main bedroom, and merges biofiltration with visual continuity of indoor / outdoor spaces.
Finally, off-grid sustainability is advanced via integrated solar infrastructure and a borehole-fed, UV-purified water system.
Large existing rocks were respected where they were, and we worked around them to allow the rocks to be integrated as part of the biophilic design approach.
What is Brutalist design?
A Brutalist building is a stark, massive structure from the mid-20th century, characterised by raw, unfinished concrete( Fr: béton brut) and exposed structural elements. It emphasises bold geometric forms, a monolithic appearance, and utilitarian function over ornamentation – often appearing blocky and imposing, with rough textures and repetitive modular shapes.
Brutalist architecture is an architectural style that emerged in the United Kingdom during the 1950s, within post-war reconstruction projects( Wikipedia). They are characterised by minimalist construction, showcasing the bare building materials and structural elements over decorative design.
www. tobuild. co. za | autumn 2026 49