Green architecture aims to design with the elements of the earth not only not being harmed, but also consciously used to minimise carbon footprint. This amazing house in Sandton, Johannesburg is such an incredible example of building using ‘green’ practices – this building has environmental issues at its heart. The consideration of sun protection, solar radiation, energy and water consumption, landscaping and sustainable systems have all been considered and carefully integrated into an architectural aesthetic. The result is a home that is comfortable, efficient, sustainable and most of all unique.
Although designed around the principles of climate responsive design, comfort, and water conservation, this building has used these design methodologies to create an aesthetic that is still guided by the traditional architectural ideas of composition, symmetry, hierarchy and progression. Nevertheless it challenges conventional ideas of domestic architecture and offers a new ‘‘green aesthetic’’.
The primary concept of the design is the mediation between interior and exterior spaces. To this end, a second envelope of planted steel structures creates individual ‘‘green bubbles’’ of tempered microclimates for each living space to open onto. These provide cooler intermediary spaces in summer and sunny protected areas that collect warmth in winter. The results are mediating spaces that naturally pre–condition the air that enters and circulates into the home. The same planted steel framework concept is used for solar shading and results in a living cladding that almost envelops the entire northern façade.
The building is able to change in appearance and environmental response as the seasons transform the surrounding landscape. The resultant aesthetic caused by this design strategy is unusual and ever changing.
The stepped footprint of the building allows the penetration of the morning winter sun into the living spaces, while blocking out the harsh afternoon sun. This stepping of the buildings also allows for the form to be fragmented into a more visually interesting series of smaller volumes. The smaller volumes produce a structural efficiency with small spans across simple load bearing walls. The individual volumes allow varying roof heights above each space and create a visually interesting profile through simple, efficient forms. A triple volume entrance hall defines the spirit of space and abundance of the house. The staircase rises in the volume to a double height glazed window facing north through planted solar shading. On the south side another double height window affords soft natural light to flood the house.
The house has a comprehensive energy strategy, with a sealed and efficient thermal envelope, and carefully arranged passive solar gain. A sophisticated solar energy system provides all heating requirements. An extensive photovoltaic array is installed. Summer cooling is by effective solar shading and supplemented with direct evaporative cooling. These have been integrated into the architectural aesthetic through the stone chimneys that mirror the planted ‘‘green chimneys’’ that temper the external microclimate bubbles.
The house collects all available rain water and recycles its waste water in a garden wetlands system. Only three potable taps are fed with filtered municipal water, all other water is produced by the intensive water conservation and recycling strategies. The garden wetlands and storage dam create another microclimate that encourages biodiversity and a restorative approach to urban dwelling.
Courtesy ERA Architects