Firstly alternate systems of cooling the buildings were explored. These were designed around the potential offered by the hot, dry, semi-arid Highveld climate.
An evaporative air cooling system was designed, which effectively passed fresh air across a saturated surface, thereby humidifying the air and causing its temperature to drop by between 5 and 6 degrees. The cooled air is then pumped into the building and is evacuated through windows openings, thereby ensuring a constant supply of fresh cool air to the interior. The system is cost effective, resourceful and healthy. It is based upon the systems of air cooling which form part of the architectural legacy of desert countries like Iran.
A manually operated system of louvers was designed for the sun protection to the east and west elevations of both buildings. The louvers comprise a lightweight steel frame onto which is slid a sheath of 50 per cent opaque shade cloth. This material both allows views out when the louvers are shut and also allows ventilation across the louvers.
In this way a lightweight system of individually controlled louvers is made. The typical problem of high heat gain associated with the heavier louvers in use elsewhere in South Africa is overcome in a cheap and elegant manner.
Both buildings were designed around the need to ensure that all office spaces would benefit from direct light rather rely on expensive artificial lighting. This led to long thin buildings which were 11 and half meters wide. This permitted a central walkway with office depths kept to a maximum of 6 meters.
The corridor on the top floors of both buildings is split open to allow the penetration of natural light deep into the buildings.
The architectural language is free from sentimentality and is direct and straightforward, in line with the architect’s desire to design buildings which would be both elegant and purposeful.
The significant energy savings achieved made both buildings successful investments for their clients.