The South African National Roads Agency Ltd (SANRAL) head office is not only modern in design but reflects the organisation’s commitment to “enhancing eco-efficiency and identifying and managing or eliminating environmental risks”.

According to project architect Edward Brooks from Activate Architecture, the demand for maximum energy efficiency meant they needed to try and keep the sun off the facades in summer while still allowing controlled penetration of the winter sun in the morning and afternoon and maximum daylight without excessive glare throughout the year.

This resulted in a building with a striking, elegant shape. “The facades with double glazing and mesh screens and the thermal mass roof are the key design elements, reducing the heat load and energy demand,” says Brooks, who designed the building together with colleagues Michael Magner and Rob Serman.

The completed building has generous views out from all work stations as well as lots of natural light and the general feedback so far has been very positive. Brooks says early readings show that the building is “much more efficient than the typical office building.”

Since commercial buildings are responsible for ±15% of all energy used in the world today[1], and since heating, ventilation and air conditioning (HVAC) account for ±40% of commercial building energy use, considerable attention was given to these systems – we are perhaps seeing the “rise of the mechanical engineer” in terms of a substantial contribution to sustainability in the built environment.

Mechanical engineer Peet Pelser from Plantech said their task was accomplished with a combination of good thermal insulation and solar screening. The stainless steel mesh used on the facades is visually attractive while possessing the kind of screening properties required from an architectural as well as mechanical engineering point of view. The specific product was imported from Germany, but Pelser believes there is a good market for local firms to produce similar products with known u-values and the high dimensional tolerance and quality needed for architectural mesh.

A wide range of other elements contribute to the building’s sustainability: a comprehensive environmental management plan, a fully integrated building management system, a roof garden, low energy lighting, solar water heating, deep overhangs for sun control and support for recycling initiatives.

Careful consideration of materials included local sourcing of building materials, Forest Stewardship Council certified timber, low volatile organic compound paint and carpets, and the use of recycled steel content and aggregate. It also meant reduced use of cement, polyvinyl chloride (PVC) and products containing formaldehydes, and the elimination of ozone depletion potential (ODP) refrigerants and insulation materials.

Project manager Ed Rouillard summarises some of the challenges:  “In essence, a new untested team of top firms and professionals, all leaders in their field but not experienced as a team, had to work together.  There were hectic timing issues and we had to produce something that was not only an energy-efficient building but one that could measure up the Green Star requirements of the Green Building Council.”

See the full feature in the October – November 2011 issue on p36. Images: Christoph Hoffman (www.chp.za.com)


[1] According to the World Resources Institute World Resources Institute: www.wri.org