Architect Steve Kinsler specified the use of Burnt Apricot face bricks as well as Corobrik concrete pavers and retaining blocks for this project. “Important considerations were that all building materials had to be sourced locally. The closest factory to the site was our Eston Brick factory from which the Burnt Apricot face brick was procured and supplied,” Mike Ingram, Corobrik’s director of sales for KwaZulu-Natal and Border, explained.

Kinsler pointed out that the Green Star rating system awards points for materials sourced from within either a 50km radius of the site or, failing that, a 400km radius. “Burnt Apricot Satin face bricks and NFX and NFP stock bricks were sourced from the Eston Brick factory located 70kms from the site.”

The Sisonke District Office of the Department of Public Works of KwaZulu-Natal is situated on the outskirts of the small town of Ixopo. It is the first of a four phase project and comprises two single-storey buildings – an office block and conjoined maintenance block – as well as a separate garage block. The total floor area measures 858m2, the commercial office area 550m2 and the car park 193m2.

“The office building has a long and narrow form with the north orientation increasing the solar gain in winter and reducing it in summer,” Kinsler said, adding that eco-friendly and sustainable features predominated when it came to both practical features and aesthetics. One of the main stipulations was minimisation of energy usage.

“At the time of purchase, the site was covered with a mismanaged alien tree plantation that had become infested with alien invasive weeds. The new office block has an extensive roof garden that is home to nearly 100 indigenous plant species. The insulation properties of the building were optimised through the roof garden over the main office spaces and the installation of insulation in the cavities of the brick external walls, below the floors and in the roof. All external windows are double glazed,” he added.

Whilst natural daylight minimises the amount of artificial light needed, natural air flow is maximised, removing the need for mechanical air conditioning. Solar water geysers provide hot water while lighting systems use high-efficiency lights fitted with motion sensors.

The offices are naturally ventilated having no ducts for air supply or cooling. A heat-pump circulates warm water through the floors in order to meet winter space heating requirements. Due to the long narrow form of the building, 85% of the interior spaces are naturally lit, whilst motion sensors automatically switch lights off when no-one is in the room.

Potable water consumption is reduced through the use of water-efficient sanitary fixtures and rainwater is harvested for washing cars and flushing toilets. This reduces the run-off from hard surfaces during storms. Cycling facilities are provided for building users and visitors whilst preferential parking is reserved for fuel efficient cars and motorcycles.

The remainder of the site is being returned to its endemic Natal Mistbelt Grassland habitat. All plants are dry land indigenous species with no irrigation requirements.

Ingram pointed out that the use of clay brick further enhanced the holistic environmental value of the project. “Within the environmental sustainability equation, Corobrik offers clay bricks with embodied energy values in line with international best practice for the technologies employed and with thermal performance properties that support superior thermal comfort and lowest operational energy usage. Many generic factors also underpin clay bricks’ environmental integrity, namely durability and longevity, reusability and recyclability, inertness that ensures no release of VOC’s or toxic fumes to impinge on air quality, incombustibility, natural sound insulation qualities, inorganic qualities that do not provide a food source for mould, maintenance free qualities that incur no future carbon debt and earthy colours and textures that sit unobtrusively in natural environments.”

He said that research underpinned this. “Life Cycle Assessment has established that irrespective of house construction type, embodied energy comprises no more than 10 percent of total energy consumed over a 50 year life cycle. Heating and cooling energy comprises up to 40 percent of total energy consumed. Significant empirical and thermal modeling studies into the thermal performance of walling envelopes for houses confirms that thermal mass inherent in clay brick walling as a critical thermal performance property is critical when it comes to achieving thermal comfort and the lowest heating and cooling energy usage necessary for lowering South Africa’s carbon footprint."