Developed by Legaro Properties, the three-storey project is situated on a brownfields site and is well connected to local amenities and existing public transport infrastructure. The design incorporates strong minimalist geometries, with shading louvres acting as a dynamic facade element and passive shading device. The building is elevated above street level, gently interfacing with the ground through a small glass box which will house the main circulation core and a concierge service.

The upper ground floor of the building will house a mixture of vibrant open co-working spaces and cellular offices, interspersed with social and formal meeting spaces, all revolving around a central coffee bar located in the triple-volume daylit atrium. The first floor has additional co-working spaces and larger formal offices to cater for a diverse variety of tenants.

Convenient location

78 Corlett Drive is ideally located within 1 km walking distance of six bus stops (Putco, Metro and Gautrain); and within 450 m walking distance of taxi stops. A number of local amenities are situated within a 400 m distance, including a pharmacy, gym, bank, convenience store, restaurant, school, medical centre and dry-cleaning outlet.

The project is targeting an Innovation point under the Green Star tool for promoting the use of electric cars by providing electric-car charging facilities as part of the base building infrastructure, and dedicated bays for electric vehicles. Six fuel-efficient parking bays dedicated to hybrids and other fuel-efficient vehicles, and five dedicated motorbike parking spaces, have been preferentially located close to the main building entrance. In addition, seven staff and three visitors’ bicycle racks have been provided, together with a cyclist’s changing room, shower and lockers.

Energy conservation

An energy model of the building was generated in the design stages, comparing 78 Corlett to a notional building model. The building design showed an improvement of 100% (net zero operating emissions base building) over a SANS 10400 notional building.

The building’s peak electrical demand is actively reduced through a photovoltaic solar system on the roof that will tie in to the grid. All enclosed spaces are individually switched, making it easy to light only occupied areas; and hot water will be provided efficiently with small, high-performance electric under-counter geysers installed in each bathroom, which alleviate the need for long runs of insulated hot water pipes. Geyser electric requirements will be supplemented by the PV array on the roof.

Separate energy sub-meters are provided for lighting and power to accurately monitor energy consumption. The behaviour of occupants and users of the building is critical to reducing consumption, and the owners are targeting an overall consumption of 75 kWh/m²/year, far less than the 200 kWh/m2/year SANS10400 XA requirement. Carbon emissions have been reduced to 92 kgCO₂/m²/year.

Indoor Environmental Quality

The design allows a direct visual connection to the external environment for 80% of the Office Useable Area, thus optimising natural daylight within. A high level of thermal comfort is ensured by addressing the internal operative temperatures through modelling and ensuring they are within the ASHRAE Standard 55-2004 Acceptability Limits for at least 98% of occupied hours.

100% of the Usable Area is mechanically ventilated and provides ample good quality outside air by demonstrating a 66% improvement over and above the SANS 10400-O:2011 requirements. Cooling is provided to the building via air cooled chillers, which means that the building does not need to use water to cool the building.

Managing Waste

A project specific Waste Management Plan was developed to minimise the contribution of waste going to landfill during construction and operations. A 40% reduction of the quantity of Portland cement was targeted as an average across all concrete mixes, together with a 60% recycled content of all steel by mass on the project and 50% (by cost) of all timber products used in the building and construction works were specified to be Forest Stewardship Council (FSC) Certified Timber, reused or recycled timber.

The building’s design includes a Waste Recycling Storage area of 19 sqm to encourage building users to recycle all waste where possible in order to minimise their waste footprint. Recyclable waste, including paper and Ccardboard, and plastic, glass and cans, will be collected by Whole Earth Recycling every two weeks.

All selected gaseous and fire suppression systems and thermal insulants have an Ozone Depleting Potential (ODP) of zero, to eliminate any contributions to long-term damage to the Earth’s stratospheric ozone layer.

Water Efficiency

Sub-metering of major water systems is in place, and low flow fittings have been specified throughout. The building does not make use of a fire sprinkler system, which helps to reduce potable water wastage. And the Xeriscape landscaping has been designed to minimise the consumption of potable water for landscape irrigation.

By setting ambitious targets for more sustainable construction and operations, the developer has shown consideration not only for environmental concerns, but also for occupant health and wellbeing, and tenants’ bottom lines.