The three-storey 78 Corlett Drive 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. A restrained lighting treatment was called for to draw attention to the façade once the sun goes down.
https://www.crown.co.za/case-studies/10197-unique-facade-lighting-distinguishes-one-of-sa-s-greenest-buildings#sigProId496bf7163b
A new contemporary office development, designed by Daffonchio & Associates Architects along Corlett Drive in Johannesburg, 78 Corlett Drive, aims to set a new standard of vibrant and trendy co-working office spaces in a cutting edge six-star Green Star certified building.
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 houses 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.
It is at night, however, that the building comes into its own. “We were asked to design the façade lighting for the face of the building that ties into the slatted feature façade,” says Byron Lottering from Regent Lighting Solutions (RLS). “After being supplied the artist’s impression and details of what the intended facade would look like, we designed and custom manufactured the lighting required to fit seamlessly into an extrusion of the facade. The Linear Mini was used in sizes of 800 mm, 1600 mm and 2 400 mm at 4 000 K.
Jose Loureiro, design manager at RLS, notes that the project did come with challenges. “The objective was to provide feature lighting to distinguish the façade and not to light anything up. We had to play with the intensity of the light and had to tone it down twice to get it subdued enough for passers-by to be able to see the lines but not flood out the front area with light,” he explains. “A lighting design was done for the façade to calculate the output onto the road and, being a local manufacturer, we were able to provide samples for the architect and client so they could be taken on site at night and tweaked.”
Another challenge was ensuring that the linears looked neat in louvres. “Essentially we were given a 50 mm wide aluminium ‘box’ and needed to incorporate a recessed linear light on the end. We had to work together with the façade engineer to marry the elements. In the end, the solution is a snug, neat fit, with the addition of a lip to ensure that the louvres are flush,” he says. The manufacturing process was well coordinated to ensure that the lighting system doesn’t detract from the look of the louvres and no broken lines are visible. The colour of the powder coating was even coordinated to ensure an exact match.
“This was a good example of the suppliers being involved early enough in the process to work together with the various architectural and engineering teams to supply samples on site. Everyone is very happy with the overall effect,” notes Loreira. From a maintenance perspective, it is easy to check the drivers behind the panels in the case of any failures, and the diffuser is easily peeled out to work on the LEDs. The fittings have built-in IP protection and are powered through cables which are fed through the 800 mm ‘fins’. “It was a bit of a challenge powering the fittings,” he explains, “But with some dialogue with electrician on site, in the end it wasn’t a major issue.”
Loureiro’s advice to architects is to consult with the lighting suppliers as early as possible; “Even when in the concept or budget stages,” he says. “That gives us more time to come up with better solutions for the project. As an example, wiring isn’t often initially considered, which necessitates chasing after the effect, yet our involvement from an early stage of the project can quicken the process.”
Elsewhere, the landscape and exterior parking area of 78 Corlett Drive is illuminated by the RLS Piazza Post top 48 W and the basement parking area was fitted with Linear Mini fittings to keep in line with the modernistic straight line design style on the facade of the building. The Linear Mini was supplied in multiple variations – both recessed and surface mounted – in continuous and in sections from 3 m up to 14 m.
A ‘net zero’ building
As one of the first projects in Africa to be certified Net Zero, 78 Corlett Drive in Johannesburg is leading the local green building sector into a new phase of evolution. The project was awarded a Net Zero Carbon (Pilot) Level 1 Certification in late November 2017, and a 6-star Green Star Office V1.1 Design certification in January 2018.
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.
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.
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.
