The interior of the building was gutted and existing office partitions and ceilings removed and replaced with new drywall. Existing windows, façade panels and frames were replaced with high performance curtain walling and double glazing to provide a high performance façade, enhancing the thermal performance of the building envelope and reducing the energy demand on the HVAC system.
Only the ground and first two floors of Innes Chambers are public-private spaces, and it is in this central portion of the building that the raked auditorium is situated. Its creation required the partial demolition of existing 1st and 2nd floor slabs, but the new suspended concrete auditorium roof forms an outdoor garden atrium which functions as a pause area, consisting of two deck zones and a section of soft landscaping. An undulating Hunter Douglas slatted timber ceiling has been installed throughout the areas and congregation spaces, including the auditorium, along the north end edge of the building.
Delta Softline 1200x600 T5 ceiling tiles, chosen for their efficiency and top quality indirect light, illuminate the offices, which make up most of the building (from the third to the 11th floor), the meeting rooms and boardrooms. Installing suitable lighting for the ceiling presented more of a challenge. Architect Leane Fernandes of Activate Architects explains that to present the ceiling to best effect she and Glen Kwasnik of KKA Consulting Engineers wanted more than a standard downlight. Catherine Feher of Regent Lighting suggested a combination of Linear Micro LED and Linear Maxi T5 fixtures. The Linear Micro, which offers 24 W/m at 4000 K was slim enough and able to be custom sized to fit between the wooden ceiling cladding.
Further, custom made brackets allowed the fittings to be clipped on, giving access to the services which are installed above the ceiling. After much consultation with Kwasnik and the contractor on site, standard T5 Maxi Linears were used for the auditorium. These abutted each other, with the 1st fitting in the row designed and manufactured with a special access hatch, a 300 mm long compartment within the fitting, to allow the contractor to connect
from the main services, which were supplied through the centre of the auditorium. The common areas of the building are illuminated by 18 W and 26 W Perox downlighters.
The effect of the lighting fittings on the warm undulating timber ceiling is appealing and blends well into the existing space and architecture. The exterior of the building was not illuminated because of historical conservation concerns but inside light shines through the Y-shaped façade to create a pleasing night time effect, lighting up what was a dark section of the city and restoring Innes Chambers to landmark status in downtown Johannesburg.
Article: Lighting in Design
Acknowledgements to: Leane Fernandes: Activate
Architects; Catherine Feher, Regent Lighting Solutions;
Brian McKechnie: http://www.theheritageportal.co.za;
Glen Kwasnik: KKA Consulting Engineers