24 March 2011 – Case Study: According to mySmart CTI, a Sydney-based company that provides energy efficiency solutions, refurbishment of an art deco heritage building at 99 Macquarie Street in Sydney showed that it was possible to provide the building with a modern and sustainable lighting system while preserving the heritage listed building interior.

Situated in Sydney’s busy CBD, 99 Macquarie Street is a heritage listed art deco landmark, home to Mulpha Australia Limited and other tenants including M&C Saatchi and the JB Fairfax-related Cambooya and Marinya Media entities.

Rich with local history, it was constructed in 1938 as the home for the former Department of Motor Transport and Tramways. It was considered cutting-edge with striking architectural design features.  Constructed primarily of sandstone the exterior has now been extensively refurbished to its original glory but with the interior now featuring stylish and modern workspaces. The building needed an innovative solution to address its changing lighting requirements: a scheme that would support the interior modern workspaces whilst not compromising the restored glory of its sandstone exterior.

According to mySmart CTI,  whose services include building system and lighting controls and metering and reporting,the challenge was to ensure no damage occurred to the existing fabric during the installation of the new lighting system.

New bulkheads were built to accommodate the infrastructure for building services; however in other heritage-designated areas this was not possible and those areas required use of existing conduit in the concrete slab floors.

In order to overcome these obstacles, mySmart CTI engineered a solution that incorporated two lighting control systems – DSI and a DALI/C-Bus combination – which used minimal cabling over seven floors but maximised functionality.  DSI was predominantly used throughout the building with the exception of levels three and five.

The Commissioner’s Room on level five was cabled via existing conduit in the ceiling as was the lift lobby on both level five and three. In these areas DALI was incorporated using a C-Bus gateway to control the lighting without compromising the interior surfaces.

These two systems were evaluated as the best solution to control the light fitting with minimal control cables as existing conduits had to be used.  The system allows all switches and sensors to reside on one cable; and utilises “daylight harvesting” with photoelectric cells providing perimeter lighting.

A unique feature of the refurbishment was the Frenger light fitting The fitting incorporates the fire sprinkler system as well as the primary air conditioning, which again reduced the impact of services on the building’s internal structure.

The initial multi-network “base-building” design created a platform which led to easy integration of the lighting control system for tenants.  The user interface is simple to use – the building manager has total control of the lighting using a touch screen control, which automatically lighting on or off on each floor at designated times, rather than lights remaining constantly on, maximising energy efficiency. The building manager can also easily adjust scheduled times to cater for tenant operating hours.

The project required a large amount of careful strategic integration with all services, the heritage architect and the heritage office.

The use of DALI and DSI was the best option to control the light fitting with minimal control cables as existing conduits had to be used.  Using a simple Bus system meant all switches and sensors could reside on one cable, again using minimal conduit real estate

While retrofitting a heritage listed building such as this one can be complicated and detailed, the benefits of having modern lighting systems are tangible – being able to control lighting based on occupancy, rather than having lights on all time significantly reduces energy use and leads to demonstrable cost savings.  As a greater number of listed buildings consider their energy efficiency, these types of programs look set to become more common.

This case study was compiled with the assistance of material provided by mySmart CTI