Innovative design brings efficient solutions to HVAC system for this prestigious project.


  • Midrand, Gauteng, South Africa

Project Value

  • ZAR 1.5 billion, total project value

Project Status

  • Completed

The Tower in Waterfall, located in Midrand, is the new headquarters building for PwC in South Africa. Owned by Attacq and developed by Atterbury, the R1.5 billion Tower is the first high-rise building developed within the booming Waterfall precinct, as well as the Midrand-Kyalami district. 

The Tower is an iconic 27 storey building that comprises 25 storeys of modern office space, five parking basements, designed to house 3 500 PwC employees in an efficient and optimally designed workplace. The headquarters also includes an annexure building onsite that comprises of numerous office floors, conference facilities, meeting rooms, commercial kitchen and canteen facility, recording studio, and archive rooms. The total development is around 48,000m2.

Developed in a prime location, the Tower overlooks the Waterfall City Part and the Mall of Africa. With its unique design, the height of the Tower and the fact that it is situated on a high point in Waterfall make it the tallest structure on the corridor between the Sandton and Pretoria/Tshwane CBDs.

Visible from almost anywhere within a 30km radius, the Tower gently twists through in height with the top and ground floors rotated by 30 degrees – framing the grand urban park, which forms the green heart of Waterfall. The Tower has also been designed to conform to the internationally recognised LEED (Leadership in Energy and Environmental Design) silver standard. LEED is a set of rating systems for the design, construction, operation, and maintenance of green buildings, homes and neighbourhoods.

WSP was appointed as the mechanical consulting engineer on this project for heating, HVAC design, building management systems (BMS), as well as energy monitoring systems (EMS).

The air conditioning for this building has been designed to be commercially economical, while maintaining good occupancy comfort and thermal zoning. This has been achieved through high operational efficiency, and high coefficient performance (COPs) of the cooling and heating systems, with state-of-the-art chillers and an integrated heating and cooling recovery system.

27 27
Total space
48,000m2 48,000m2
3,500 3,500

PWC Tower, in Waterfall, Midrand

System description

The air-conditioning system comprises of a central cooling and heating system. Chilled water is generated onsite by a combination of two state-of-the-art high-efficiency water cooled Carrier screw chillers, three multifunctional air-cooled chillers and one heat pump chiller. The six chillers work in combination to provide the best energy efficiency and lowest water consumption, depending on the cooling demand and the ambient temperature conditions. 

Chilled water is pumped via primary and secondary pumps to various fan coil units (FCUs) and air handing units (AHUs) in insulated steel piping. No electrical heating is installed anywhere in the HVAC system, as this is very inefficient and environmentally unfriendly. 

For the design, careful consideration was given to ensure the complete HVAC systems was easy to operate and maintain, with good HVAC system reliability and long service lifespan. Though we also incorporate good service access to all the HVAC equipment – as it was essential that all components of the HVAC system can be accessed easily and safely.
Pieter de Bod Technical Director, WSP, Building Services, Afric

Special features

Some of the special features of integrated heating and cooling system include:

  • Most AHUs in the building include a night-time flushing mode, as an energy-saving feature to allow internal spaces to be ventilated and cooled with outside air overnight. 
  • Automated blind system that is linked to solar sensors, which will automatically open or close blinds depending on the angle of the sun and the time of day. This system has been designed to incorporate glare control and minimise solar influx into the building. 
  • Low-pressure hot water heating system incorporated in the footwells of the reception desks, and underfloor hot water hearing installed in the main lobby in the ground floor slab – to make these spaces more comfortable for occupants. 
  • The parking basements are mechanically ventilated with large axial fans, connected to the smoke detection system and carbon monoxide (CO) sensor system.
  • The building monitoring system (BMS) monitors the building’s HVAC systems, generators, UPS, main electrical meters, main water meters, and fire detection system alarms. All the information is transmitted to a central computer in the control room, where it can be securely accessed and assessed remotely – and the BMS can be set to trend and store data for troubleshooting purposes. 
  • The energy monitoring system (EMS) dashboard was also designed by WSP – to display, monitor, and record the electrical and domestic water consumption on the project, to understand the consumption patterns of the large electrical and water consumption components, and to manage this.