Custom integrated FacadeXS solutions for the Collins Arch

In a city with a growing amount of high-rise constructions it can be hard to distinguish a buildings design from the surrounding ones. Architects will do anything to make their design outshine all others.

Located at the addresses of 433 to 439 Collins Street in Melbourne Victoria, the design of Collins Arch is an example. This stunning building is designed by the architectural firms Woods Bagot and SHoP Architects and is currently under construction by long-term XSPlatforms client Multiplex. Multiplex and XSPlatforms have collaborated before in multiple Australian landmark projects such as 50 Martin Place and the Hyatt Regency in Sydney and the Crown Hotel in Perth.

Upon completion in 2019 Collins Arch is set to reach a total height of approx. 157 meters (515 feet) and will house over 200 luxury apartments for residential purposes in both the East and West Towers. These towers are connected via a Skybridge located at level 34. Collins Arch will also include a five-star hotel, approximately 50,000 square meters (538,000 square feet) of commercial (office) space and ground floor retail.

A building of this proportion and design brings several challenges when it comes to facade access. XSPlatforms took these challenges and converted them into a total of four custom FacadeXS solutions, three types of roof cars and one self-hoisting monorail solution.

West Tower

Two of the four so called Building Maintenance Units (BMU) for this project are located on and in the West Tower. Both solutions involve traversing roof cars which can be (party or completely) hidden out of sight when not in use.

BMU 01

The first of two FacadeXS solutions on the West Tower is located on level 40/41 at approximately 150 meters (492 feet) high. This 4-stage telescopic roof car traverses along a 76 meter (249 feet) track lay-out which assures that this BMU can reach the designated parts of this towers facade.

International Partnership

“Collins Arch is the culmination of an international partnership between thought leaders in architecture, construction and real estate. Working together to redefine the Melbourne skyline, the team has created a vision for the site of rare beauty, a daring design for a new era in Melbourne’s history.” Source:

In order to provide maximum access this roof car is equipped with a special cradle that can manually be extended in width before making a drop along the facade. The standard width size of the gondola can be elongated with approximately 1.8 meters (6 feet), making up for a total width of 5 meters (16 feet). As described in an earlier blog article about cleaning cycles, a wider type of gondola means that fewer drops need to be made. This comes to benefit the amount of time that is needed to clean the facade, the so called cleaning cycle.

Also incorporated into BMU 01 is the option to replace glass panels if damaged or broken. To ensure that recessed parts of the glass facade can also reached, a telescopic GRU balancer is applied. The balancer can be adjusted in reach so that it can bring a glass replacement tool, for example a glass vacuum lifter, closer to the facade.

Last but not least, this roof car can be traversed into a specially designed BMU garage. Providing window washers or other maintenance personnel with the option to park the BMU out of sight when not in use.

Features of BMU 01 on the West Tower

  • Traversing telescopic roof car.
  • Telescopic jib with a max. outreach of approx. 40 m (131 ft).
  • Maximum luffing angle of 17.5 degrees.
  • Traversing along a 76 m (249 ft) rail track.
  • Parking in a specially designed BMU garage; hidden out of sight when not in use.
  • Width adjustable gondola with a max. width of 5 m (16 ft)
  • Equipped with a Glass Replacement Unit (GRU) with a max. load of 800 kg (1763 lbs).
    • Includes a telescopic GRU balancer for recessed facade areas.
  • total wire rope length: 150 m (492 ft).

BMU 02

Several levels below BMU 01, another roof car is located. On the south terrace on level 28 of the West Tower we opted for another traversing roof car, but this time one with a fixed jib length.

What makes this unit special compared to others is its ability to lift the jib at an angle of up to 66 degrees from the horizontal. This ensures that the cradle can be positioned at each location of the designated facade parts for this BMU.

Although this roof car cannot be parked inside the building, when the jib is topped down in a horizontal position, the slightly raised parapet helps hide the BMU when inactive.

Features of BMU 02 on the West Tower

  • Traversing roof car with a fixed jib.
  • Fixed jib with outreach of approx. 15 m (49 ft).
  • Maximum luffing angle of 66 degrees.
  • Traversing along a 31 m (101.7 ft) rail track.
  • Equipped with a Glass Replacement Unit (GRU) with a max. load of 600 kg (1322 lbs).
    • Includes a GRU balancer for recessed facade areas.
  • total wire rope length: 110 m (360 ft).

East Tower

The third solution is located on the level 16 terrace of the East Tower and is a more distinctive roof car when you compare it to the others. This BMU is characterized by its knuckle-jib function which makes it possible for the cradle to access facade parts which are located around a corner. When fully extending all three stages of this knuckle-jib, the roof car will have a maximum outreach of approximately 17 meters (56 feet). When combining a knuckle-jib and traversing undercarriage we can make sure that it provides full access to all designated facade elements for this BMU.

Similar to BMU 01 (West Tower), this roof car can be fully integrated into the building when not in use. The three stages of the jib will be retracted, or folded in as you might say, and the BMU will be traversed into a BMU garage.

Features of BMU 03 on the East Tower

  • Traversing knuckle-jib roof car.
  • 3-stage knuckle-jib with a max. outreach of approx. 17 m (56 ft).
  • Traversing along a 11 m (36 ft) rail track.
  • If not in use, this unit is fully folded and parked inside the building.
  • Equipped with a Glass Replacement Unit (GRU) with a max. load of 300 kg (661 lbs).
  • total wire rope length: 60 m (197 ft).


The skybridge connects the East and West Tower at level 34, approximately 132 meter (433 feet) above ground level. In order to reach the facades of the skybridge, in combination with the lower situated facade parts of the building, XSPlatforms offered a solution using a single monorail system. Combined with a traversing self-hoisting gondola all inner parts can be reached without having to switch from system. A dedicated BMU garage guarantees that this solution can also be parked out of sight for the residents, hotel guests and general public when not in use.

Download our project leaflet for Collins Arch, by clicking the button below.