Wesley Place is a vibrant new workplace destination with three commercial towers rising from this historic precinct. Seamlessly merging business and lifestyle, the precinct comprises the recently completed premium commercial tower, 130 Lonsdale Street, one of Australia’s smartest buildings with 55,000m2 of premium-grade office across 35 levels and four skyrise terraces.

130 Lonsdale Street is the flagship tower for Wesley Place, with the new 140 Lonsdale Street tower and 150 Lonsdale Street refurbished tower nearing completion. The 1.1-hectare site offers Melbourne a new and rare green public CBD space surrounded by the restoration of historic buildings such as its namesake Wesley Church.

Charter Hall engaged AECOM to provide structural, civil and geotechnical services for the entire precinct.

Site challenges

AECOM was presented with a structural and buildability challenge. The excavation of the new basements essentially formed an island around the existing heritage Manse building, and the tower design required 30 new levels constructed directly on top. AECOM responded with an innovative engineering solution to construct a protection deck and steel truss to transfer 5,500t of load and bridge the 25m clear span. These works were monitored by AECOM’s Acoustic team to ensure no risk of damage to the heritage building.

Excavating in the CBD was challenging due to adjacent and simultaneous excavations, neighbour concerns, peer review, and risks to the heritage buildings. Recognising the challenge, Lendlease engaged AECOM’s geotechnical team to provide full design services for the site retention. This value-add, AECOM structural-geotechnical joint approach, was pivotal in enabling a timely and coordinated structural design in a high-pressure situation.

The Raking façade and 2-column grid

The façade rakes out up to five metres and conventional practice would be to rake the columns to match. Raking columns result in expensive floors with reduced flexibility for large atrium voids. AECOM provided an alternative 12m x 16m ‘2-column grid’ where straight columns were placed inboard to the façade and cantilevers were deployed to form the building rake.

Our alternative solution reduced column numbers, simplified the structure, increased tenant flexibility and simplified the built form.

Maximising Net Lettable Area (NLA)

With a Gross Floor Area of 85,000m2, the core has the single largest impact to NLA. Multiple core configurations were presented and rigorously tested by AECOM for its overall building footprint including:

  • Geometric configurations – 3 or 4 bank lift shafts.
  • Efficient assignment of wall thicknesses. For every 100mm reduction we achieved in the main wall, over 100m2 of NLA was released through the tower.
  • Strategically amended wall thicknesses up the tower to coincide with key jump-form changes yielding an additional 3m2 of NLA per floor essentially, at nil cost.
  • We also challenged services risers and worked with the Mechanical Electrical Plumbing team to relocate risers from the floors into the core which increased the NLA.

Tenant Flexibility

Charter Hall proceeded with the design and construction of Wesley Place with full confidence of signing tenants as the tower emerged. Tenant flexibility was therefore critical in our structural design. In our tenant-centric approach we unbound ourselves from standard carpark grids and let the typical floor drive the design. This grid provides enhanced flexibility as evident with the tenants opting for inter-tenancy voids of 80m2 with minimal impact to the structural framing. AECOM were also engaged to provide full integrated fitout for tenants where winter gardens and terrace zones were provided with the base build.

Value-add approach

  • Be agile, collaborate and receptive to new ideas. During the unusual protection works period all ideas were considered with multiple structural systems tested, designed and certified.
  • Access to international expertise and multi-disciplines can add value at short notice. Engagement of our geotechnical and vibration teams provided timely and comprehensive advice during protection works notices.
  • Innovation through design. Exploring alternative design solutions through systemised technology, parametric optimisation and digital engineering – ‘Beyond BIM’
  • Extensive experience as leaders in the commercial sector. Sharing ideas from previous projects is ingrained in our culture. The lessons from our 80 Collins Street transfer trusses were successfully applied to the Manse transfer truss.