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 The redevelopment of the 1867 Heritage-listed Melbourne architectural icon Melbourne GPO is an exciting project, currently in progress. The nineteenth century structure is preserved in the facades facing the Bourke Street mall and Elizabeth Street, while the interior will reflect a grand, belle époque atmosphere enhancing the fashionable boutiques and shop tenancies planned for the site. This development follows an earlier approved proposal to convert this historic building into a five-star hotel that did not proceed. A post office has existed on this site since 1841. The present building was constructed in three stages between 1859 - 1907, all to the design of A E Johnson. The third level and tower were added in 1887. One of Melbourne's exceptional group of Victorian public buildings, it is a building that has been of great social and civic consequence to Melburnians since its construction.
The current development is based around a specialist retail and office conversion, involving the full adaptation and thoughtful integration of the main heritage registered building together with carefully crafted additional built elements. When opened back in 1867, post office customers were served from openings onto the Elizabeth Street colonnade, while the building itself was filled with clerks. A Walter Burley Griffin renovation in the early 20th Century opened the GPO to the public for the first time, but the building itself retained a fusty atmosphere with cubicle offices and drawn blinds. Now, there will be a transparent and open complex with a natural light filled interior to show the original building in all its glory. The public will be served with cafes spilling, Venetian-style, on to the Elizabeth Street colonnade and to Postal Lane to the east. The opening of Postal Lane will create the first lane link from the Bourke Street mall through to Little Bourke Street. The project also involves the revitalisation of significant external public spaces in the heart of Melbourne City, contributing an urban response to one of Australia's most prominent buildings.
The historic building was extensively damaged by fire in September 2001 and the first stage of the $20 million project has involved reinstatement of the heritage-listed postal hall to its original condition. This stage has included the reconstruction of the original four-storey postal atrium that adorns this late Victorian building and restoration of the ornate ceilings. Materials used on the principal facades of the existing building include extensive areas of Tasmanian sandstone, and Gabo Island granite. Notable features used widely on the building exterior include the elaborate design and high standard of finish to stone rendered surfaces.
Heritage restoration award-winner, St Hilliers, was contracted by Australia Post to complete the reinstatement. St Hilliers is also principal contractor for the new building stage for the developer, MGPO Pty Ltd.
 "We are delighted to be working with Australia Post and MGPO Pty Ltd to rejuvenate this spectacular Melbourne icon that will, in conjunction with the new retail and commercial space, continue its role as an important element in the city fabric, " said Tim Casey, Group Managing Director of St Hilliers.
A new six-level building housing restaurants, shops, offices, along with the mechanical and electrical services with the street-facing facades to Little Bourke and Elizabeth Streets, and connecting with the original GPO structure is part of the overall project. The new building although connecting traffic and services with its historic partner, is structurally separate so as not to impact the structural integrity of the original structure. Constructed almost entirely out of precast components, the new structure has approximately 2300 square metres of hollow-core plank floor area. Hollow-core planks make sliding contact with the steel structure of the old building ensuring that the two building components are entirely separate structurally.
The new building will have all-glass exteriors to contrast with the original Post Office, rather than slavishly copy the original. It is a contemporary addition that is functional, sustainable, sympathetic and deferential to the heritage character and urban context, aesthetically pleasing and architecturally challenging while being significant. The structure was originally conceived as in-situ concrete construction because of the architectural requirement of cantilevers on three sides and the lack of wall panels to provide structural rigidity. St Hilliers and consulting engineers, Arup, in conjunction with Hollow Core Concrete Pty. Ltd. decided prior to the commencement of the project that there would be considerable advantages to the use of pre-cast components. Hollow Core recommended appropriate construction techniques, which were accepted by the project team. Hollow Core has provided the majority of the precast components required for the project, including precast columns, beams, hollow core planks, solid cantilevered planks and lift panels for the new building as well as the stair panels and stair flights for the original building
 St Hilliers cites speed of construction and the rapid access available to following trades as the major advantages for using precast components. Overall, some six weeks in time has been saved and this could have been higher but for unavoidable design requirements. Hollow Core highlighted additional features of the building design that could benefit from the use hollow core planks. As the architectural design calls for angled, cantilevered terrace and floor sections facing both Elizabeth Street and Little Bourke Street, a solution was found in the use of solid cantilever sections cantilevering from the precast beams. Structural rigidity was obtained by providing a precast moment frame at the Elizabeth Street end of the building.
Contrary to the perception that hollow core planks cannot have cut-outs and that the use of this method of construction limits architectural design, the company was able to show at the GPO site the versatility of the material. The design required a change to the location of the air conditioning plant, which necessitated the drilling of 200mm diameter holes in the planks on a 1200mm grid.
The construction method is said to be economical in terms of material and labour costs. Savings relative to on-site concrete pour construction varies depending on the building design and functionality required. As an estimate, though, savings can be 15% of on-site concrete pour costs.
The OutcomesThe building's heritage is its main asset. A feature of the restoration is extensive use of light reflective paint that lightens and opens up the old postal hall and floors above. The colour of the paint, plus the expansive use of glass and stainless steel, is designed to complement the beauty of the original building. The redevelopment, for which MGPO holds a 99-year lease, includes a full fit out to ground floor retail areas in the GPO and an upper level day spa. The adjoining new building also features a restaurant on the top floor. Refurbishment is now completed and the current construction works are showing that the resulting refurbishment is outstanding, marking a shift from slavish heritage restorations of the past. The GPO Melbourne will continue to be a meeting place, embraced by all Melbournians, who have gained an important architectural city intervention.  Project Team
Client: Wetherby Capital
Project Manager: Baracon Group
Architects: Williams Boag
Engineers: Arup
Construction and Refurbishment: St Hilliers For further information on the hollow-core construction system, contact: Hollow Core Concrete Pty Ltd, Ph 03 9369 4944 |