Westfield Group’s $1.2 billion Westfield Sydney redevelopment project kicked off with a bang when the first stage opened to the public at the end of October last year.
Opening six months ahead of schedule, the impressive shopping centre in Sydney’s CBD launched with 130 fashion and food specialty stores, with a further 120 opening over the next year or so.
The project also involves the open ing of a 25-storey commercial tower at 85 Castlereagh St in 2012, part of an office component comprising around 76,500 sqm across three buildings on Castlereagh and Market Streets.
One of these buildings - the 100 Market St commercial tower - is Australia’s largest 6 Star - Green Star Office Design v2 certified refurbish ment, the highest rating achievable.
In order to make the project as impressive as possible, both in terms of design and sustainability, a number of factors had to be considered, not least of which was the many different finishes used both internally and externally.
After winning an international design competition, John Wardle Architects was in charge of Westfield Sydney’s commercial towers and external building design which included all street frontages for Castlereagh, Market and Pitt Streets, public entries, laneways, awnings and footbridges.
Glass is being used extensively throughout the project both for aes thetic and sustainability reasons.
The project’s awnings are made from glass and John Wardle from John Wardle Architects is particularly happy with their innovative design.
“We look very critically around Sydney, as we do around Melbourne, and see that glass canopies are good. They allow transparency to other areas and they don’t overwhelm the foot path by having a heavy lid over it, so glass is a great material for a canopy.
“However, it tends to show dirt very quickly. So this frit pattern was developed. It’s a ceramic frit baked onto the glass so it’s there forever, and it’s an interesting pattern. It’s Lomandra Multiflora, which is an Indigenous grass of Sydney and ... it was actually used by the local aborigi nal population for basket making, so we thought that was an interesting association with retail,” he said.
Glass was also used for the curtain wall facade of 100 Market St and is being used in the same way at 85 Castlereagh St. This type of applica tion improves the building's energy efficiency by increasing the amount of natural light entering the building, says Stefan Mee, principal at John Wardle Architects.
“The performance of the curtain wall is paramount to these types of projects, and you’re wanting to max imise your daylight into each floor whilst preventing glare and also keep ing your heat load down,” he explains. “But balancing all those things and getting the best balance is one of the key challenges, so I think we've managed to achieve a pretty good outcome in that respect.”
Increasing the amount of light in the buildings was achieved by extend ing the floor plate.
“We took the surgeon’s knife to the floor plate. We extended out on the corners a little to improve the build ing’s relationship to the street and views, but then also cut into the floor plate to create naturally lit light wells and they've had a huge impact in terms of improving the amenity of the floor plate,” Mee explains.
Despite the project's modern design and the innovative use of building materials such as glass and zinc, timber will be one of the most important materials used at Westfield.
“One of the key finishes that we’ve used in the lobbies for the main tower is timber,” Mee continues. “So basically it’s a locally sourced timber. We looked at a range of different tim ber sources from around the world but in the end we thought that using a local timber would help to reduce the carbon footprint significantly.”
The timber was sourced from man aged forests in NSW and Victoria and was used in what Mee refers to as “an interesting batten custom profile sys tem that runs all the way through from the street up to the sky lobby level (level 7)”.
The detailed timber battens go from the lobby on level 7 and come down to the ground level lobby at 85 Castlereagh St. They then come out to the outer facade of the building, where the battens’ material changes from timber to sandstone.
“Sydney is very keen on the imple mentation of local sandstone and so we looked at its use, at some of the most interesting details of many of the other buildings in the precinct, and saw the opportunity to have this way of sculpting the sandstone, par ticularly where it was celebrating an entry. So we hope it's both contempo rary and has a sympathetic reflection on the materials of the city,” says John Wardle.
Wardle is also particularly pleased with the development's new foot bridges, replacing the heavy, double width concrete bridges created in the 1970s. The new bridges not only modernise the whole project, but also allowed for repairs to be made on the iconic David Jones building.
“Entirely new bridges were created - double-storey,” he says. “Two bridges were removed from Pitt St mall and one single double-storey bridge created. The very broad, heavy concrete bridges that crossed Market and Castlereagh Streets were removed and replaced with these slender, transparent, highly articulate bridges that cross all three streets.
“What is particularly good is that it allowed us to repair some of the dam age that had been done by previous bridges. The previous bridges were very unsympathetic to their attach ment to the beautiful old David Jones sandstone facade on Castlereagh St and the quite finely detailed brick facade on Market St. We actually aligned these bridges with the original window patterns and they’re much narrower, so we were able to restore the whole areas of the facade on both buildings. That was a really good out come.”
The bridges are made from “amaz ingly sophisticated” steel and glass engineered to “amazing thinness,” Wardle explains. "With a very shallow concrete deck over the top and fibre glass reinforced panels for the under side. They’re as slender and as trans parent and as direct as could be designed. You can see the double height bridge on Pitt St mall has this overlay of the upper level, glass drapes down over the lower level, so it's quite a nice, subtle detail and you actually see the glass free of any other structure. Just free floating glass, which is quite a strong detail.”
With the project’s completion due in early 2012, Westfield Sydney is expected to offer the next generation in Australian retail, delivering a world-class shopping, lifestyle and dining experience. Its architecture and design will also deliver an impres sive and innovative combination of modern day and tried-and-tested building products and facades that not only make the project aesthetical ly pleasing, but environmentally conscious as well.
