Ecca collection

During earlier construction work in the area, all of which has been recently developed, the contractor took the client up on to the roof of another building to see the view, explained Chad Brown, principal and project architect at Thomson Adsett. It proved to be magnificent. ‘This was the catalyst to the height and form of the new building,’ Brown explained. ‘We asked, what is the most efficient maximum height to give staff 360 degree views that take in the central business district, and views along the river and back to the city?’

The solution was a curvaceous white building, cantilevering over a central core with those cantilevers supported on stilts. Fisherman’s Island, where the development sits, has very little public transport, so almost all employees drive resulting, too often, in buildings surrounded by a sea of parking. At the port building, the architect was able to reduce this effect by placing much of the parking beneath the building. It then created its three layers of office accommodation, complete with balconies, and a shaded roof deck on top from which to enjoy the views. So attractive has this proved to be that, although initially intended for the employees in the building, it is shortly to become publicly accessible.

The form was a departure for the architect, which normally goes for more rectilinear designs rather than the buxom layer cake that it has ended up with here. The curves, said Brown, ‘came from looking at the most efficient form for an office. That was a circular shape around a central core.’ But then the architect wanted to squash this, to emphasise the east-west axis, so that as much space as possible faced either north or south – the easier directions from which to provide solar shading.  The office space itself is almost rectangular, for ease of space planning, with most of the curves provided by the balconies. These have a double function – to provide immediately accessible outdoor space for impromptu meetings or quiet study, and to provide solar shading.

The balconies, the most visible part of the building, are clad in prepainted metal in a standard white colour. One of the reasons that the architect chose this material was because of its durability – it is only 600m from the waterfront and so vulnerable to salt spray. The choice of colour, said Brown, was ‘because I always like to have the form of the building do the work – it allows us to have a simple palette of materials.’ There are some elements of fibre-cement on the building, and Brown was struck by the superior quality of the prepainted metal, ALUCOBOND® White 16 by 3A Composites. ‘It captures the light, and changes from day to day,’ he said. Indeed the building sprang a pleasant surprise on him, turning a wonderful orange colour in the evenings as it reflects the setting sun, and maintaining an orangey hue throughout the night, thanks to the nearby street lights.

The building was designed to achieve five stars in Australia’s Green Star rating system (its equivalent to the US LEED and UK’s BREEAM). This is one below the highest level and required a total score of 60 points out of 100. It is seen as representing the best of Australian practice, whereas a six-star building would represent the best of international practice.

The building has a concrete frame, and replacing some of the cement with fly ash was one of the major environmental moves. Also, the reinforcement uses a high proportion of post-consumer recycled steel. Friction piles support the building, and since they are not all the same length, the tops had to be cut off some of them. The contractor, on its own initiative, broke these up and used them as footings for pile caps. The pre-cast concrete columns that support the cantilever of the first floor are hollow spun columns, a method which cuts down on the amount of material used.

The other great environmental saving comes from the fact that the building uses fresh air throughout, something that is made possible by the balconies and also by the fact that the atrium functions as a thermal chimney, with hot air rising and being vented through the stack effect. This atrium has a second function – it is part of an unusual fire strategy, playing the key role in smoke management. Effectively, the mechanical ventilation system will function in reverse. In case of a fire the atrium roof will slide open, and smoke will be drawn to the atrium and extracted at the top.

As with all buildings that have high environmental aspirations, one must not lose sight of the fact that the most important issue is to make it a pleasant place to occupy. With abundant natural light and plenty of shade, not to mention the views, this is an aspiration that the Port of Brisbane building certainly satisfies.