It's not difficult to see the appeal of the sustainable vision presented by global 'starchitects' Foster & Partners at a recent infrastructure conference in Hong Kong, with funky white automobiles zipping on autopilot along underground magnetic tracks around a pristine city of trees raising long green limbs and men wearing long flowing robes. For Foster & Partners, well known locally for the HSBC headquarters and the Hong Kong International Airport, the foundation of sustainable engineering takes a step back from tradition. As associate partner Randy Liekenjie says: 'Buildings are just the tip of the iceberg,' with infrastructure, transport and sustainability built deep into Foster projects through, for example, the choice of materials, the manipulation of sunlight and building orientation, and the use of natural ventilation and wind towers for urban space. But while engineers, architects and designers may well have utopian visions of our cities and future society, implementing them will require some serious challenges to the ways engineering projects are commissioned, designed and built. According to many in the trade, the current practice simply isn't sustainable. 'Government briefs tend to show a lack of understanding of what sustainability actually means,' says Fiona Waters, principal economist at PricewaterhouseCoopers (PwC). She cites the lack of 'joined-up thinking' between sustainable engineering and infrastructure, partly due to the structure of public finance: One-off projects are covered by the Capital Works Reserve Fund (CWRF), while recurrent and operating expenses come from current accounts. 'The government is very comfortable about one-off capital projects,' says Roger Nissim, adjunct professor at the real estate and construction department of the University of Hong Kong. 'But it's far less comfortable creating recurrent expenditure.' This leads to an imbalance in priorities, says Waters. 'What tends to happen in the [CWRF] is there is a total focus on the building, how much is spent, the design, but very few questions tend to be asked about the operational side,' she adds. As such, the 'software' of the city - the fabric, connections and services between buildings - is neglected, creating a serious sustainability challenge as the population expands. As Nissim notes, Hong Kong will be home to two million more people by 2039. 'A lot more needs to be done on the software side to make it comfortable for us who are already here, let alone to handle the population growth,' he says. Another major weakness in the promotion of 'joined-up thinking' stems from archaic contracting process that promotes building first and asking questions later. This leaves too much power in the hands of digger-happy engineers, Nissim says. 'Too many of these decisions are engineering-led, and there is a presumption that once they are presented to the public, they are going to go ahead whatever,' he says. 'A lot of this has to be done earlier in the design stage. Often, by the time it gets to the contract stage, there is very little we can do,' says Brian Gillon, operations manager for Leighton Asia. More innovative contracts - such as Leighton's recent 'design-construct' deal for the US$4.7-billion (HK$36.7 billion) sludge treatment facility in west New Territories - offer more flexibility. Newer contract styles can give the contractors significantly more scope to change designs due to changing situations or unforeseen factors, such as public hostility. Such flexibility may require wider skills and there are signs engineering education is broadening accordingly. 'There has been a tendency to broaden the scope of the training to include a second discipline,' says Gillon, adding that students can study an environmental or law degree alongside engineering. Such flexibility will be a useful addition to engineers' CVs. The government's penchant for huge projects may create exciting opportunities for engineers in the short term, but it can cause career difficulties down the road. 'It creates a boom-and-bust mentality,' says Gillon. 'This cycle is not unusual in the construction industry, [but] people want to know there is a long-term plan to their careers.'