Old Parliament House in Canberra, which now houses the Museum of Australian Democracy, has a special display devoted to Australia’s prime ministers.

The display features a portrait of each of the 29 people who have held our country’s top job. Alongside each, there are a series of brief points about the major achievements of each prime minister while they were in office.

With the recent transition from Tony Abbott to Malcolm Turnbull, the political spotlight has, for a brief period, focused on what Mr Abbott’s legacy in the top job will be. His administration spent much of its initial period in office following the 2013 election honouring promises to wind back Labor policies, such as the carbon tax and the mining tax. There was also the introduction of a rigid border protection regime which stopped the passage of illegal asylum-seekers to Australia and this was arguably Mr Abbott’s most significant achievement.

However, there was another ground-breaking move the Coalition Government made under Mr Abbott which has the potential to, perhaps, be his greatest legacy – even though it hasn’t attracted anywhere near the same level of publicity as the other measures mentioned above.

In April 2014, Mr Abbott announced that Badgerys Creek, some 50km west of the centre of the city, would be the site of a second major airport in Sydney. After decades of governments at both federal and state level considering (and arguing over) many different sites – even Canberra Airport linked to Sydney with a very fast train was considered – a decision had finally been made.

At the time of the announcement, the federal government spruiked the economic benefits for western Sydney of a new airport at Badgerys Creek, including the creation of 60,000 jobs once the airport is fully operational, with construction to build the airport expected to start in 2016 at a total estimated cost of $2.5 billion.

There were mixed feelings among local federal MPs about the announcement. While most welcomed it, many also harboured concerns about aircraft noise and increased traffic congestion. It set the scene for what could have been a controversial period following Mr Abbott’s announcement. But this wasn’t the case.

If, indeed, a second Sydney airport is successfully built at Badgerys Creek, then Mr Abbott will be able to claim a lot of credit for this. Given how significant this will be, it’s probably surprising that he didn’t spend more time publicly talking up the benefits of the airport when he was prime minister. It will be interesting to see if or how it appears alongside his portrait in the display of prime ministers at Old Parliament House.

– By Hamish Arthur