The prime task of the commission was to develop the Register of the National Estate, which had more than 13,000 listings when the commission was abolished by the Howard government in 2003. “We collectively reached the view that the only way to avoid bias in listing caused by temporarily prevailing architectural likes and dislikes, was to seek to list the best examples of each style period,” Professor Yencken writes. He says whether or not they enjoyed architectural popularity at the time, the likelihood was that the heritage significance of each would almost certainly be better appreciated at some time in the future. Urban historian Graeme Davison says Professor Yencken is a “national treasure”. “I can’t think of anybody who has contributed more to our understanding about the Australian environment than he has.” Urban historian Graeme Davison says Professor Yencken transformed Southbank. Credit:Eddie Jim

Professor Davison met Professor Yencken at a party when he was secretary of the Victorian Planning Ministry from 1982 to 1987. They talked all night. “I thought this is a most remarkable person - he had a breadth of vision, a capacity to think imaginatively and creatively.” Professor Yencken contributed to the re-imagination of Melbourne. In 1985 Swanston Street was a gloomy, car-clogged thoroughfare. As part of Victoria’s 150th celebrations, Professor Yencken had the radical idea of turning it into a giant green pop-up park. Professor Yencken turned Swanston Street into a green pedestrian mall as part of Victoria's 150th celebrations. Credit:The Age For the weekend of 9 and 10 February, 13,250 square metres of fresh grass was rolled out along four blocks of Swanston Street.

The price tag for the party - $550,000 - was not cheap. Professor Yencken’s wife - Dr Helen Sykes - recalls a friend sniping “this is my taxes at work”. Premier John Cain wobbled after a sustained attack from then opposition leader Jeff Kennett. He rang and asked Professor Yencken to pull the pin on the turf. Dr Sykes recalls him saying no. For one weekend tens of thousands of families picnicked on a gritty strip transformed into a green oasis. “The garden party to end all garden parties,” was the headline in The Age. Journalist John Lahey wrote: “the cheerfulness is the one thing that will stick in most people’s minds”. Professor Davison said Professor Yencken had an agenda. “This illustrated how clever he was. This one event was a dramatic way of sowing the seed that Swanston Street could become a pedestrian street.”

Professor Yencken was also responsible for the redevelopment of Southbank. At the time the precinct was made up of derelict factories and the city turned its back on the Yarra River. “A lot of our work in the initial instance focused on the central area of Melbourne because there was such a sense of neglect and lack of policy direction,” Professor Yencken told Planning News in 2017. “This lack of effective action was being expressed in papers like The Age on a very regular basis. We had a big program and that included Southbank.” Professor Yencken’s introduction to architecture and building was a road trip through Canada in his early 20s, where he wrote he was introduced to “several wonders of the new world: hamburgers, three-minute car washes and motels”. He built one of the first motels in Australia in Bairnsdale in 1957 and later asked architect Robin Boyd to design a second - The Black Dolphin - in Merimbula.

In 1965, Professor Yencken co-founded Merchant Builders, which built homes that emphasised the Australian character of the landscape. The firm pioneered cluster housing at Winter Park in Doncaster and Vermont Park, where groups of homes share communal space such as a park or swimming pool. The Winter Park Estate in Doncaster. Credit:Eddie Jim Melbourne University architecture professor Alan Pert says Merchant Builders was ahead of its time. He says its model of suburbia is relevant to Melbourne’s current debates about housing affordability and population growth. “A lot of the things Nightingale is trying to do with apartment building - the attitude of shared space and community - were all things Merchant Builders was doing 40 to 50 years ago in a suburban context.”

Valuing Australia’s National Heritage, which Professor Yencken wanted to see published while he is still alive, is part memoir, part history of the development of Australia’s national heritage consciousness. The book is full of interesting tidbits. Professor Yencken describes his initial battle to persuade a sceptical media that the National Estate was not a middle class conceit. (Curiously, after Malcolm Fraser came to power, he was never asked this question again.) He details the “fierce and unexpected opposition” of Liberal Billy Snedden, then Speaker of the House of Representatives, to Parliament House in Canberra being on the register. But it is also a lament for what Professor Yencken sees as the current neglect of national heritage and the “apparent unwillingness” to add places to the national lists.

Dr James Lesh from the School of Architecture at the University of Sydney says Mr Yencken has been a life-long advocate for the conservation of things and places. “As businessman, as developer, as conservationist, as policymaker, as urban planner, as educator, his overriding ambition has always been to make Australian society a better place.” Valuing Australia’s National Heritage is published by Future Leaders, a not-for-profit initiative. For a free copy email helen@futureleaders.com.au