What heritage experts and architects consider to be of social, historical and design importance is often met with scoffs of laughter by a public who think they've collectively drunk the Kool-Aid, which makes getting the green light for protecting some of the state's jewels increasingly hard.

And considering that the next wave of buildings to be considered for preservation are examples of brutalist, featureless, modern and post-war architecture, experts are worried we are leaving a generation of buildings that showcase the city's architectural evolution vulnerable to developers.

Felicity Lewis, from the National Trust, says there's "no doubt" we've already lost some significant examples of this era, in part because of public opposition.

"We've got the situation now where what people traditionally think of as heritage is Edwardian and Victorian-era buildings," she says. "Those styles are quite well represented on heritage overlays, so what the National Trust is trying to do now is to focus on the future of heritage; these are the buildings that are significant but might be seen as challenging."

These are the featureless buildings that get regularly labelled "ugly", "plain" or even a "monstrosity". Examples include BHP House, Victorian State Offices, 15 Collins Street, National Mutual Plaza, Naval and Military Club and IOOF Building.

The Surrey Hills telecommunications tower at the centre of a heritage row. Photo: Joe Armao

The most recent battle occurred earlier this year, when the collective blood pressure of the City of Whitehorse's residents went north when the Victorian Planning Panels recommended protection for Surrey Hills "eyesore" – the Telstra communications tower on Canterbury Road – and The Burvale Hotel in Vermont South.

Experts stated the 45-metre steel structure that had cast a metaphorical shadow upon its neighbours for years was "a striking element in the suburban landscape", which was once the highest point in metropolitan Melbourne.

Likewise, the hotel was billed in a Heritage Alliance report as "possibly the best and most well-preserved example" of work from the firm of Jorgensen and Hough, a leading designer of post-war hotels and motels.

But thanks to a deluge of public protests, which included calling the tower an "appalling monstrosity" heritage action was dropped.

Ms Lewis says the delicate balance between public opinion and expert's recommendations is tricky, and will only get harder, unless more people begin to see beauty in a different way.

"[Public feedback] is not based on evidence, it's just opinion. But the challenge in all of this is balancing the necessity to push boundaries in heritage and embrace emerging heritage and also to respond to those community expectations as well. Because that's an important part of the process."

It's not just brutalist architecture that the public finds hard to swallow. Other post-war styles, including curtain wall and expressed structure, which have in common spareness in design and use of utilitarian materials, also lack widespread devotion.

Judging what is valuable based on looks is a subjective business. Pauline Hitchins, spokeswoman for Heritage Council of Victoria, says what one person may value as significant, others would view as, well, ugly.

"Architectural preferences, like art or fashion for example, is quite subjective and it would be impossible to say," she said. "For some, ornate Victorian buildings are 'ugly' while others dislike moderne​ style, which some might describe as featureless."

What experts are counting on is a gradual shift in public opinion, which would make their jobs much easier. It's happened before; in the 1970s, there was strong opposition to Flinders Street Station, with the public consensus that it should be demolished. Likewise, Federation Square, aka "shard city", was almost universally loathed when it was first unveiled, but opinions have since softened considerably.

Professor Philip Goad is chairman of architecture at The University of Melbourne and is a self-confessed fan of post-war buildings. What's exciting about this era, he says, is that it's when Melbourne as a city and culture was "booming". And he adds it's worth preserving.

"It expressed a new type of confidence, the idea of Australia moving away from the typical John Brack's Collins Street at 5pm – the drab city. And Melbourne architects were experimenting with new ways of expressing the city and some of them are very interesting."