Sydney’s NIMBYs - the anti-development, not-in-my-backyard campaigners – might have to accept denser housing if they want better public transport and services, says the McKell Institute.

The institute has released a postscript to its Homes For All report, which was released a year ago and included recommendations to fix what it called Sydney's housing affordability crisis.

The report finds that aspiring homewowners are being priced out of the Sydney market and that fewer homes are being built, leaving a high number of people on the state's public housing waiting list.

The McKell Institute’s executive director Peter Bentley said the assumptions about NIMBY campaigns needed to shift fast.

“For too long we have framed NIMBYs as plucky Davids fighting terrible developer Goliaths,” Mr Bentley said.

“This is historically understandable. The modern anti-development campaigners grew out of the 1970s ‘green bans’ in which construction unions supported local communities by refusing to work on developments that were deemed to have a negative impact,” he said.

“Today, however, far too many of these NIMBY campaigns are reflexively viewed as principled, when, in reality, they are typically just powerful minorities trying to protect their own real estate to the detriment of the majority.”

“The irony is, that far from improving their neighbourhoods, they are actually eroding Sydney.”

Mr Bentley believes that for Sydney to have major transport infrastructure developments and economic growth, the city needed to start building affordable, high-density housing.

“We simply can’t go on pretending that NIMBYs can defend their patches without massive negative ramifications for the city as a whole,” he concluded.