The director of the UK's Twentieth Century Society has urged prime minister David Cameron to ditch plans to demolish post-war housing estates or risk an architectural "tragedy".

Catherine Croft warned that demonising post-war estates would not solve the housing crisis, after the prime minister pledged to demolish or "regenerate" 100 of the social housing developments across the country.

She said Cameron was using emotive language to create a "knee-jerk" response that could leave residents worse off.

"It is still all too easy to condemn estates by describing them as 'high-rise' or 'Brutalist' (or worse, in today's BBC article, as simply 'brutal') and get a knee-jerk reaction that blames poor design for major social problems," said Croft in a statement issued today.

"It would be a tragedy if any more decent, well thought out and essentially humane estates – and yes, that can include both high-rise and Brutalist ones – were to be demolished and replaced with schemes which will almost certainly increase the density of site development, meaning smaller room sizes and less amenity space, yet with higher rents."

Cameron unveiled plans to spend £140 million on jumpstarting the redevelopment of 100 estates in an article published in last week's Sunday Times and on the government's website.

He described post-war social housing estates as "brutal" and a "gift to criminals and drug dealers".

Under Cameron's proposals, some existing social housing buildings and public spaces could be replaced by private housing developments, using high land values as an incentive for further investment.

Using the space currently occupied by council housing as an asset to encourage private investment risked replicating patterns that have already seen local people forced out of their areas, said Croft. She pointed to the controversial demolition of south London's Heygate Estate as one example.

"The danger with the funding identified by Cameron is that this will further encourage the demolition of estates sited where land values are high enough to attract private investors," said Croft.

"For both financial and environmental reasons we should only be demolishing estates which are genuinely irredeemably flawed. Many more problems are caused by poor maintenance and housing management, and can be turned around much more economically without disrupting communities."

The Twentieth Century Society is one of the UK's leading heritage organisations, and campaigns for the protection of 20th-century and contemporary architecture. Croft, formerly a journalist, has been director of the organisation since 2002.

Cameron's announcement came days after the government passed a controversial housing and planning bill that some believe will reduce the number of social housing units built across the UK. There are currently an estimated 1.4 million to 1.9 million families or individuals on the waiting list for social housing in the UK.

Dezeen columnist and architecture critic Owen Hatherley described the prime minister's announcement as "infuriating" and "idiotic". But architect Glenn Howells welcome the plans, saying that regeneration of estates could have a wider benefit to towns and cities if delivered in a "really integrated way".

Read the full statement from Catherine Croft:

Each morning I stand at Elephant and Castle train station and look out at the site of the Heygate Estate, now being redeveloped with depressing towers, and with little prospect of the new scheme providing homes for local people. I am also very concerned about many of the Ted Hollamby schemes across Lambeth, excellent examples of low-rise high-density which are currently very much under threat of demolition. I am sure I am not alone in having this critical issue face me in the neighbourhood where I live – it is a very wide-spread issue.

The danger with the funding identified by Cameron is that this will further encourage the demolition of estates sited where land values are high enough to attract private investors. For both financial and environmental reasons we should only be demolishing estates which are genuinely irredeemably flawed. Many more problems are caused by poor maintenance and housing management, and can be turned around much more economically without disrupting communities. It is still all too easy to condemn estates by describing them as 'high-rise' or 'Brutalist' (or worse, in today's BBC article, as simply 'brutal') and get a knee-jerk reaction that blames poor design for major social problems.

It would be a tragedy if any more decent, well thought out and essentially humane estates – and yes, that can include both high-rise and Brutalist ones – were to be demolished and replaced with schemes which will almost certainly increase the density of site development, meaning smaller room sizes and less amenity space, yet with higher rents. There are a few examples of bad estates where poor construction must be tackled by drastic action, but these are the exception. Demonising housing estates is not the solution to our housing crisis.