A former head of English Heritage has warned that the country’s modernist legacy is being betrayed via way of means of a incorrect-headed technique to twentieth-century structure.

Simon Thurley, who stepped down as leader government in May 2015 after a 13-12 months stint, says landmark homes are uniquely susceptible to demolition, in element due to the fact modernist structure has a tendency to be unpopular with the general public and politicians.

The hassle is compounded via way of means of an unimaginative technique via way of means of conservationists. “At the moment, there may be a ‘one-size-fits-all’ philosophy of conservation,” Thurley informed the Observer, “that’s primarily based totally on [keeping] the unique cloth. For twentieth-century homes, the complete indexed-constructing system, the regulation and the whole lot primarily based totally round retaining the cloth, isn’t relevant.

“These homes are approximately thoughts and different matters. For the 20 th century, you have got to have a one-of-a-kind system. People do not like twentieth-century homes. Politicians additionally assume that, as soon as a constructing’s indexed, you can not do whatever approximately it. There’s a massive disincentive a number of the political training to shop them.”

The lack of a number of the maximum progressive homes of the postwar length might create a black hollow in architectural history, he added. “The risk is that the whole lot may be simply bumped off and the subsequent technology may have in reality no concept approximately that fantastic length of high-quality optimism and backbone to apply structure to convert society. We’ve were given the entirety muddled up … Everybody receives livid approximately it, however it is now no longer being dealt with properly. Saving the past due twentieth century is the maximum arguable and tough place of cutting-edge conservation exercise and debate.”

Modernist structure, with its brutalist concrete bureaucracy and experimental designs, has stimulated extremes of emotion. For instance, Sir Denys Lasdun’s concrete National Theatre, at the South Bank in London, has been applauded as an icon of postwar structure and mocked for reminiscent of a nuclear electricity station. When such homes are indexed or obtain public cash for conservation, there may be a typhoon of opposite from folks that see them as “ghastly”, Thurley stated.

The solution, he argues, lies in radical revamps to enhance them for present day use: “You want to justify extra intervention than you may in different kinds of anciental constructing.”

Speaking after handing over the primary of a chain of public lectures at the topic at Gresham College, London, he stated: “Having left English Heritage, I determined that I should courteously say all of the matters I become bursting to mention for 10 years approximately what is incorrect with the system.”

Under the cutting-edge system, adjustments to indexed homes are depending on neighborhood conservation officials and Historic England (previously English Heritage). “If their mind-set is that anciental cloth should be stored in any respect cost, you are now no longer going to get that permission. They’ve were given to undertake a brand new mind-set, that’s to defend the general concept and significance.”

He stated the case of the Commonwealth Institute, the previously derelict Sixties constructing in London, for example of ways indexed modernist structure may be improved: “When that constructing become being bought via way of means of the Commonwealth Institute, the trustees attempted to get an act of parliament to have it delisted … It become all due to the fact the conservationists were some distance too valuable approximately what to do with those homes. In 2007 it become bought to a improvement consortium who knew what they had been doing.”

This month the constructing reopens as the brand new Design Museum. Thurley stated: “Here’s an instance of a completely contentious case, which has come to a a success conclusion. If they make drastic interventions in twentieth-century homes, it offers them new life. I wager you, while human beings move into it, they’ll love it.”

He added: “You have were given to place one-of-a-kind requirements on those twentieth-century homes. You can not deal with them like 18th-century houses. If you’re too valuable with them, you may really save you them from getting new uses. Some human beings say that the Design Museum conversion has finished this superb constructing and must by no means were allowed. If it hadn’t been allowed, we would not nonetheless have the constructing.”

By contrast, Thurley criticised the demolition of the Grade II-indexed Southside Halls of Residence, constructed withinside the Sixties for Imperial College London and favourite for its fusion of “Oxbridge making plans with extraordinary slab blocks of strengthened concrete”. He stated the choice via way of means of English Heritage to help demolition while the constructing might have been repaired for a complete, become fantastic. “This is a hassle confronted via way of means of loads of noticeably graded homes every 12 months – the reality that the restore charges are extra than the eventual fee of a constructing.

“But what approximately a Grade I-indexed medieval church withinside the center of nowhere? It has a restore bill. Even if permission might be granted for its conversion to a house, it might simplest be worth at maximum. So can we say, ‘Well, let’s demolish it’? No, of direction we do not.”