Brutalism's image makeover is reaching its zenith, surely, with the National Trust – that bastion of period properties – jumping on the brutal bandwagon. The institution is hosting 'Brutal Utopias: a National Trust celebration of brutalist architecture', with exciting behind-the-scenes tours of some of the most important brutalist structures in London, Norwich and Sheffield.

Championed by young pioneering architects determined to reinvent social housing after the Second World War, brutalist homes replaced bomb-damaged slums. But despite the optimism, they were too often poorly maintained. What had been crisp concrete sometimes ended up as a sink-estate.

Sheffield's 1961 Park Hill housing estate, which is on the National Trust's itinerary, was an example of all that was wrong with the movement. Its architects Jack Lynn and Ivor Smith were heavily influenced by Le Corbusier's Unité d'Habitation in Marseille, hence the al fresco corridors or 'streets in the sky'. However, Park Hill suffered from social issues and neglect, and was only saved from the wrecking ball by being Grade II* listed in 1998. Studio Egret West and Hawkins\Brown are now renovating it for developers Urban Splash. 

On tours of the Southbank's Queen Elizabeth Hall, Purcell Room and Hayward Gallery in London, visitors will get to admire the original fixtures and fittings that are normally off-limits, before the buildings close for a two-year, £24m refurbishment by Feilden Clegg Bradley Studios.

In Norwich, tours will be conducted around the University of East Anglia, whose campus was designed by Denys Lasdun, architect of the National Theatre. Perhaps visitors will catch a glimpse of the £8m redevelopment of Norwich's Westlegate Tower, which is being transformed from a defunct 1950s eyesore into luxury apartments by 5th Studio.

As well as the on-site access, the National Trust is arranging a romp around London aboard a 1962 Routemaster Coach. Tours will take in concrete delights including Frederick Gibberd's Lansbury Estate; Chamberlin, Powell and Bon's Barbican Estate; the Alexandra Road Estate by Neave Brown; and Ernö Goldfinger's Trellick Tower. A must for fans of brutalism's concrete charms.