You know you’re getting old when the buildings you grew up with start getting listed by English Heritage. There’s a 30-year rule in preserving historic buildings, designed to give some critical distance, so by the end of this year the whole decade of my childhood - the 70s - will be up for grabs.

Already the battle has begun. Last week the government turned down for listing Richard Rogers’ Lloyd’s Building in the City of London, designed in 1978. Admittedly, they didn’t start building it till 1981, so the government was well within its rights. Nicknamed the ‘Espresso Machine’ for its shiny pipes and industrial aesthetic, it became renowned as a symbol of the decade’s red-braced, Beaujolais-quaffing yuppies. But the 30-year-rule doesn’t stop them emergency listing buildings that are either already lauded or under grave threat - they did it 18 years ago with one of Norman Foster’s great early works, the former Willis Faber Dumas building (1975) in the centre of Ipswich, the only British building from the time Lloyd’s equal. And for some, Lloyd’s ticks both boxes. That it’s the most significant British building of its era is beyondedoubt. Even English Heritage, which recommended not listing it quite yet to Architecture Minister Barbara Follett, said it had “outstanding architectural merit”, and told The Architect’s Journal it had “no doubts” it would be listed when it automatically comes up in 2011. So, er, what difference does two years make? A lot for the Twentieth Century Society, who put it up for listing at the highest level, Grade I. They fear its architecture is already being whittled away through a series of changes by its German owners to update it for the City’s now slumped commercial property market.

The Society is usually ahead of the curve when it comes to valuing the recent past. It’s their job. They banged the drum for 1930s architecture in the late 1970s when it was thought expendable. They championed 1950s architecture like the Royal Festival Hall. And by the late 1990s, they were lauding the 1960s, its threatened, often Brutalist architecture like the National Theatre and the Barbican Centre out of place in New Labour’s shiny bright millennial future.

But the front line has definitely moved on to the 1970s. Some people, I bet, would rather consign the whole decade to the dustbin. The flares, the economic gloom, the Findus Crispy Pancakes: Channel 4’s Red Riding trilogy brought it all back to me like Proust’s Madeleine. And in architecture, too, some might see it as the lost decade - a hiatus between the fag end of postwar modernism and the Day-Glo joviality of 1980s postmodernism. The Twentieth Century Society, though, is bucking the trend, starting a campaign to raise awareness of the decade’s architecture (www.c20society.org.uk/docs/campaigns/70s.html), and good for them. My childhood needs saving!

Its pick of the 1970s shows up the magnificently eclectic decade perfectly. The big story was cosy modernism. Understandably slagged off by conservationists bitter at the mass redevelopments of the 1960s (and those who had to live in the weaker examples), postwar modernism made its apologies, dusted itself down and came back in new clothes: still sharply modern, but getting all domestic like Aldington and Craig’s housing in Buckinghamshire. Its cottagey looks, pitched roofs and brick walls set the trend for the domestic landscape of Abigail’s Party and the Good Life. Even council housing ditched the ‘inhumane’ scale and got, well, cosy-ish. Some buildings like MEA House in Newcastle continued to look like giant mainframe computers. But after the devastating gas explosion at Ronan Point, east London, in 1968, the cheaply built tower blocks that dominated the previous decade were out. Better quality, low rise-high density was the thing - even the good old-fashioned British terrace, demolished in slum clearance not 20 years before, came back into fashion. Camden Council in north London became, architecturally at least, the most progressive in Britain, with a late flowering of mass housing reinventing the terrace in modernist dress like Gordon Benson and Alan Forsyth’s Mansfield Road housing.

On the other hand, modern architecture got the space-age bug: the hi-tech style of Norman Foster and Richard Rogers, with its spidery steel and machine-look showed we hadn’t quite lost all our faith in the previous decade’s white heat of technology, even though the nostalgia of Laura Ashley country smocks, toasters with wheat sheaves on and BBC period dramas were beginning to define the country after the oil crisis. Norman Foster’s IBM HQ outside Portsmouth come from a time when open plan offices and brown tinted glass were still cool; a little, cheerful fragment of West Coast America in gloomy old 1970s Britain, not the architectural version of medallion man. There was even a kind of disco modernism, like Arne Jacobsen’s groovy Danish Embassy in Knightsbridge: brown has never been so sexy.

Tell us what would you save from the decade that style supposedly forgot, and what should never insult our eyes again?

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010