Lady Godiva and the Snowdon Aviary vie for heritage listing

One moment you are a primary school child watching the Snowdon Aviary at London Zoo being created (with much tut-tutting from the nannies in Regent's Park); the next thing you know, this avant-garde Sixties' bird-house is being recommended for listing by English Heritage as a building of historic and architectural importance. Time, like captive birds, appears to fly ever faster in the ever expanding world of heritage.

Today, an exhibition opening at the RIBA Architecture Centre in London presents the public with 57 varieties of post-war buildings which English Heritage is keen to see listed.

The second of three such exhibitions, this one deals with sculptures and memorials, places of entertainment, "planned town centres", New-Town housing, and rural housing. Has the Sussex town of Crawley's time come round at last? Er, no. But, if you live either at 3 to 12 Orchard Croft or at 161 to 165 Mardyke Road, Harlow, in Essex, you may soon be living in a house listed as Grade II just like the Georgian rectories in the more salubrious parts of southern England.

Both of these rows of New- Town houses, dating from the early Fifties, were designed by Frederick Gibberd, better known as architect of the cathedral of Christ the King in Liverpool (aka "Paddy's Wigwam"), and of Heathrow airport when it expanded into much of its present form in the late Fifties and early Sixties.

Heritage, however, is for animals too. Doubtless there will be many an exotic bird preening itself at London Zoo if the famous Snowdon Aviary (Snowdon, Price and Newby, 1962-65) is listed Grade II as English Heritage would like. The same accolade should flatter the residents of the nearby Elephant and Rhino House (Casson & Conder, 1962-65).

The recommendations for sculptures and memorials include the Kennedy Memorial at Runnymede in Surrey (Geoffrey Jellicoe, 1964-65) and William Reid Dick's statue of Lady Godiva at Broadgate, Coventry (1949). There are five Barbara Hepworths and four Henry Moores on a list that casts its shadow from Devon to Greater Manchester.

Dr Martin Cherry, head of listing for English Heritage, said: "The first post-war listings exhibition in March attracted enormous attention and the public response has been extremely positive.

"By including public sculpture among our recommendations, we hope to draw these works - some of the best sculpture ever produced by British artists - to national attention. Listing will ensure their safekeeping and, in effect, establish the core of a national collection of modern outdoor sculpture."

The apparently eclectic range on show at RIBA's Architecture Centre is part of a comprehensive survey by English Heritage of post-war British buildings. Dr Cherry and his team are keen to see that examples of the enormous variety of building types, sculptures and memorials that mushroomed in the Fifties and Sixties are saved for posterity.

Listing, however, as English Heritage points out, does not necessarily mean that a building cannot be altered, adapted or even demolished; rather "it ensures that its architectural and historic importance is properly assessed before decisions are taken affecting its future".

There are approximately half a million listed buildings in Britain, representing 2 per cent of the total stock. Of these 184 have been built since 1945. We can expect that number to expand inexorably, because the bulk of the nation's stock dates from after the blitz and somewhere in all that brick and cement are aviaries, elephant houses and New-Town terraces which deserve equal footing with the best that the 18th and 19th centuries have handed down to us.