Peckham Library, SE15, could become the first building from the 21st century to be granted listed status.
Heritage group the Twentieth Century Society is pushing for the Will Alsop-designed building, which was opened in 2000, to be given Grade II* status. It wants to prevent the addition of an air-sourced heat pump in the roof, which it fears will ruin the aspect of the library and reduce its significance.
Catherine Croft, director of the society, said the addition would be “like a row of portaloos at a festival”.
The avant garde design, with its jaunty columns propping up hanging spaces, won the Stirling Prize for architecture.
Last month, Alsop’s Le Frégate Cafe in Jersey (1997) was awarded Grade II listing – making it the youngest listed building in the British Isles and the first Alsop project to be added to the national register.