Relax heritage building code: SA Libs

South Australia's opposition wants to relax restrictions on heritage buildings to breathe new life into Adelaide's CBD.

The Liberals will propose legislation allowing the state government to override commonwealth building code restrictions on adapting and reusing buildings constructed before 1980.

"Rather than just sitting empty, dilapidated and underutilised, we want to see these buildings come alive again - whether that be for hospitality, residential or office purposes," opposition leader Steven Marshall said on Thursday.