Two property developers, Ali and Amanda Hassan, have spent 20 months and an estimated $700,000 trying to demolish an unremarkable brick bungalow in the Sydney suburb of Coogee and replace it with a modern duplex.

Even though five independent consultants, and the council’s own staff, determined the house at 3 Berwick Street is unexceptional, Randwick City Council has given it a heritage designation, which means it cannot be knocked down or changed in any substantial way.