There is a system of heritage listing for buildings over a certain age and in some styles. Anyone owning one of those and wants to make changes has to get specific approvals. Mostly they are not allowed to change the outside look (and some internal features - e.g., painted ceilings). Often we see in the city a new building built behind and above the facade of the old building. Looks the same outside but a little taller and is all new inside. Where I was walking is one of the older suburbs - lots of buildings from the late 1800s and early 1900s.