What do you think the rules for building inside Oldtown are? Like the buildings have to be made of stone, can only be so tall, have to meet fire safety, etc, etc.

I woud not be surprised if they follow a system of rules similar to those described in William Novak’s The People’s Welfare, which provides a very comprehensive survey of municipal regulation in the late 18th/early 19th century (so at the very end of the Early Modern period slash beginning of the Modern period).