So I have 3 thr projects available but Isabelle said I can't demolish them once they're done. Does that mean I can only choose one permanent town hall design and not change ever?
you cant "demolish" it but you can start a new town project to over write it. It just means you cant go back to the original the cheap way you have to rebuild all over again.
Wow! I didn't think you could. I thought it was undemolishable, but at least that gives some room to re-renovate in the future. Although it /is/ a very expensive project.
You can not demolish it but you can turn it back to normal in the town project selection it cost the same much so choose carefully too not waist money!