Can I install seamless acoustic ceilings in conversions and refurbishment, or does the system only work for new build?

It is very common for seamless acoustic ceilings to be considered when refurbishing existing buildings. Especially in cases where old buildings are to be reused for new purposes, e.g. an old industrial block that is to become an office hotel. So the answer is yes. Seamless acoustic ceilings can be suitably used in new build, conversions and refurbishment.