Along with lofts, rear extensions and garages; conservatories are one of the most searched for planning queries in the UK.
In short, yes you will need to declare to the council that you are building a conservatory. However, as we've discussed previously the type of application you decide to go with, will be determined by the size of the conservatory.
A conservatory is classed as an extension, so it falls within the same planning framework as any other type of addition to a property. To find out which type of application you will require, please read our planning article here.