You'll need to ask the Kingdom of Bretonia for rights to build it, tell them where you want to build it, who can dock there, what it will be used for. If you don't ask, a lot of BAF battleships will show up to destroy it.
They'll tell you if it's approved, and how much the fee is per month. There may be some other things, I don't know Bretonias rules.
This thread is where you should request permission to build a base in Bretonia.
However, long as server rules go you don't need a permission to build a base, you can build a base wherever you want. These "permissions" are more of an InRP deal, to make sure the house government does not blow up your base. You can also contact Mollys and work out a deal with them, but I doubt they'd be happy with a base in Dublin.
Also, your post there has to be in roleplay (Means it should be written from the base owner perspective, not you as a player), check the other posts in that thread for some good examples.