Stamp duty does not apply on the building when you are personally building. It does arise or may already have arisen on the acquisition of the lands on which you are building.
If you do not own the land on which you are building - you should definitely be talking to a solicitor.
I have a solicitor, but I haven't talked to her about this yet. I'm trying to get an idea of the cost of the project at this stage. I wanted to know for my own budget.
The land is my father's. He will be signing it over to me, so I'm guessing the solicitor will talk us through that. I'm fairly certain we don't have to pay and tax on it though.