Hi, have just been through basically the same process. In my case the land was gifted from father to son so this automatically halves the Stamp Duty amt. The land will be worth less without planning permission so if you are going to transfer it I would do it before planning permission, so as to pay the less amt. of stamp duty on the value of the land. Your land will have to be valued professionally for stamp duty purposes. If you are going to convert your attic into bedrooms, you will need to put this in your plans before submitting for planning permission or else when you go to sell your house you cannot claim the attic as liveable space unless you have planning permission i.e. if it is a 3 bedroomed house with the attic conversion and you put in 2 extra bedrooms in the attic, if you don't have planning permission you can only sell it as a 3 bedroom house and not a 5 bedroomed one. Your architect will sign off each stage of the building and then you apply for the next stage payment, you can also employ an engineer to do the same. They usually charge per stage payment, ie €200 per signed off certificate. Hope this helps.