Converting a garage door to a window semi d in dublin

While it doesnt specifically state in the Regs (see Class 1 of the exemptions here) that a garage door can be replaced with a widow it is accepted that a domestic garage conversion includes a window to replace the door. You just need make sure that the garage conversion is for domestic use and does not breach a condition attached to planning permission for the parent house or the house isnt a protected structure.

You will need planning if changing the facade to a building

There isn't much more advice that can be given. Based on the information provided planning permission would not be required. However if you want to be absolutely sure you can make a Section 5 application to your local council. It takes about 5 weeks to get a written response and that will confirm the planning status of your proposal.

No you don't