Attic conversion - planning permission and neighbour's approval?

Hi,
I am considering turning my attic into a bedroom. I live in a semi detached house. Do I need planning permission when I will have the conversion will have one window to the side of the house?
Do I need to obtain my neighbour's approval formally? I read about signing a party wall agreement but that could be for the UK only.
Thank you.

Most attic conversions in Ireland are done without planning permission. This is because the conversions are not officially habitable space. The extra space is beneficial to the homeowners and, should the property be sold, potential buyers will see the value of this non habitable space.

For an attic conversion to be fully compliant as habitable space, you would require a lot more work done - access/egress, fire safety, fully compliant stairs, linked smoke alarms etc

If you are putting in dormers, front facing veluxes or new gable windows then you are straying into planning territory.

A party wall is one shared between two properties, such as a boundary wall between tow non-connected houses or the common wall between semi-detached or terraced houses.

If your side window is within 12.5m of a boundary you will need to use obscured glass.

The safest approach is to seek a Section 5 Declaration (example, each LA will have their own form). Submit details of your proposed works and they will confirm whether planning is required or not. The added advantage of having a declaration where planning is not required is it will shut down any potential future problems that might arise when selling or seeking permission for other works.