Required permissions for converting a bathroom to a bedroom

Hi, thanks for providing this resource! I have what's hopefully a simple question, but I haven't found anything directly similar in searching, and my lack of experience is making me think twice.

I own a 2-bed maisonette, share of freehold with the owner of the ground floor flat. There is a large bathroom with a bath and a shower on the 1st floor, and a bathroom with just a shower on the 2nd floor. Next to the bathroom on the 1st floor is a large cupboard with a washing machine.

I'd like to convert the bathroom on the first floor into a bedroom, moving the toilet into the washing machine cupboard and installing a small sink alongside. The washing machine would be moved to the kitchen. I would install a bath/shower in the 2nd floor bathroom, which would most likely require moving the toilet and removing the existing shower.

The flat is in Barnet, in London. I spoke to someone from the council today who was particularly unhelpful as to what permissions I need for this work, or if I need any at all. Looking at the council site, I think that I may need to submit a Building Notice (https://www.barnet.gov.uk/citizen-h...ontrol/forms/Building-notice-application.html), but I'm not sure whether the planned work is relevant for that.

Can anyone advise? I appreciate any thoughts!

Building regulations covers sanitary fixtures and fittings and certain electrical changes so, technically, you need to make an application. There are two ways to do that - a building notice being the simplest.

Means of escape will be important to the building regs person.

You will/might also need the landlord's permission depending on your lease terms.

That's brilliant, thank you for the information! I'll go ahead and apply for the building notice. Cheers!