Loft space bathroom cost

[MyBeloved]

Hi all

I just wondered if anyone had converted upstairs loft space in a chalet bungalow, into a bathroom...and how much it cost, more importantly. I already know it is possible to do, and it has been boarded out in readiness...it is simply the cost I'd like an idea of.

Thank you 😊

This will be really variable depending on where the water supply, electric and waste are so noone will be able to say without some more info.