The build

It’s open pitch in the living room
Hate velux windows very noise when it rains (which is often) and an ar$e to clean. We have one here. 
We’re having underfloor heating and a MVHR mechanical ventilation and heat recovery unit .
Our architect was kept on a very short leash    . He soon learned that I don’t mince my words and NO meant NO !

What will power the underfloor heating system?

Are you recycling the exhaust fumes from the cooker extractor as part of your MVHR as well?

You can always coat glass so it doesn't need cleaning under a microscope glass looks like orange peel. Plus it's really difficult to put curtains or blinds in front of pointy windows. Personally I've always liked the sound of the rain on a velux, well any glass really, it's a satisfying feeling knowing I'm on the inside not the outside at that very moment.    

Remember if you don't show me your plans, I can't change them