Thanks Adrian Had a look at your gallery - impressive !

While I’m sure it’s a travesty to paint mahogany, and my son couldn’t believe I had our oak furniture painted, I really think they look very heavy with the rest of the room. I think you should definitely paint them white. Alternatively you could sell them to Save them being painted and replace them, if you wanted to, with something much lighter and possibly sliding. They wouldn’t be in the way at all then.

Flat rooms always leak in the end so I'd say change it for a pitched room, maybe a metal roof with a shallow pitch rather then a full tile roof? claddig down the right side could look good, wither in wood or a metal. the main issue for me is the rather opressive nature to the extention and the front door. it doesn't look very welcoming at all, maybe you could add a porch or render it in a different colour to the rest? make it a grander statement around the door and change the garage door for somthing with some small windows in at the top? I do 3d Digital modeling for exteriors so if you want help I can create a digital model remotely so you can see what it would look like and play with options before you do anything. https://www.youtube.com/watch?v=vkw45EnYYfk https://www.youtube.com/watch?v=F4ALhPgqHSY Let me know if you need any help.

I think the relative 'darknes's of a house determines the perceived temperature of the paint used. I've used Slaked Lime before in a really light house but it doesn't quite work in a darker house, Portland Stone has a little more warmth and colour ot it. Neutrals are way harder than saturated colours!