I would recommend white painted walls. Add accessories that are colorful if you wish. You can change it anytime you want. Depending on the space, I would definitely add something like raw thick tree branch. You can then make some fairy doors on it in color. Interaction with a child making these doors :) I would also choose funky prints of animals over the decals. Or have some animal heads hung on the walls. Children loves cozy spaces canopy is the thin. I would recommend Numero 74. I love their range of colors and quality. Add some cool pillows. If you are into diy, make some. Paint on it, embroider, use different techniques to apply color and texture to the room. Have more than one lighting source: fairylights, floor lamp, etc. If you want something really cool: cover ceiling in polka dots. Don't paint it. You can cut out some cardpaper circles and stick it with blutack. Use different sizes one color rather than having different colors. Take it off when tired of it easily. Enjoy decorating the room :) V

I think if the location works for you and you can afford to extend, and can’t find a better alternative then it make sense to extend. Especially if you’re going to stay for a while! We are nearing the end of quite a big extension/refurb and it has cost a lot, but is cheaper than moving would have been, and we are aiming to stay here for the foreseeable future, so it felt worthwhile spending the money. If you’re extending, moving walls, new bathrooms and kitchens, it will rapidly add up, as you’ll also need new Flooring, extra windows etc Is there enough head height in the loft to do a partial loft conversion perhaps?

If you intend staying here for a decade then you should make this house work for you and not the next people. I think that since you have already flagged extending in 10 years you should also future proof your plans now. If it were me I would have a bedroom where the current big bathroom is in order to give you the possibility of later extending over the ground floor extension. I would also want a super sized bathroom for my use - I have always believe the person paying the mortgage should have a better bathroom than people who visit three times a year. And I would take the view that when a loft bedroom is later added it won’t matter if one of the four bedrooms is compact. So I offer an alternative.

I also don’t think you can live there while it’s being done. I think you should look into raising the roof then connecting the main house roof to the roof of the kitchen wing. I also don’t think you need to remove what looks like a top end conservatory. But you do need to find a good architect to help discuss what is possible and you need to think about your budget as it’s a big undertaking. For what it’s worth this is what I would do.