I think the design of the exterior has real 70s integrity. A bit of paint is all you need. Replace the garage doors with floor to ceiling windows matching the aesthetic the current windows already have. You should check out Cocontest.com for architecture work, or you could try and find an interior architect (there are degree courses in interior architecture these days) I've seen loads of one plan's posts and it would definitely be worth having a chat with them. I also think that you'll get more out of the project if you can educate yourself a little on design. I do my best to do this over on www.houseplanshelper.com

I agree with Najeebah re pics. Sometimes some styles of house may not always suit certain colours, I know mine doesn't!

Gosh, I've returned after a week travelling for work to loads more suggestions - thanks all! To respond specifically: - the house faces south so gets the lovely morning (and in the uk, sometimes the only) sun. - the husband has avoided putting plants in the planters due to maintenance and they're generally twee so comments here have confirmed to me that they will be coming out - love the idea of wooden boxes with the spiky plants and grasses - also like the concept of taking out the grass/bed/tree in front completely out and replacing with slabs - yes to lightening the windows - to the Barn company, I honestly don't mind the advice and I'd never seen sloping garage roofs. - nicking ideas from landscaping of new builds....great idea! - finally, Helen Scholes, I'm embarrassed about the spelling of kerb. Had no idea! Thanks again all.

Kitchen is actually not a bad size, considering that you have the dining room and that it is the size of some modern kitchen diners. I think some of your cabinets are retro in a good way, maybe not the three quarter height one but the uppers and sliders under the sink are interesting. Could you see them in 50s retro mint green with olive walls or say duck egg blue units and walls and hints of pink or red here and there in the kitchen? You could have them resurfaced by an auto paint company in any colour you like. At the very least don't rip them out and skip them, somebody will love them, they are very in in certain circles.