Hi there, it will be hard to achieve an open floor plan with this side extension . In fact, it seems it would just complicate things in a very expensive way. If you don't need a 4th bedroom every day, but just occasionally for in-laws, can you make the garage into a small, compact guesthouse? If your kitchen feels too small, you might just want to relocate it to the room with the fireplace. I hope this helps, please let me know if you have any further questions, I will be more than happy to help. just drop me a line to service@betterspace.co

Hi, Take a look at https://www.homebuilding.co.uk/extension-cost-calculator/

Our side return extension is similar. We went with a pitch roof and velux windows - this is partly because it was about 10 years ago and we didn’t think about these things, and partly because we’re in a conservation area and the planners wanted the roofline to look as traditional as possible. The positives about the velux windows is that they are relatively easy to clean (although we left a small path along the side - so that helps!). There’s no getting away from the fact that the room is quite dark - we always seem to have to have lights on, and now I wish we had much bigger windows. My brother has literally just finished his side return and gone for the flat roof and flat roof lights. It looks amazing - but like yours, he has no path and cleaning them is going to be a real pain. Regarding the neighbours - the velux windows nearest the main part of the house are overlooked - but really not very much - when sitting underneath you need to strain your neck to see the neighbours back bedroom. It really isn’t a problem, and unless your neighbours spend their time in their back bedroom spying down on you, I can’t see it being an issue at all!!

I think you have to say whereabouts in the country you are. In London, it’s going to cost you about 180K. And if you have the manhole cover on your side rather than your neighbours, it can be more tricky.