hi Jamie For side return extension if that is your plan be ready with about 70k+VAT budget and another 10k in total for client supplied items. that means you still have another 36k£ to spend on your project. as i haven seen your windows on a front i can just guess but i would say with 1 external door and 5 windows assume about 5k+VAT incl installation. bathroom refurb can cost you around 5k+VAT and refurbish of the whole ground floor about 15k+VAT incl new door liners couple of studwalls new plastering new skirtings and architreves etc. for flooring and other stuff allocate about 8k+VAT and for profession fees another 4k+VAT. i would say in total a bit tight but you can have all your list to be done. just be sure you get more quotes in as builders are charging nowadays from a-z depends on there availability and flexibility. have a good luck.

Hi David, see an alternative below- the yellow L shaped kitchen worktop provides good amount of space with sink facing the garden and hob against the perpendicular wall, the grey bit is floor to wall cabinet with fridge freezer. The wonky rectangle is dining table (all red bits are windows) and a downstairs water closet. The garage doors lead up to a small storage area where you can house your wheelie bins and other stuff that require easy access to the outside. Getting rid of the doors while you enter the living room may open up the area a bit more if that’s possible. Clean simple layouts always make a space more flexible in the long term. Hope you achieve the space you are after!

Rinked, I also considered that, but the table and chairs would block access to the back garden. The front extension would significantly block most of the south-facing light in the living area, the back double doors, are north-facing so they don't bring in any light. So while I agree that you need some sort of entrance into the home, The front extension is a mistake in my opinion. In regards to the comment of keeping the passage, yes it's good to have, however, soo many people who live in terrace houses don't have that option and I don't see that as a significant issue.

I'd also be inclined to swap them as Jonathan suggested. Check fire regulations, as perhaps you do need to rotate the stairs to allow an open kitchen. (I'm in the Netherlands so can't advise on these.)