Tight budget - Single story flat roof extension cost

OH1

Hi, I'm buying a 1970's house in Dublin that will need some updating. I want to combine kitchen/dining room. I feel that the space isn't big enough and won't work unless I extend, say a 6ft extension across the back of the house with sliding doors wall to wall. This will have to be done on a very tight budget as I have the rest of the house to update too! Figures per sq metre seem to vary from 1000 to 2000 sq metre. I think I need a 12 sqm extension only. I may want the roof elevated higher than the original kitchen but don't think I need skylights as the house is south/east facing and gets a lot of sun. I'll be painting/decorating. Reasonably priced kitchen, will do. Are wall to wall sliding doors cheaper than building a wall/window/door etc.,? What's a realistic price for this? Appreciate any advise?

DOCARCH

For the size of the extension you are talking about I'd be erring on budgeting E 2000/m.sq. (+) for the extension (ex. your Kitchen).