This is almost identical to a ground and first floor extension we have in planning in Perivale at the moment- going out 3m with the first floor, and 4m with the ground floor
a set of bifolding doors in grey aluminium closed and looking from the outside
Add a few metres to your house for a new kitchen/diner that leads nicely into the garden.
semi detached house extension - Google Search
SJ: interesting how the roof lines goes around the window frame for additional height. Not my preferred style of extension though.