Hi, we're doing a side return extension on a Victorian mid-terrace, ground floor flat, converting it from a 1-bed, 1-bath to a 2-bed, 2-bath with a habitable (or utility+study) basement room by excavating a bit from current 1.6m ceiling height. The original stairs down to the basement was removed at some point, and the previous owner moved access to be from the outside garden.

After back and forth, it seems our starting decision comes down to where the stairs to the basement hours, and every other decision stem from there! Should we (A) put the stairs in the existing spot next to a light well, or (B) rebuild the stairs in the original location. Both options in the layouts leave the same area for the open plan living-kitchen-dining but obviously affect the flow!

What would you do? Or might you do something different?

Layout A (left) has the stairs next to the light well - I only drew the section that's different to B. It would mean the sitting area has to be designed as a pass-through space. This option allows more light to the interior spare bedroom though.

Layout B (middle) has the stairs on the left, attached back underneath those going up to the flat above. The resulting entrance to living area and basement make them easier to design for. Less light for spare bedroom.

Basement footprint (right) stays the same, showing where options A and B enter. Layout B gives the basement a larger patio although half covered.

I think I might leave optimising the living room's open plan layout for another question/discussion...? 😅