Implications of switching to upsidedown house

I'm currently renovating a mid terrace townhouse & adding a 2 storey extension. Planning has been granted for an extension (kitchen downstairs, bedroom upstairs).

However I'm now thinking of having all the bedrooms downstairs, and the living area upstairs (primarily because this layout would allow for a lovely open living room (leading to kitchen) with plenty of light rather than the existing dark small living room downstairs well disjointed from the kitchen (and probably wouldn't be used very often).

If I change from the plans, the main external difference would be that looking into the back garden, you would see an upstairs external door from the upstairs kitchen.

Bearing in mind that the floor area would be the same as in the plans, would there likely be problems if at some point I decided to sell the house?

Many thanks,
P