If you are from the UK the answer to this question is all extensions need planning permission the only exception to this rule is if it is a porch which can be built without planning permission* if its ground area does not exceed 3 square meters, its eight from ground level does not exceed 3 … Read more

Often it can be desirable to use one wall as a feature wall or two if you do it all purple it may be a little restrictive I suggest you pick an opposing wall to a window so that light from this will not make it seem to dark