I am not an interior designer but for me I honestly think there aren't much wiggle room with layouts to maximise your space (since it could be lack of to begin with). Bog standard when a house is fully done to to maximum potential has the pretty much the same layout in houses we saw across London. 1st floor, lounge and dinning (the wall might be knock down to combine the two) and even the hallway wall knocked down for an open plan. Then kitchen at the back and if planning and space allowed a extension where the side part is also extended. Toilet underneath the stairs. 2nd floor the master bedroom and a toilet or a "bedroom" next to the faster at the front of the house or is combined with the master. The back another bedroom (or two depending on how deep the house is) and a shower and toilet. Loft conversion at the top ensuite and one or two bedroom depending on how deep of the house. I'm not originally from the UK (from NZ), but there are some many very narrow houses that makes me claustrophobic just by going inside (I don't medically suffer from it). What I think is, the houses have similar design in the same area. For example your could be looking at one area where historically were build for servants so the houses tends to be narrow and not very deep vs some othersl area where is more generous. To top it off, I visited a house in Leytonstone which was asking for 1.4m the steepless of loft extension (not conversion) stair case was almost a ladder. I found that it will be useful to search for areas where you like the houses first (obviously your basic needs need to come first like school, supermarket transport), but a lot of house just ain't that easy to change as they are so small and narrow