Each person or family has its own requirements for space. Questions to be considered:
How many bedrooms do you need?
Do you require a big living space for guests or social activities?
Can all the furniture from your old property fit into the new property? Can you get large sofas, beds and tables upstairs and through doorways? What about pianos?
Check if the utilities areas are big enough for those big foreign appliances such as dryer and washing machine.
Is there enough hanging space in the wardrobes? Check whether the wardrobes are wide enough to hang all of your clothes.