I haven't the faintest idea as to what the procedure of connecting the load in a flat is.All I no is that if the load is inductive then the voltage leads the current as per phasors. When you have an inductive load the voltage leads where as in case of capacitive load the current leads.The light bulbs are inductive loads that means the voltage is leading where as the fan is a capacitive load.As per the circuit diagram the voltage loads should be connected in parallel with each other and then the parallel combination is to be connected in series with the fan.