We will only have 2 years gap, but in a 2 bed apartment - but my intention is that number 2 will be in with us until feel his waking over night is suitable for him to go in with my DD. If he is like her that will be at 3 months (as I think if waking once a night will be ok with DD as based on how she reacts to noise now this won't bother her) but he may be in with us for much longer. My mum will be staying with us for a while 8 weeks after this one is born anyway and she will be in with DD so DS has to be in with us (if my dad visits for a few weeks too, is going to be very cosy :-))