Nickle, I have two of each gender so they share a room - we only have a 3brm house but it works out fine. Yes you will need a new car though, but there are so many awesome ones that don't seem like a big box on wheels. I've been trying to think of a negative and in all honesty there aren't many. The only thing that would be hard are the medical/dental costs we've had for the kids - we'd be screwed if we didn't have PHI covering most of it. So that is something to consider I suppose - you might be able to *afford* 4 kids, but can you afford it if you end up having 2 or more in braces (like we will be - their teeth are terrible) or glasses etc? It's not so much that we can't afford it, but it certainly makes it a bit harder at times kwim?