I have my 4 year old on top... we brought the bunks just before Christmas so she was 3 years 8 months. I thought I got the low ones (off ebay) but they werent that low! They have railings all around the top and we havent had any acidents from the top- just a few mid ladder ones at the start where they (Miss 4 and Miss 2) would fight. It doesnt happen anymore! So Yeah... I have Olivia up top, Rebecca on the bottom (she is 2) and Amy in the cot all in the same room. I was thining if we do have #4 we would get another set of bunks and put DD2 up top... by then she would be around 3 and a half- 4!

I think the double would be fine to start off with. Do you really need to move house? We only have 2 bedrooms and an office. It is tight but for the moment its fine and I can see it being fine for at least another 5 years or so! (hopefully) Personally I dont think that its essential for kids to have their own rooms at this age. I tell you what though... I love hearing them at night having chats and when they wake up they have chats too. Its really nice.