We are extremely lucky that we have a playroom. Rather than using our formal lounge as a lounge room, we turned it into a kids area and plan that in many years to come it will become a teenagers retreat. There are no toys kept in any other area, and although DS will sometimes bring toys to all parts of the house as part of his play, once he has finished playing with them - back they go. We tidy up the toy room at the end of each day and put all the toys away, it means that we don't lose any, and as the toy room is clean, he plays more productively rather than just ignoring a big mound of toys IYKWIM. Although obviously kids take over a massive part of our lives, I think its important to have grown up space and a designated play area. Toys are like a cancer, they multiply at an amazing rate and can take over if not kept in control