Thanks nymom. Good advice. Husband is a bit reluctant to take up the new lovely wool carpet (oatmeal colour was never the best plan anyway with kids! - but there is no comparison between the dust I got upstairs from carpets vs wood floors downstairs (x 30 times more I would say, also shows how crappy our 6 month old hoover was, as I had hoovered twice last week with it!). And yes, got rid of all but four soft toys (those 4 are currently in the freezer!). Floorboards it is, if you have found any flooring on top of that particularly good please let me know. Sheets of flat rubber may be a solution, no joins and no raised areas, will have to look into it... If anyone has any info on experts for ventilation that would be amazing, in winter the windows in his room (double glazed) always have condensation, shows what a great breeding ground that room has been... Eugh.. (I give up!)