Even if you get more than you paid for your house at resale the chances that it is because you have a new gate or a new screen door is doubtful. Hardwood floors yes that is an upgrade. What you put into a playroom be it carpet or hardwood is done for the sake of the children. Now having said that the actual creation of a playroom ie finishing the basement is an area where it does increase the value of the home at resale so the cost could be clawed back. The option is to only claim the finishing details as in the basic structure is a home renovation for improvement but paint, finishing, is for the sake of the children.