I am 99% certain the owner will not accept your offer with a contingency, you would have to show a contract on the sale of your house. If they do consider it, they would insist on keeping it on the market until you have a deal on your house. If you can carry both houses for a few months, however, and can waive the contingency, then go ahead. In other words, put yourself in the owner's shoes (as you would be the seller for your own house) -- would you accept an offer contingent on the sale of someone else's property? How could you move ahead with your plans with this uncertainty? Talk to your realtor about other options -- if you need me to refer you to someone, let me know!