Rover suddenly claiming all the chairs in the house as his? While couches and your bed might be acceptable furniture for doggie use, chairs can be tricky. First of all, they provide access to tables and counters, where yummy but harmful things await. Rover might also be keen to explore, climb and jump on furniture when you're out at work and can't come to the rescue if he damages something or hurts himself. The sooner you reclaim your chairs, the better.
Remove the temptation. Chances are Rover is getting on the chair to reach something. Maybe table scraps? Or that little toy or the pack of tissue paper you keep on your desk. Hide everything that might be just too irresistible, especially when you're not home to keep an eye on Rover.
Push chairs right under the table or desk, if they fit. Not possible? Move them away from tables before you leave the house. Since Doggie is probably using the chairs to get to something, just moving them away from any surface holding anything "interesting" might be enough to make them seem less attractive.
Put something on the chairs. Anything from a laundry basket to a big backpack would do. If the chairs suddenly become "occupied," Doggie will soon lose interest in trying to climb on them.
Cover the seats with foil paper. Unless you have one of those dogs who will eat everything in sight, foil paper can prove a nice trick. Rover will hate the feel of the foil on his toes and avoid the chair as a result.
Say "no" and mean it when you see Rover climbing on a chair. While it might be a good idea to cover or move the chairs while you're out, make them freely available while you're around. That way you can correct Doggie when he insists on getting up on a chair again. Even better, get Doggie his own chair and then insist he get on that one instead of using yours.