Refinish one room per year. With a 4-BR house, that's about 9-10 rooms, all told (generally). At that rate, every decade, each room will get updated once. Don't try to tackle them all at once, you'll get burned out. I've refinished 4 rooms and both the upstairs and downstairs hallways here in the last 18 months. I don't recommend following in my footsteps.