It really depends on the wear and tear of the bathroom. If its a high traffic area in the home, then it might need to be renovated more often. Similarly, if there are any major problems with the bathroom (like plumbing issues), those will need to be addressed as soon as possible. However, for most people, a good rule of thumb is to renovate your bathroom every 5-7 years. This gives you enough time to really make some significant changes without putting too much strain on your budget.