There are different types of change orders, some are because of unforeseen existing conditions, others come from the owner's desire to make changes. As long as both parties work together and are reasonable, changes should not be an issue.
When remodeling an existing home, occasionally there may be surprising hidden behind walls. Most of the time the corrective work is minor, and we take care of the problem without even involving our clients. Sometimes, homeowners choose to upgrade finishes. We price the changes reasonably and never take advantage of our client.
Protect Yourself from contractors who are greedy when it comes to profit margins on changes. Ask them in advance about their policy. Some companies use change orders as a profit center. Here is a quote from an actual contractor in Maryland:
“Change orders are as much a part of our business as anything else we do… Mark-up needs to be much higher… Change orders can be a great way to increase profits!”
When I consult with homeowners, I advise them to push back if a contractor tries to hit you with a change order after the fact. Contract law states that it is illegal to complete additional work without a signed change order. That should be enough leverage to use against a contractor who treats you unfairly.
A healthy relationship with your home improvement professional means a little give and take. If you are reasonable, added value is likely to come your way.