Choose contractors to work in your house very carefully. Because the projects they work on will be forever associated with them, their behavior and energy, it’s important that you choose people who will leave you with good results and good memories. Those good results and good memories contribute to the overall energy of your home. Good results and good memories equal good feng shui.
I learned this lesson the hard way. The plumber who installed my new kitchen sink was running his own business for the first time, overwhelmed, exhausted and really struggling to get the sink in. He spewed negative energy all over the kitchen with curses and anger. Unfortunately he left his negative energy behind. Because his behavior was so unpleasant and the sink was associated with him, forever after when I looked at the sink I thought of him. I still think of him when I think of that remodeling situation.
The best way to find contractors who will be good feng shui is to ask discerning trusted friends who they use. Avoid using unknown contractors. You could end up with a feng shui nightmare!