Quality Window Installation
Who is going to install your windows? I hope you don't plan to do it. If they are replacement windows, you can have a difficult time if you are not experienced. The final fit and finish of the windows and their performance is directly related to expert installation.
All too often rookies or weekend warriors forget important steps regarding air infiltration or insulation. Caulking is also very important. Sometimes an inexperienced installer can install too much insulation, use the wrong spray-foam insulation or make a horrible mess with a caulk gun.
So who should you have do it? I vote that the window company installs them. Not only that, I want an actual employee of the window company and NOT a sub-contractor.
You need to ask about this because the use of sub-contractors can be appealing to a window company. Using sub-contractors can save a window company money because they have cost control. They pay the sub a fixed sum to install the job. This is good for the window company but bad for you. Why? What happens if your job is exceptionally difficult? The sub may cut corners so he makes more money or doesn't lose money.
Insurance issues are cloudy with sub-contractors. What happens if the sub gets hurt on your job? I know of one job where a sub-contractor severely cut his hand while removing an old window. Fortunately, the sub-contractor had Worker's Compensation coverage. The sub on your job may not have this coverage. Who pays for his medical bills and lost work wages? You do!
Employees of window companies know their product very well. They know the best tools to use, the best insulation, the best caulking and the best techniques. They get paid by the hour so they are under no pressure to "rush" your installation. Be sure that the window company you select proves they have insurance coverage. Ask for copies of the certificates. Get all promises in writing.