Ask to see examples of past work
Most companies should have either reference photos to previous work or a showroom where you can take an in-depth look. Never work with a contractor who won’t show previous work.
Will this window installation take long
This is a key question to ask your window contractor. Most companies bill labor costs based on the amount of time needed for the installation. You need to know how much time you’re looking at and whether or not you can shrink that time depending on weather or crew size. Most contractors won’t be able to give you an exact quote, but the contractors with plenty of experience should be able to give you a reasonable estimate.
Do they have insurance and a license
This may seem like a common-sense assumption, but the fact is many contractors work without licenses or insurance. While that’s not necessarily a testament to their abilities or experience, hiring a contractor without insurance or proper licensing can cause you significant headaches if things go wrong. At the bare minimum, you want your contractor to show proof of liability insurance (to protect your home) and workers compensation insurance (to protect their workers in your home). If you’re working with a historical property, you should also double-check that your contractor has the proper city and state licensing to work on the property.