You should only work with contractors who are licensed to work in your state. Window installation can be very difficult and can require specialized equipment. Your contractor should be licensed as a general contractor by the state and should have all necessary local certifications. You can get a list of necessary local certifications and licenses from your local building inspector.

Try to find contractors with references. References are a great way for you to learn about the abilities of a contractor before you hire him or her. References can tell you everything you need to know about the professionalism, skill, and workmanship of the contractor. Contacting references can save you a lot of time, energy, frustration, and money.

It is advisable to ask for an estimate before you let the contractor start working. You should also remember that estimates are flexible and the price to go up or down a little.

Window installation contractors will generally ask you to pay a deposit on the work. You should only be willing to pay up to 25 per cent of the total estimated cost of the job. This is a standard amount that any reasonable contractor will agree to.