When you hire a window contractor, you expect the installation process to be quick and painless. In order to facilitate this, though, it is often helpful to run through some basic preparation steps. If you do, you will find that both the cost of your project goes down, and the potential damage done to your homethat wear and tear that happens when you have workers in your homewill be significantly decreased.
The Proper Workspace
Of course you have to consider the basics: how they get inside if you aren't there, directions to your house and where they will park trucks, but they will also often need a proper place to set up equipment (for a table saw or other tools.) It is always helpful to ask your window contractor what they will need in the way of workspace, power outlets, and parking. Remember, they will be making multiple trips between their trucks, an outdoor workstation, and the windows they are installing. The time it takes them, of course, adds to the cost of your home renovation project.
Easy Access
Consider where the window contractor will be working. How much room might they need (both inside and outside the house) in order to do their job properly? Is there any furniture in the way, perhaps a garden hose coiled outside or an expensive rug lying underneath the windowsill? Clearing away these spaces are simple steps that will allow the workmen to do their job without having to work with you simply to get started. You would much rather pay them to do their skilled craft rather than act as movers.
Protecting your Property
What rooms will the window installers need to move through? It is important to not only consider what is in their particular workstations, but what is between their workstations. Feet get dirty and sawdust gets dropped. One option is to ask that they bring drop cloths. Another option is to place old towels, sheets or carpet remnants on the floors or carpets you would like to protect. Similarly, if they are going to be cutting wood inside, you might want to cover furniture in your rooms. Many contractors will not do this automatically, so the impetus here is on you.
Like any other home renovation project, it is always best to have these conversations with your contractor before the crew arrives. If you can prepare for them, then you will be able to worry less about damage, and even cut down on some of the costs of the project. They, in turn, will appreciate your consideration. A happy contractor is a fast contractor. Remember though, once they are there, it is usually best to stay out of their way. Let the window professionals do their job. 
Brice Particelli, formerly a carpenter in Colorado and Kentucky, manages continuing education programs for Columbia University and is a freelance writer for both the home improvement and travel industries.