Of course you can. What a question to be asking at this time. But just think of the possibilities. Just think about what waterproofed windows could achieve for you in your home or business. The obvious outcome is that it's going to be taking care of high levels of precipitation from the outside. Or rather, preventing such elements from entering interior spaces or doing damage to exterior surfaces even, including the windows.
In the context of this short industrial note, waterproofing windows remains a necessary and usual practice for commercial and building contractors. That is to say that they have their project management firmly intact. Right from the beginning, once a contract has been entered into with the client, an inventory of all necessary materials will need to be created. The list is functional and easy for other contracting parties to refer to.
Or so it should be in the proactive world of successfully completed building construction work. Pre-prepared materials, tools and (ideally) portable machinery are always good to go. But the well prepared contractor knows that each project should be different. Provision is made for this and any additional expense thereof (say, the hiring of new equipment and/or materials not utilized regularly) needs to be factored into the contract price.
It is generally a competitive quote that is offered to the client. He is made fully aware of any future expenses and if he should deem the expense impractical and unsuitable to his budget status, he needs to be firm in advising his contractor thereof. But this will always have to be done within reason. While the contracting consultations are generally given free of charge, contractors and project managers still bear the responsibility of potentially huge expenses leveled on their shoulders.