One of the smartest and most cost-efficient upgrades you can make to any home is replacing the windows. It not only creates an extra layer of energy efficiency and effectively reduces your utility bills, but it also adds a TON of value to your home and makes your house more attractive from the curb. However, this process can be a real pain. Here are 9 common Colorado window replacement mistakes that you should definitely avoid. Window Replacement, Complicated? Yes, it seems like a very straightforward and easy process, but unfortunately, it’s much more complicated than removing old windows and replacing.