In many cases, custom guillotine, tilt, or sash windows (or custom made windows in general) are much easier and quicker to install compared to stock windows. This is mainly because they are made according to the specifications of the opening, thereby reducing the need for modifications during the installation.
When you hire a professional contractor for your custom windows, you can be sure that they will take the exact measurements and build your windows according to these. This ensures that the windows, once completed, will be installed on the day that they are delivered. Because of the exact measurements, there will be lesser need for preparing the installation site, and eliminates the need to create or widen the openings, or adding caulking or filling gaps. This will reduce the time and labour needed to install the windows, and therefore help you save on labour expenses.