At Allegiance Windows and Doors, we know that not every home fits into standard window sizes, and homeowners with arched, circular, oversized, historic-style, or architecturally unique openings often struggle to find installers who can deliver the right fit and finish. Off-the-shelf solutions rarely work in these situations, and forcing a stock window into a custom opening creates aesthetic and performance problems that only get worse over time. Specialty and custom-measured windows exist exactly for this reason. They allow a home's architectural character to shine while delivering modern efficiency and durability.