When planning an extension, it’s easy to choose a roof lantern based on looks alone. In reality, long-term performance depends on how the system is engineered, installed, and how it behaves on a real UK roof. Many lanterns are adapted from conservatory systems, which can lead to issues later. Korniche roof lanterns are purpose-designed aluminium systems, built for flat roofs to deliver predictable installation, controlled performance, and reliable results over time.