Square gutters create a clear eaves line and can work well with a metal roof. However, choosing them is not just a matter of shape. The cross-section, outlets, and the method of joining and fixing all need to be checked. A square gutter can be left visible or concealed behind a fascia cover. Each system has its own details. Installation rules for a round system should not be carried over on the basis of a similar size alone. Above all, it is about a defined appearance at the eaves. A flat front face can emphasise the horizontal line of the roof and echo the rectangular layout of the windows. It suits both tile-effect metal roofing and trapezoidal steel sheet, provided the overall design is well thought out. The shape alone, however, does not automatically mean greater capacity than any half-round gutter.