A hip roof is a roof form in which all four sides slope downward from a central ridge or apex, with no vertical gable walls at the ends of the building. Understanding the hip roof's characteristics, advantages, and technical requirements helps homeowners working on extensions, loft conversions, or new builds make informed choices about roof form.

How a Hip Roof Differs from a Gable Roof

A gable or apex roof has two sloping sides that meet at the ridge and two vertical triangular end walls, called gables, at the short ends of the building. A hip roof has no gable walls; instead the two short ends of the building are covered by triangular sloping sections called hips that slope from the ridge down to the eaves at each corner. The result is a roof that slopes on all four sides and presents no vertical surfaces to the weather.

Structural Characteristics

Hip roofs are inherently more stable than gable roofs because the sloping hip sections tie the two main roof slopes together at the ends, providing triangulation that gable roofs lack. This makes them more resistant to wind uplift, particularly in exposed locations. The truss or cut rafter structure of a hip roof is more complex than a simple gable roof, requiring hip rafters, jack rafters, and a more intricate geometry at the hip junctions.

Common Variations

A half hip or jerkinhead roof is a variation where the upper portion of the short end is a small gable and the lower portion slopes as a hip. This provides additional headroom and window opportunity in what would otherwise be a confined hip end, while retaining some of the wind resistance benefits of the hip form. Hipped dormers project from the slope of a hip roof and require their own miniature hip roofs to match the parent roof form.

Hip Roofs and Loft Conversions

Loft conversions in hip-roofed houses are more complex and potentially more expensive than those in gable-roofed houses because the hip ends reduce the available floor area and headroom at the gable end positions. The most common approach is to replace the hip end with a gable wall as part of the conversion, creating a gable-end or hipped-to-gable loft conversion that provides a vertical wall at the end from which dormer windows can be fitted or skylights can illuminate the extended floor area. This type of conversion is generally permitted development but specific size limits apply.

Summary

A hip roof slopes on all four sides with no vertical gable end walls. It is more stable than a gable roof and performs well in exposed locations. Hip roofs are more complex to frame than gable roofs. Loft conversions in hip-roofed houses are more restricted in floor area and headroom unless a hipped-to-gable conversion is carried out. Matching hip junctions in extensions requires careful design and detailed planning.