eyebrow

An eyebrow is a small dormer window whose distinctive curved roof resembles a raised eyebrow when viewed from below. Unlike standard dormers with peaked or straight-sided roofs, the eyebrow features a convex arch that curves upward over the vertical face, then reverses into a concave curve where it meets the horizontal roofline at each end. This S-shaped profile creates both the visual effect and the structural logic: the curves distribute loads smoothly rather than introducing sharp angles that concentrate stress.

The eyebrow dormer is typically shallow, projecting only 2 to 3 feet from the main roof, and houses a single window or small pair of windows. It gained popularity in 18th and 19th century residential architecture, particularly in Colonial and Georgian styles, where it served practical and aesthetic purposes. The shallow projection means it sheds water readily without requiring complex flashing at multiple angles, and the curved roof minimizes visual bulk on steep roof pitches.

Construction and Material Challenges

Building an eyebrow requires custom carpentry. The curved roof structure must be formed with sprung rafters or laminated curves, not standard straight framing members. Roofers must shape shingles or tiles to follow the compound curves without excessive cutting or gaps; slate and asphalt shingles can be adapted, though metal standing seam roofing is increasingly preferred for its ability to conform without seams. The junctions where curves meet the main roof demand careful flashing design to prevent water infiltration at the valleys.

The name is straightforward: the shape resembles a human eyebrow. Because the design is inherently custom and labor-intensive, eyebrow dormers are now rare in new construction and primarily encountered in historic preservation and high-end residential work. When leaks or structural movement occur, remedial work requires roofers and carpenters familiar with traditional curved framing, making repair costly.