Fixed shading devices are usually external and highly visible and can provide important architectural opportunities. Typically they are in the form of horizontal overhangs, vertical fins or egg-crate (combined horizontal and vertical) devices. The recessed window is also a type of fixed shading device.
In fixed shading device design the orientation of the aperture is the main determinant. When correctly designed and used on the south-facing facade, the horizontal overhang can provide complete shading during midsummer and permit solar penetration in winter. To be most effective (i.e. to better control low-angled morning and afternoon sun) the overhang should extend sufficiently on both sides of the window aperture. The overhang length is determined by the width of the aperture and the latitude. The depth is determined by latitude, window height, and the vertical distance between the window and the overhang.
Fixed devices do not provide effective protection from the low-angled sunlight of morning and afternoon, particularly on the east and west facades. Fixed vertical fins tend to reduce internal illuminance.