Roof Overhang Shading

The roof overhang is too wide.

Roof overhang shading.

For hot humid climates and hot dry climates with no heating requirements shade the whole building at all times with eaves overhangs of 50 of height from floor level to both north and south where possible and use planting or adjoining buildings where it is not possible. For hot dry climates with some heating requirements gradually increase the overhang up to 50 of height full shading. How roof overhangs or other window overhangs work to control heat and solar gain. There are two common problems encountered with roof overhangs.

The depth of roof overhangs is crucial in cold and moderate climates where oversized overhangs will have negative side effects. A value of 73 for example indicates that the overhang is shading about 27 of the window area and 73 of the window is in the sun. The shade is in 1 increments. Shade each data cell has the percentage of shade listed in addition to the background color as an indicator.

The following snips show shading at noon on april 16 june 21 september 1 december 1 and february 1. No i just made the overhangs wide enough to provide the extra shade. You may use wide overhangs and verandas in hot climates without a cold season and in hot wet climates with high levels of rainfall but oversized overhangs in other. The sun is in 1 increments.

An overhang or some sort of solar control or solar shading is a crucial element in passive solar design because it blocks the sun s heat energy when it is not desired. Overhang depth for solar heat gains and shade. The roof overhang does not extend far enough. Using sketchup i just fiddled around with the overhang width window size and vertical placement until i got the desired shading effect.

Overhangs are most effective for south facing elements in the northern hemisphere and at midday. Because the sun travels different paths across the sky in the winter low and summer high time an overhang can be constructed to utilize and manipulate the heat energy from the sun. This leads to a situation where there is an excess amount of shade and the exterior of the home appears dark and gloomy. In passive solar home design exterior roof overhangs provide a practical method for shading building elements such as windows doors and walls.