Roof and Window Design

Alaskans are showing increased awareness that careful housing design can bring economies and pleasant living. Planning for the best relationship between roof overhang and window placement has caused several people to write or call for information on the elevation of the sun through the year. Usually people wish to build an overhang that lets sunlight stream into south-facing windows during the cooler months of the year, but which keeps at least part of the direct sun out during the hottest months.

The accompanying table gives the angle of the sun measured above the horizon at noon through the year. The angles, in degrees, are given for the twenty-first day of each month so as to show the extremes reached on the solstices, June 21 and December 21. The sketch suggests how to design a window and roof overhang relationship that best meets your desires. At the cooler or more northerly locations, one may be interested only in a roof overhang that never blocks out the sun, even on the hottest day.