Planning to build a porch?

January 5, 2009

The stone house badly needs a veranda on the south side of the house to protect the doors and windows from the elements and reduce the amount of snow I must shovel each day throughout the winter.  The issue delaying plans has been the uncertainty as to how much a roof would reduce the light level in the house:  we have designed the entire interior around an effort to maximize natural light.

In a book on porch design I found the address of a website operated by the U.S. Navy which charts sun and moon elevation and azimuth for any American city at any time of day and year.

Minneapolis is at about the same latitude as Forfar.  On December 21st, the highest the sun will rise in the sky is 21.6 degrees above the horizon.  On June 21st, it will blaze down from 69 degrees.  Of course at that time it might be nice to have some shade, instead of  all of that light.

As usual, the devil is in the details.  A closer look will determine the precise direction of the sun at that time of day, and we should be able to to mock up a computer sketch which will provide optimum light and shade for the new veranda.

You can find the website at http://aa.usno.navy.mil/cgi-bin/aa_altazw.pl