Placing the house on a lot: Sun and Moon plus SunCalc

or optimal performance Northern Hemisphere homes should have as much glass surface as possible facing south and a minimum of doors and windows facing north side. This allows homeowners to capture the most amount of the sun’s energy and efficiently place roof solar collectors, water heaters or other solar energy devices.

But there are times when the positioning or characteristics of your building lot does not allow you to perfectly locate it along the North-South axis.  So there is this handy tool available on your iPhone or android phone called Sun and Moon.


Sun and Moon Application:  showing location of the Sun at different times of the day (Nov 21,2016)

With the help of a compass it will indicate where and at what time the sun will come out and set in that particular spot.  This is invaluable because if your lot has obstacles (such as a big tree) you can accommodate the home axis to prevent ideal sun from penetrating key rooms in the house such as the living room, sunroom, etc.

While Sun and Moon is a practical tool to use while you are AT the site you might LATER want to check out SunCalc on your desktop.  SunCalc is a much more detailed application because it overlays a Google map and it has a field to enter a specific date and see how different seasons affect the homes sunlight.  You can see sun positions at sunrise, sunset or any specified time.  It shows sun trajectory and variation of sun trajectories during the year. The closer a point is to the center, the higher is the sun above the horizon.  My suggestion is to enter dates that are 90 days apart to make sure you see how  each season’s sun angle affect your home (January 1, March 1, June 1 and October 1).


SunCalc readout for the World Trade Center Memorial Foundation on June 8, 2016.  It indicated sunrise at 5:26 AM and sunset at 8:23 PM

A professional can use SunCalc to adapt the architecture of a new home.  If for example you plan on building a SUMMER home that gets little or no use during the other seasons, you want to make sure you not only have a southern facing living/family room but one that has large roof overhangs over southern-facing windows to prevent the summer sun from overly heating these rooms.    Conversely if you are building a house in a ski location that gets most of its use in the WINTER you want a modern house with little or no roof overhang so your southern-facing gets the most amount of sun and its heat.





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