The basic rules of passive solar design are based on two facts: First, the sun rises in the east and sets in the west and second, the sun is higher in the summer sky and lower in the winter sky. The south side of a home always receives the most sunlight which is converted to heat inside the residence.
When possible, the longest side of the home should be oriented along an east/west axis allowing more of the home to face the sunny southern exposure. Homes designed for passive solar heating usually have large, south-facing windows to allow the warming effect from the sun during the winter months. Since the sun is higher in the sky during the warm months, properly designed overhangs, or the addition of awnings, can significantly reduce the solar heat gain during the summer. Windows on east and west facing walls should be reduced because it is difficult to effectively control the heat and penetrating rays of the sun when it is low in the sky. North-facing windows collect little solar heat, so they are used just to provide useful lighting. Even if your home cannot exactly face south, a variation of 20 -30 degrees of that direction will have minimal adverse effect.
Landscaping can also play a role in passive solar construction. Properly placed evergreens on north facing walls can buffer winter winds and harsh weather. Deciduous trees placed on the south, east, or west facing walls can shade your home in the summer months before dropping their leaves in the winter to let the sunlight into your home.
Whether you are building new or renovating, proper orientation reduces the need for auxiliary heating and cooling, resulting in lower energy bills and reduced greenhouse emissions.
Scott Allred is the owner of Precept Construction LLC. He can be reached at scott@preceptconstruction.com or 286- 6811. Please visit our website at www.preceptconstruction.com.
