Property Site Planning Around the Sun
How I Retrofit My Properties to Use the Sun
Story & Photos By Ben Hoffman, Maine
Many years ago, I borrowed a book from a landscape architect and remember a paragraph in the preface about how the prairie dog chooses its home site. We humans can learn a lot from the prairie dog, which usually picks the southwest slope of a hill, for two principal reasons.
First, that aspect gains the most solar insulation to keep him warmer in winter. Second, most prevailing winds come from the northwest quarter.
Conventional wisdom says a house should face the street. Take a look at the west side of my house that faces the street; it has no windows on the south and two on the north. No solar gain and some frigidity gain in winter. With 40 feet facing the wind and 24 feet facing the sun, it is a big energy loser. When built in 1978, it faced a country road that soon became a state highway. No vegetation to block wind or road dust and noise. Just think how much better if the original builder had faced the house south—40 feet of south-facing wall would have increased solar gain by 5/3 (40/24). By reversing the floor plan, north-facing windows would face east and no windows would face the wind. We had lived next to this house for nine years and bought it by email in 2001 from Alaska. We could not turn it to face the sun, but we could make some changes.
Federal law did not permit 100,000-pound loads on Maine’s northern interstate, so loaded log and chip trucks rolled by our house for 12 hours a day, beginning at 2 a.m. Empties returned on I-95. The noise, vibration and dirt were not pleasant. Planting shrubs in the front reduced those problems somewhat and Congress finally authorized 100,000-pound loads on I-95. We made a few additions, first an arctic entry, then a summer porch on the east (quiet) side, and eventually a master suite on the north (with doubled stud walls and extra insulation facing the highway). And when the drive was paved, by sloping the sub-grade to the south, solar energy melts snow and ice in winter (and water runs away from the house).
Our farm in central Vermont was on both sides of a north-facing valley. Fields on the east side (facing west) warmed up early in spring, but our house and east-facing fields were slow to warm up. The penalty was cutting and splitting more firewood. When we moved to Maine, our farm was level, but had a slight north slope; hence, the fields do not warm up in early spring. Fortunately, the old-timers laid out the house/carriage shed/barn in an east-west direction. Maximum exposure to sun, minimum to wind, and barn smells were carried away by wind. We used to butcher broilers in the east doorway of the barn—cool breeze, no flies, and guts and feathers into the manure pile.
We really learned about site planning in Alaska. We had a possible site slightly north of a small volcanic ridge, surrounded by white spruce trees, with a spectacular, 180-degree panoramic view of the snow-capped Wrangell-St. Elias range. With a borrowed backhoe, I dug a test hole in mid-August, hitting permafrost at 13 feet. I wanted a log home with an insulated, Permanent Wood Foundation. Wrong place! So I went to the south side of the ridge, surrounded by quaking aspen trees, with a nice view of the Chugach Range.
Interesting situation. I studied the sites with a color, infrared aerial photo. The north side of the ridge was blue (cold) and the south was red (warm). Why? The summer sun angle in Alaska is very low, barely enough to melt the upper permafrost on level ground. Drive east on the Glenn Highway from Anchorage in early spring—north-facing slopes show a tinge of pink (white birch) and south slopes a tinge of green (aspen). And the difference between my possible house sites? The north site was colder and damper, with more mosquitoes (the state bird), while the southern site was warmer, drier, had fewer mosquitoes, and leafless-in-winter aspens let more sun onto the house.
When we lived in Alaska, we had an arctic entry (called a mud room in the lower 48) on our cabin to keep the -55°F outside air (not much mud) out of the house. When we knew we were coming back to Maine, we bought the house next door to our former farm by email. We moved in around November 10. That south door opened right into the dining area, allowing cold air to chill your soup. The first thing I did was add a closed entry, fortunately, after visiting a friend’s sunroom and deciding to fancify the addition. The 12-feet by 16-feet addition rests on tapered frost piers and went through the first winter with plastic over the window openings (pending a Home Depot window sale) and Grace Ice and Water Shield for a roof. I got sticker shock over $450 triangular windows and made them in my shop.
Some early remodeling—removing the partition between the kitchen/dining and living areas—revealed that this was a modular home. I salvaged OSB from the partition, ripped it into 14-1/2 inch strips, nailed cleats to the bottoms of joists, dropped the OSB between the joists (to keep varmints out) and filled the space with insulation. Once the windows were in we experienced mid-winter temps of 80 to 90 degrees by noon, I opened the door to let the hot air into the house and frequently ate lunch on the porch.
The “sun-porch/arctic entry” serves many uses. Cabinets under the windows on three walls provide plenty of shelf space for my wife’s geraniums and for starting seedlings. A closet on the house wall adds storage space and a pantry, and the east wall became the site of our solar system controls. In addition, it intercepts mud, sawdust, chainsaw chips and grain chaff from our outside activities. The floor was done with carpet tiles that are easily replaced when soiled or mutilated. Initially, we used an unvented propane heater to maintain 55 degrees at night but the noxious fumes ruined our plants. A vented Rinnai now keeps it warm at night and half-inch insulation panels fitted to the windows reduce heat loss on cold nights.
You may not be able to change how your home is sited, but you can add shrubbery to change the windy side microclimate. Also, consider adding a windbreak/storage room to your home, even if you’re in Georgia. And if you are starting anew, don’t use cut wood, as it often takes more BTUs—more wood cutting and splitting.