My home and yard design incorporated solutions for passive solar gain (zero when I began), water management (the lot had terrible flooding problems), soil development (the lot is entirely granite), food and herb production, flower and evergreen gardens, wildlife habitat, native drought-resistant plantings, windbreaks, views, animals, human activities, and more.
I’ll share two of those aspects here: Solar gain and water management.
My house – I often called it “the ugliest house on the block” – was purchased primarily for its passive solar potential as well as its affordability.
The south-facing windows were unfortunately shaded by a 6-foot eave, and some windows had been covered entirely with exterior siding – negating all its wonderful passive solar potential.
I hired a handyman to uncover some of the windows and enclose the existing front porch into a sunroom for passive solar gain. Even though the new room is only 3 1/2 feet wide, it serves as a pleasant sitting area, entry way, and room for drying food and seed starting.
SOLAR GAIN, WINTER:
On the Winter Solstice at noon, the sun now enters 90% of the windows. (These were salvaged windows. Ideally, they would be slightly smaller so no part of them would be “wasted,” but the money and environmental savings in using local salvage warrants the small loss of heat at nighttime that the extra glass creates.)
The daytime solar gain helps substantially to heat the house when the doors and windows are simply opened from the house to the sunroom on winter days. The BTU’s are estimated to equal $25 per month in gas, more in electricity.
I plan to upgrade the design by adding air vents between the house and sunroom at floor level and near the roof of the sunroom to facilitate the cycling of hot air without opening the door or windows.
Two more upgrades will be to install solar blinds (to hold heat in the sunroom on winter nights) and medium-colored tiles on the floor. Tiles will provide “thermal mass” – one of the three essential elements for passive solar design besides solar gain and insulation. Thermal mass transforms light into heat and absorbs some of it, reducing the air temperature somewhat during the day and saving it to slowly release at night – moderating radical temperature swings.
SOLAR SHADE, SUMMER:
On the Summer Solstice, the higher Sun puts the windows in full shade all day at this latitude.
Adding Thermal Mass to complete the Passive Solar Design
Thermal mass is essential to a passive solar home, though it is often, sadly, not understood and neglected.
Thermal mass is anything that has mass – substantial enough to hold heat; these include adobe, plaster, concrete, tiles, and even water. They all help stabilize temperatures, keeping the house cooler in summer and warmer in winter. When heat is stored in the mass, rather than in the air, it can be slowly released during the night and not lost when doors are opened.
Natural plaster artist Gavio helped me to create wall sculptures and finishes from natural adobe plaster, for which I’ve brought over two tons of adobe into the interior, and plans for more! The home stays comfortable year-round, with very little swings in the temperatures or utility bills!
Both tree sculptures were crafted of tree branches covered or partially covered with adobe. Each room has one wall with 2-3″ of adobe laid against either 14″ of solid concrete or standard cinder blocks. Insulation on the outside of the house keeps this wealth of stored heat on the interior.
This banco (bench, below) and firewood storage were created of broken bricks and scrap lumber covered with adobe. In this photo, they await their final coat of “refined adobe,” for which every ingredient is sifted to a specific size, to create a smooth finish. (They’re finished now. Need a new photo.)
This home was originally a store with extremely simple rectangular architecture. Natural plaster obviously has wonderful potential for transforming a boring space!
Topography & Water Management:
This property drops about 14 feet (!) from the top of a granite hill cutaway on the northwest corner down into the side yard, which then slopes gently, dropping a foot and a half across the front of the house to the southeast/front corner of the lot.
Silver City, New Mexico, receives approximately 16 inches of rain per year, which can be harvested with this 1,200 square-foot roof, yielding up to 12,000 gallons per year. One-third of that – 4,000 gallons – comes in the month of July. That’s a lot of water to deal with at one time.
The most significant water problem had been created by the house’s roof whose shed design and single gutter in the back sends the vast majority of any rainfall to the northwest corner of the house and into the western side yard. I improved the slope of the side yard, reversing the grade away from the house and toward the hill, and moved the downpour of gutter water along terraces built against the hill, then back across the length of the yard alongside other gardens.
Above: 2006/7, after regrading and building terraces. (The swale is there, in front of the terraces, but hard to see in this photo.)
Below: 2013, after plants have grown and a patio has been poured. The swale manages all the water that pours off the roof. (Click here for a 1-minute video of the swale in action during a downpour.)
I replaced the roof with a steel one and installed a 300-gallon water tank beneath the main gutter with an overflow that pours into the swale beside the tank. More water storage would be preferable, but the space between the back door and hillside simply won’t allow it.
The chain (below) is attached at the gutter edge of the patio to move rainwater more efficiently and less obtrusively than a downspout.
Notice three terraces of plantings all accessible from the brick patio edge.
The swale turns at the western boundary (just beyond the left edge of this photo) where an apricot tree thrives. Then the swale travels back east alongside more gardens to the opposite property line. Sized and sloped properly, the swale contains all the water from the heaviest rains, storing it all in the soil near plants.
Other aspects of this home and garden design include: soil analysis, plants, animals, wind, cold air drainage, privacy, noise, human and business activities (workshops and socializing), and views.
Integrating the various energies – during all seasons and over the decades – into a single evolving design is the challenge – and the fun!