Sustainable Ramona Salutes

Rob Lewallen

Sustainable Houses

Example: His Truck Trail House

Rob Lewallen has a 40-plus-year history of experience at designing and building energy-efficient homes. And for his own house—the Truck Trail House—he was able to “do it best” when he rebuilt a sustainable home that was destroyed by fire–twice. In 1978 he built a barn, which he eventually converted to a house. Unfortunately, the house burned to the ground in 1981. He designed a new house, which burned down again after 26 years from the 2007 wildfires. He’s rebuilt again but now rents out the third house.

Take Advantage of What Mother Nature Offers

Rob has several concepts he uses to build a sustainable home in our local climate: First, use what Mother Nature offers. For example, position it south sloping, with windows utilizing “optimum overhangs” to keep cool in the summer, but allowing low winter sun for passive solar heat. Use the asset of hot water rises for gravity-fed re-circulation by installing a gently up-sloping pipe to go from the hot water heater to the faucet farthest away with a circulation loop back to the HW heater.

Second, use earth’s temperature to cool a house. “The most sustainable house is a cave, which has very stable temperatures, so I design above-ground caves.” Building part of the house underground enables warm or cool temperature control using thermal mass given that the temperature is always 54 degrees 6 feet underground in this latitude. Build partially underground–a concept he likes to call semi-subterranean embellished with a stair-step foundation of vertical concrete underground sections. In some houses that he’s built, he installs a ”Cool Pipe” by digging a 6 feet deep trench about 100 feet long using prevailing winds and/or fans to draw the cool air into the house and then tie it to a rock storage bin. “It’s free air-conditioning! That’s new technology from 3,000-4,000 years ago.”

Third, since hot air rises, design with vaulted ceilings and position windows to let hot air out. Prevailing westerlies provide cool air. In the winter, close those widows. Reverse ceiling fans to blow hot air down to lowest point.

All three of the Truck Trail houses were built to take advantage of Mother Nature. The current house on the 10-acre west Ramona hill site faces south with a view of the ocean. Rob built the house (all 3) to appear like it was flowing out of the mountain. The north elevations are semi-subterranean for temperature stabilization. The house has passive solar heat gain, a high-efficiency FPX fireplace with a high SEER back-up heating pump. To take advantage of thermal mass, he left one of the large boulders exposed in the interior that blends into the design.

“Insulate the heck out of it!”

Insulation is a critical element in creating an energy-efficient design, working in conjunction with the thermal mass, i.e., the ability to store heat/cool to prevent temperature fluctuations. Combined with the use of concrete floors, insulation provides key assistance to keeping a house at the desired temperature. Double or even triple-paned windows are critical. The Truck Trail home has triple glazed glass.

In the Truck Trail house, Rob used 44 insulation in the ceilings and R-21 in the walls. To keep the benefit of the concrete floors, he used concrete tiles to maintain earth temperatures. “You don’t want to insulate your thermal mass from the earth by using carpets or anything that can insulate from your thermal mass.”

Use Renewable Energy: Solar Panels

Rob used two different kinds of solar panels for his house. One type heats the 120 gallon hot water tank while the other 28 photovoltaic panels provide all of the electricity needed.

The Sustainable Garage

Rob also built a detached, sustainable cave-like garage. It’s a large 3-car of almost 900 square feet facing south, semi-subterranean, and sunken into the side of the mountain. Most of the garage is 15 feet below surface grade with 3 feet of soil above the I-beam roof structure. The south-facing walls are covered in natural stone from the property. Round clay “Canales” drain the roof to the front when it rains.

Sustainable Ramona is pleased to salute Rob Lewallen and all he’s contributed as part of its month-long Earth Day highlight of those in Ramona who have provided sustainable efforts.\