With its Old World architecture and angular shapes, Elliot Johnson and Lisa Chronister’s cast earth home in Austin, Texas, looks like it came straight from the pages of a storybook. “French Country is very popular around here,” Lisa says, “but we wanted something else. We wanted a castle.”
Elliot, an architect, and Lisa, a reference librarian at a community college, wanted a home that reflected their values. Winner of the 2008 MAX Award (Marketing Award for Excellence) for Best Green Home, Elliot and Lisa’s eco-conscious “castle” includes a photovoltaic solar system, a thermal chimney for natural cooling, a tight thermal envelope and almost all salvaged interior materials.
The couple spent six years looking for a lot—with character—and three more years developing their English manor. The 1,547-square-foot home rests within a highly sloped, northeast-facing 5-acre terrain of Texas cedar trees and fine Spanish Oak trees, which proved challenging to build on. “We had a hard time convincing contractors to drive onto our lot with a crane,” Lisa says. “One time Elliot even had to drive a delivery person’s truck onto our lot because they wouldn’t. But it can be done.”
Once Upon a Time
After more than two years of carefully clearing the heavily overgrown lot, Elliot and Lisa started building. Elliot created an open floor plan that made it easy for spaces to flow into one another: The kitchen area leads into the family room, which leads into the breakfast room. Placed beneath 10-foot ceilings, the design makes the space seem larger than it really is.
To manage the hot Texas summers without guzzling energy, the home-owners installed a thermal chimney and a photovoltaic system. The thermal chimney harnesses natural convection—the principle that heat rises. Leading through the home and out the highest point, the chimney releases hot air through vents in a cupola at the top of the home and pulls cooler air in through the lower windows. The photovoltaic system saves about $500 a year in energy costs.
To further increase energy efficiency, Elliot installed spray-foam insulation in the roof deck rather than in the ceiling, where it’s typically done. “This is the most energy-efficient thing you can do to a home in this type of climate,” Elliot says. “It puts all the duct equipment inside the thermal envelope.” In a typical home, insulation is placed in the ceiling, which creates a pocket of hot air (up to 120 degrees) in the attic where ductwork is located. Insulating the attic allows the equipment to run more efficiently. Heating and cooling equipment also work more efficiently if it’s the correct size for the home, so Elliot and Lisa hired a home-performance specialist to help them choose their HVAC unit.
To decorate their English manor, Elliot and Lisa scoured Texas for recycled and salvaged materials. Besides being eco-friendly, this also made for interesting, unique décor. Some of the couple’s favorite features include the hand-plastered walls, granite countertops, a cast-iron pot rack hanging over the countertop, a copper sink from Mexico, cabinets from one of Elliot’s remodeling jobs, the year-round porches and the built-in bookcases—all of which were made with recycled and reused materials.
After taking stained-glass art classes for recreation, Lisa constructed stained glass windows and doors for her home. This was a daunting task; she spent 200 hours finishing a single panel, but she continued making pieces and integrating them throughout the house. She installed stained glass in a pair of 100-year-old, mahogany French doors from Argentina that the couple stumbled upon at a local salvage store. This piece quickly became one of the couple’s favorite elements.
Happily Ever After?
As the first builders in Austin to use cast earth, Elliot and Lisa learned that, though beautiful, environmentally conscious and economical, the material does not perform optimally in their hot, humid climate. Cast earth is made with earth and calcined gypsum, which is poured into place like concrete. It allowed Elliot and Lisa to achieve the look and feel they wanted—walls covered in 24-inch-thick limestone—but it also created many challenges.
Cast earth, which has a high thermal mass, performs best in climates with a high diurnal swing, meaning daytime temperatures are high while nighttime temperatures are low. In this situation, cast earth regulates temperatures by absorbing daytime heat and releasing it at night and storing nighttime coolness through the heat of the day. Because Texas summers are pretty much just hot—during the most intense month of building, temperatures hit more than 100 degrees every day and dropped to around 90 degrees at night—the cast earth can’t work as effectively.
Though the couple is happy with their decision to build using cast earth, Elliot recommends others in hot climates consider ICFs (Insulating Concrete Forms), which provide both strength and insulative qualities. “All green products have shades of gray,” Elliot says. “While we chose cast earth to reduce the use of trees and because of a lifelong desire to have an earthen house, for Austin, there are better alternatives.” The couple plans on using ICFs for their home additions.
After working on the home for almost three years, Lisa and Elliot still aren’t finished: Over the next several years, they plan to add three more structures that will radiate off the central part of the home. The new buildings will house Elliot’s office, space to accommodate houseguests, a master bedroom, a library, and a formal living and dining area. “This is typical of an English Tudor, which is usually added on to over 300 or 400 years,” Elliot says. “We often get asked how old our home is, even though it’s only three years old. We’re glad that it looks older. That was our goal.”
And if you would call this home fantastical, that suits Lisa and Elliot just fine. “We would always joke we were going for a Rivendell look from Tolkien’s Lord of the Rings,” Lisa says with a laugh. “But I don’t know if we quite succeeded in that.”
A Chat With the Homeowners
What was your major influence when building this house?
Elliot Johnson: I have long believed that architecture should be about more than just form and function—the homes we create should offer excitement and drama.
Lisa Chronister: English and Norman manor houses and castles. I love Old World, medieval and Renaissance architecture, and I wanted a home that reflected that.
What advice would you offer new home builders?
Lisa: If you really want the house of your dreams, you should be prepared to spend a lot of time on it. We read a lot of architecture books and magazines, went to home tours and shopped at dozens of places for interior finishes. We probably changed our minds on floor plans and finishes a dozen times between the design and completion of the house. It can be very frustrating at times, but in the end you get a home that’s exactly what you want.
Did searching for salvaged materials add a lot of time to the process?
Elliot: It did not delay the process, but it is a lot of work. For instance, finding nice salvaged doors took an all-day trip to Houston. Also, there was a lot of extra work involved in preparing the doors for the finish.
What’s your favorite fairy tale or storybook?
Elliot: We have been enamored with J.R.R. Tolkien for probably 30 years.
What book is on your nightstand right now?
Elliot: I read a lot of science-fiction/fantasy. Right now I have the finale to a series by Kevin Anderson, The Saga of Seven Suns: The Ashes of Worlds (Orbit, 2008).
The Good Stuff
? Cast earth walls
? Spray irrigation septic system reuses household water for landscaping
? Energy-efficient, low-emissivity glass used in all windows
? Benjamin Moore low-VOC paints (VOCs are volatile organic compounds that outgas)
? Low-flow shower heads and toilets
? 3-KW photovoltaic system, which saves about $500 a year in utility bills
? 100-year-old salvaged French doors originally from Argentina
? Cedar trees from site used to construct columns on deck, walkway and fencing
? 14.0 Seasonal Energy Efficiency Ratio (SEER) perfectly sized A/C system
? Massaranduba (Brazilian Redwood), which requires no maintenance, used for porches, fencing and walkway
? Thermal BioBased Spray Foam Insulation in walls and roof system
Architect: Elliot Johnson
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