Published in Su Casa Magazine, Summer 2003 www.sucasamagazine.com
Unlimited Access to Healthy Living
by Catherine Wanek
After a lifetime of living in and adapting to homes built by someone else, my mother Betty, at age 71, began contemplating building a home of her own design. At first the choices were overwhelming. But gradually she began to really enjoy the process of answering the question “What do I want?”
Foremost on her list of requirements was accessibility. My father’s mobility had over the years become limited, and soon he would need a wheelchair to get around. She wanted to create a space that he would be free to move about, indoors and out.
The project was a summer home in the foothills of the Gila National Forest in southern New Mexico, on a hillside lot next door to my home and business, the Black Range Lodge. The cool mountain climate would be a seasonal respite from their retirement home in central Arizona. Our Lodge – fashioned from stone and logs in the 1880s and the 1940s -- has narrow doorways, floor levels change abruptly, and all the guest rooms are on the second floor. It has a lot of character, but is not exactly “wheelchair friendly.” My husband Pete and I were eager to help create an accessible guesthouse where my parents could comfortably visit in the summer, with the plan that the rest of the time it would be available to our “bed and breakfast” guests.
A Non-toxic Natural Home. Already we were advocates of straw-bale construction, having built a post-and-beam-and-bale greenhouse (and produced a video about it). Straw bales make a sturdy building block that provides a super-insulated wall system. They can emulate the aesthetics of solid adobe walls for less cost and with better energy efficiency. My mother liked the idea of utilizing an agricultural waste product, saving trees and saving money on energy bills, so she readily agreed that the house should be built with bales.
Strawbale is like a doorway into ecological building, so we had already learned about many aspects of conventional construction that can impact the health of homeowners. Modern building materials such as plywood, wood-chip boards and fiberglass insulation are held together with formaldehyde and other toxic glues that negatively affect indoor air quality. Formaldehyde is also found in carpeting, which off-gasses for weeks after installation. That wet-paint headache comes from “volatile organic compounds” (VOCs) in the paint formula. Foam insulations, PVC, and vinyl are fairly inert -- unless a fire starts. When they burn these materials release poisonous fumes.
“Sick building syndrome” is not only a product of modern materials, but of naturally occurring “biological air contaminants.” The vast majority of molds, fungi and bacteria are benign, but a few, such as the black mold Stachybotrys, can make you sick with flu-like symptoms. Mold and mildew thrive in moist, warm, dark places and require food. Wet cellulose building materials (carpeting, particle board, drywall, straw, etc.) can provide a good growing medium. So can the lint that collects in dark, moist heating and ventilation ducts. Also, naturally occurring dust and pollen are allergens, which can cause allergic reactions in sensitive individuals.
The air-tight homes commonly built these days can exacerbate these problems, often resulting in the air inside our homes being far more polluted than outside, even in urban areas. My mother agreed that choosing non-toxic materials and reducing the likelihood of mold and allergens were a high priority -- so the search for natural building products and systems was on.
Let The Sunshine In. The house design evolved from the site, a 30% slope facing north – the opposite of good solar orientation. But the benefits of building on this hillside were the beautiful views and privacy it afforded. To disturb the existing landscape as little as possible, we selected a natural clearing and dug into the hillside to create a split-level structure.
The top level is a spacious one-bedroom home with an open floor plan, designed expressly to be wheelchair friendly. A wrap-around deck sticks out of the hillside to take advantage of a wide view of the mountains from east to west. It can be accessed from the front, the kitchen and the bedroom, through wide, zero-step doorways.
The downstairs is like a day-lit basement, divided between a studio apartment and a large equipment/storage room. Because a stairway takes up so much room inside, the upstairs and downstairs are connected via concrete stairs around the outside. The result is two separate, versatile spaces in under 2,000 square feet: the studio apartment works for visiting family and friends (or potentially a caregiver) while the upstairs is a luxurious cabin in the woods, with killer views.
Betty’s design parameters included taking advantage of these views, while capturing as much solar gain from the south as the site would allow. Since ultraviolet light and oxygen are naturally antiseptic, allowing sunshine and fresh air into the home helps sanitize the indoor environment. Betty considered where in the house moisture could build up -- like the bathrooms and laundry room – and planned ventilation accordingly. A window that opens and/or an exhaust fan in these places will allow humidity to escape, and typically is enough to eliminate mold habitat. She also selected openable windows to catch the prevailing west-to-east breezes for passive cooling.
Strategies for accessibility went beyond 36-inch-wide doorways and smooth, level floors. The bathroom has a large roll-in shower, a center floor drain, and a pedestal washbowl that allows a wheelchair to roll up underneath. One clothes closet has lowered shelves and shirt pole. Most electrical switches are three-way, with receptacles about three feet up from the floor. Kitchen base cabinets have full access drawers with storage for china, cups, pans, etc. and the stove has controls on the front. Plus the dining countertop is positioned at wheelchair height with a nearby TV on an adjustable wall bracket. These selections added little to the cost of the home, as they were included during the design phase.
Choosing natural materials. To create the post-and-beam structure we used ponderosa pine and local juniper trees wherever it was practical to expose their organic beauty. We harvested them ourselves on nearby national forest land (with a permit, of course). They were mostly young trees, taken from a stand of pines that needed thinning, and were carefully peeled and sanded to retain the character of the individual trees.
Rough cut dimensional lumber was used for window and door framing, and where the structure would be buried inside bale walls. Straw bales are roughly equivalent per inch to fiberglass batt insulation, but three times the width of a typical 6-inch stud wall -- so bale walls are pleasingly thick and “super-insulated.” Above the ceiling, my mother installed Miraflex, a spun fiberglass insulation that doesn’t have the “itch” of fiberglass batts, nor the formaldehyde content. (Had it been available, she might have chosen Ultratouch, a new cotton batt insulation made from post-industrial blue jean scraps. Blown cellulose, made from recycled newspaper, is also non-toxic, though can act as an allergen.)
Eschewing carpet, Betty chose easy-care tile floors in the bathroom and concrete floors for the living/dining rooms. These she colored herself, with multiple applications of ferrous sulfate – a benign, inexpensive fertilizer that stains cement a copper color. Cracks in the monolithic slab were filled with grout, and also stained, then the concrete was sealed with a water-based sealer. The floors turned out with the color and character of shiny, aged leather.
Bale surfaces were plastered inside and out with two coats of cement/lime stucco, and a third color coat on the exterior. The final interior finish is a luscious polished aliz (clay slip). Clay plasters are praised for absorbing odors and softening sounds, and they will also moderate humidity inside homes due to their enormous capacity to absorb and store moisture from the air. Earthen plasters can often be made from on-site soils, and be applied safely with bare hands and without protective eye ware. (They are so benign, you can give yourself a facial at the same time.)
Master plasterer Carole Crews led a fun-filled workshop, supervising eager students in the application of the finish plasters inside Betty’s house. Ingredients included white kaolin clay, natural pigments, plaster sand, wheat paste (as a hardener),plus mica and finely chopped straw, for sparkle and texture. Mixed on site to the consistency of a thick milkshake, two coats of aliz were painted on the stuccoed wall. When almost dry, it was polished. This non-toxic natural plaster is traditional on adobe, and it produces a beautiful, smooth, dust-free finish that needs no further decoration.
Choosing Natural Systems. My mother also decided on a radiant floor heating system instead of forced air heating and cooling, as duct work provides habitat for microbial growth. Although more modern HVAC systems offer excellent filtration for tiny particles, without regular maintenance they can actually blow moldy dust particles directly into your living/breathing space. Radiant floor heat is silent, can cost less to install and operate, and requires no duct work.
Imbedded inside the concrete floor is a continuous loop of “PEX” tubing, which circulates hot water through the insulated slab, warming the living space through radiation. It produces a quiet, comfortable heat that envelopes the space with warmth. Pex is a durable, polyethylene tubing, which comes in rolls like garden hose, and is made by a variety of manufacturers. (It can also replace copper and PVC in domestic hot and cold water plumbing systems.) Our mountain climate and passive cooling strategies virtually eliminate the need for a cooling system within the super-insulated strawbale, so there is no forced-air ductwork anywhere in the house. And when my father comes to visit, guess what? His long-standing dust allergies disappear.
Finishing Touches. Throughout the home we also wanted to demonstrate the sculptural qualities of the walls, and the bales themselves. Although the structure is rectilinear, the walls curve around to create an intimate oval shape to the dining and living rooms. Decorative nichos and a truth window are carved into the bales, and their aliz finish sparkles subtly throughout the day as the light moves across it. Despite the many challenges of design and construction, my mother, the perfectionist, confessed, “It is actually better than I anticipated.”
She continues, “I take enormous pleasure from seeing how this home affects my disabled husband as he enjoys not only the convenience of the floor plan, but the air quality of every room. His allergies are easily triggered, so this home -- so easy to maintain dust, odor and mold free -- is a special place for him. He loves the fresh breeze from open windows and the morning sun from the huge east window framing the view of Star Peak. He can wheel around the deck following the sun, or not, watching birds as the light moves across the landscape. And the beauty of the natural logs, wide straw-bale walls and deep window sills are simply relaxing. It’s our version of a retirement dream house.”
Catherine Wanek organized the building of a straw-bale greenhouse in 1992, and has been an advocate ever since. She’s traveled from Orange County (California) to Red Square (Russia) to document the straw bale movement. Along the way, she produced four straw bale videos and spent five years managing and editing The Last Straw, the International Journal of Straw Bale and Natural Building. Catherine also co-authored The Art of Natural Building (2001), and wrote and photographed The New Strawbale Home (2003).