su libro

guided reading Learn how to live in the round, travel the historic Camino Real, and design a cozy (and cool) passive solar house.
By Charles C. Poling

This article first appeared in Spring 07 Su Casa

Yurts: Living in the Round, by Becky Kemery, Gibbs Smith, Publisher, Layton, Utah, 150 pages, paperback, $24.95.
My experience with yurts is limited to an abandoned plan to visit one such ski-in hut above Chama, New Mexico, many years ago. Still, I’m intrigued by these round self-supporting tents because they’re light on the land, exotic, nonconformist, and inherently transient: more grounded than a motor home, less site-bound than a cabin. (And yurts can be permanent, site-built structures, too.) Some people swear by circular homes, invoking the sacred nature of that shape, its lack of a beginning or end, its implied wholeness, its continuity with the spheres of sky and Earth and the metaphysical “round,” its metaphorical oneness. Having lived in a round house, I’ll confess that I can’t vouch for the spiritual benefits, but it did present considerable challenges for placing furniture.

Nonetheless, I’ll set aside that prejudice in consideration of this intriguing book by Becky Kemery. Yurts: Living in the Round has the exhaustive scope, the attention to detail, and the unflagging enthusiasm of an author utterly infatuated with her subject; her passion could prove viral. A reader might come away from this book thinking, “why doesn’t everyone live in yurts?” or “maybe I could open a yurt coffee shop in the mall parking lot.” OK, maybe that’s silly—or maybe not!—but yurts compel attention for a couple reasons. The first is their self-supporting design, which reminds me of my old Christmas tree stand: its legs were bound by a collar at the top that was held in place by the inward pressure of the legs under the tree’s weight. Yurts hold together by a similar static balance of forces.

In a yurt, balancing forces of compression and encircling tension create an equilibrium that keeps the walls up with remarkable stability. The roof comprises struts that meet in the grip of a center ring, which creates pressure toward the center and down, compressing the rafters middleward. The rafters set atop the lattice walls, the poles of which are held in stasis against this pressure by an encircling band, like a belt cinched around the top circumference. The downward and outward force of the roof is thus balanced by the grip of the band. The yurt stays up without any guy wires or bolsters. Historically, the two basic types of yurt are the Turkic and the Mongolian, named for the general region of Asia where they originated. To the layperson, the differences are minimal. They share the same basic design, looking like an outsized cupcake.

From this basic design perfected over the centuries by central Asian nomads, the yurt has flowered through technology along a few branches: as an elaborated tent, as a soft-skinned dwelling, and as a full-fledged, code-meeting, mortgageable home. Originally skinned in felted wool, yurts now wear canvas walls or rigid architectural fabric. Some even have wooden-framed walls with concrete foundations, their claim to yurt-hood resting on the compression ring and tension band that ties it all together.
Yurts: Living in the Round explores all these diverse articulations in apt text and often intriguing photos. As with many of these home or shelter books, half the fun here is peeking in windows and vicariously hanging out with cool people in interesting locations. As reported by author Kemery, for instance, the case studies and personal stories include not only the bodies of work compiled by leading yurt designer/builders in its American evolution, but also backyard yurts (teenage getaways), ski yurts, offices, and so on. Partly the tales demonstrate the mainstreaming of yurts, but they also lend a conversational air to these pages. The early chapters, which trace the early nomadic history of yurts, include both contemporary photos (Mongolia looking much as it probably did in Genghis Khan’s day) and well-selected archival images.

But Kemery’s book is far more than an academic or oral history of yurts. She wants to get you in one, today. To that end, Yurts: Living in the Round offers enough detailed information to qualify as a comprehensive guide. Kemery helps you decide what kind to buy, where to buy it, where to find a builder or get do-it-yourself plans, and how to combine yurts with their square cousins or with their own radial brethren. The book also includes extensive resources to get you started.

Following the Royal Road: A Guide to the Historic Camino Real de Tierra Adentro, by Hal Jackson, University of New Mexico Press, Albuquerque, 226 pages, 49 halftones, 60 maps, paperback, $19.95.
Two major overland routes transformed New Mexico before the railroad: the Santa Fe Trail and its predecessor in time, the Camino Real de Tierra Adentro, or the Royal Road connecting Mexico City to the capital of New Mexico, which was once San Juan and later became Santa Fe. American cultural bias has long favored the Santa Fe Trail, which sprang forth from Independence, Missouri. But really the Camino Real deserves at least as much attention. First blazed by Oñate and a small band of conquistadors, clerics, and settlers who reached San Juan in 1598—Coronado didn’t pass this way—this epic 1,500-mile pedestrian and equestrian road extended Spain’s reach into the New World across vast stretches of inhospitable desert, a string of Native American settlements, and one eventually border-defining river, the Rio Grande.

The modern mind probably can’t grasp the sense of isolation these earliest pioneers felt from their homeland, nor the sense of invasion the native residents endured before ousting them, temporarily, in the Pueblo Revolt of 1680. But then the Camino Real brought back the Spaniards permanently.

Given this rich, deep, and wide history, Hal Jackson’s book on the entire, binational Camino Real seems long overdue. Seen on a map—and, presumably through the windshield from the comfort and safety of the family car—this thread of highway underscores the geographical and cultural continuity between New Mexico and Old Mexico, a point easily lost these days. Separating New Mexico from Old is like peeling off New England from the United States, seen in this perspective—the two were once that integral. Maybe a long drive south, with Jackson’s guidebook in hand, might open American minds to the potential for cross-border cooperation.

Even if not, Following the Royal Road is rife with enough history and point-to-point travel detail to frame a total immersion experience in 400-plus years of human drama. Jackson has chunked the book into bite-sized pieces, with a staggering amount of detail, from driving directions to close-up maps to sidebars on silver mining. He must have worn out a set of Michelin tires driving the freeways, highways, gravel roads, and worse compiling all this firsthand information. The book includes an extensive bibliography for further reading, exhaustive index (people and place names, mostly), and even tips for traveling in Mexico, complete with specific hotel and restaurant recommendations in each major waypoint to Mexico City. It’s enough to make you trundle off to the Mini Cooper dealer on a late-April day, cut a deal on a convertible, and head to Española for Day 1 of a really, really long road trip south.

The Passive Solar House: The Complete Guide to Heating and Cooling Your Home, revised and expanded edition, by James Kachadorian, Chelsea Green Publishing, White River Junction, Vermont, hardback, 240 pages, includes CD-ROM with custom solar design software, $40.
James Kachadorian’s recently revised The Passive Solar House gives you everything you need to know to design a home heated primarily by our nearest star. This is no coffee-table, ogle-and-weep photo dream book. It’s part manifesto, part engineering primer.

A civil engineer and founder of Green Mountain Homes, which gained national recognition as the first provider of “kit” solar homes, Kachadorian explains the engineering and construction techniques like a genial professor who loves his subject. He covers the principles of solar heat, their consequences for home design, and the strategies for creating a successful solar residence. A layperson might scan through it lightly once just to see what’s here, but more likely you—or your contractor—will work through The Passive Solar House with a calculator in one hand and a pencil in the other, poised over a yellow legal pad, figuring out everything from the square footage of south glass to the size of your furnace. The appendix includes a comprehensive set of solar design worksheets, creating a step-by-step path to specifying the elements of construction related to implementing these solar principles described in the early chapters. The design software on the included CD-ROM helps automate this process.

Every aspect of solar heat gain and loss—windows, walls, roofs, you name it—is analyzed by Kachadorian in exquisite detail. The back of the book also harbors arcane charts and tables on solar intensity and heat gain at specified latitudes, the thermal properties of common building materials, the latitude, altitude, and “winter design temperature” of major U.S. and Canadian cities, the average degree days in those cities by the month, the mean percentage of possible sunshine—jeez, what a compilation! (And yes, Albuquerque ranks in the sunny top five!)

While most of the principles, ideas, and applications covered by Kachadorian will be familiar to anyone exposed to even the broad concepts of passive solar design, his “Solar Slab” foundation just might be his greatest and most unique contribution to the field. It is essentially a horizontally, passively heated radiator. The Solar Slab, for which he received a patent almost 30 years ago, uses the natural dynamics of heat flow—warm air rises, cold air sinks—to continuously draw sun-heated air through the house. The slab, itself the ground floor of the living area, is made of concrete blocks laid on their sides so all the holes align in rows. This forms continuous ducts across the width of the slab, with vents up to the living space at either end. These allow air to circulate from the house through the slab. In concert with passive solar features that collect the sun’s energy, the slab will store heat at room temperature (or slightly above), then continuously, nonmechanically circulate that warm air throughout the home.

Does it work? Kachadorian has designed and monitored a number of homes that prove it. I recently and for the first time visited an Albuquerque home built on the Solar Slab principle—we’ll report on that in a future issue. Kachadorian does concede that air quality should be monitored and the slab’s ductwork protected from obstructions or, gulp, infestations. On balance, though, the Solar Slab seems a brilliant system that moves passive solar design with thermal mass away from the less-attractive trombe walls to a stealthy, invisible, perhaps even more efficient alternative.

A CD-ROM included with this edition of The Passive Solar House includes design software and a “virtual tour of a sampling of solar homes designed by the author.” One photo series shows a home under construction using his Solar Slab, the pictures going a long way to help me visualize building such a home. And it makes me want to move to Vermont, where (I assume) the test-case home is located. And a beautiful home it is! Another photo tour—along with case studies in the book—shows a variety of homes built by readers of the first edition, a fitting testament to its hands-on value.

The design software on the CD-ROM at first feels a bit mysterious—maybe I should have read the directions first? But once I typed in various parameters according to the on-screen prompts, it generated a report listing those values and a prediction of the solar performance in BTUs. For my hypothetical house, it told me what percentage of the total heat load would be supplied by the sun. Thus I could run the program with different values for variables like the amount of south-facing glass, the degree of deviation from truly south-facing, the size of the slab, the value of insulating window shutters—it’s quite a list—and see how they each improve or worsen the home’s performance. For someone entering the design phase of a home, this CD-ROM tool alone is worth the price of the book.

But really, The Passive Solar House is worth much more than that. From the Solar Slab concept to the tours of pretty solar homes to the highly usable design worksheets and software, The Passive Solar House empowers its readers—its users—in such a reassuring, get-busy manner that you almost have to wonder, why aren’t all homes solar?