House 17
Click here to enlarge photos
House #
House Style
Size Ft2
Year Built
Cost/Ft2
17
Wood Framed Yurt
730 +ca. 100 for porch
2005
$55*
Architect/Designer
General Contractor
Sub-contractors (significant) & Type
Michael Villardi—Smiling Wood Yurts Owner None
Primary E-Design Factors
Significant E-Products Used
Results—Positive/Negative
Small house—less materials needed to construct

Did not disturb any native vegetation in construction

Solar Hot water (evacuated heat exchange system tube system)

Small on demand hot water for backup
PV array for well pump
Super efficient refrigerator
Use of recycled materials
Local wood that was milled on site
11.5 of 13Ac. parcel is jointly owned and will not be developed
Conserve refrigerator
Evacuated tube solar hot water system
Brevity of construction time, 4 months

Comfort with heat and cold seasons

* Plus owners labor
This house is an excellent example of a wood framed yurt. It's no different from any other stick framed house except for the shape, its 24-sides make it look and feel nearly circular. Cloth yurts are less satisfactory for a climate like the Methow's because they are difficult to insulate well, and can be too cold or too hot, but with insulation this house is comfortable. Yurts have several advantages in terms of sustainability:
• They do minimal damage to the site because they are often built on piers rather than on a concrete foundation. The owners stated that no native plants were damaged in building their house.
• They tend to be smaller than most conventional houses. Being smaller means less materials are used for construction. A smaller house also uses less energy for heating, lighting, etc. Also, a smaller house makes you think more sharply about the quantity of things you buy, and will need to store in the house. A point to consider though, is that yurts can be difficult to add on to, so think carefully about choosing one if you foresee the need for expansion (the owner said that Michael Villardi has designs that allow for easier expansion).
• Because of the circular shape, wind loading tends to be less than for houses with flat sides.
• Yurts can be built quickly. It took only four months to complete this yurt (which is typical), this compares to a year or more for most other styles of houses. Less energy is spent in the construction process.

A important feature in this house, that's often overlooked, is the use of solar hot water. Hot water heating accounts for a significant portion (ca. 20%) of the energy usage in a house. The house has an evacuated tube system (similar to Thermomax). Briefly, the system is composed a series of coated evacuated glass tubes. Each tube has a sealed copper pipe (the "heat-pipe") with a fin on it. The heat-pipe is filled with a small amount of a liquid which is heated by the sun until it boils and becomes a very hot vapor (like steam). The hot vapor than rises to the top of the heat-pipe which is surrounded by another larger pipe (the "heat-exchanger-pipe/manifold") that's filled with cold water and absorbs the heat from the heat-tube, cooling it and condensing the vapor back to a liquid—there is no exchange of liquid between the heat-pipe and heat-exchager-pipe. The cool liquid in the heat-pipe then flows down its wall for another heating cycle. This heated water in the heat-exchager-pipe then goes into an insulated holding tank, like a hot water heater tank. Cold water from the well is circulated through a copper coil, 120' long in this house system, that is inside the holding tank becoming the household hot water. While this may sound complicated, it is less so than you think. (Please note: the system in this house works slightly different than what was described above.) The home owner's system produces most of the hot water they need (except on very cloudy days). The heat exchange tank for the system was designed, and built by the owners, but manufactured ones are available. The house has a small on-demand hot water heater for the times when the tube system isn't adequate. When we visited on a hot summer day, the temperature of the evacuated tubes was 154°F, and the heat exchanger tank was139°F (115–120°F is normal for a conventional hot water tank).

Most of the framing lumber was milled by a miller in Twisp, (some of it was from the "Thirty Mile" fire). Some utility lumber and the shed building materials were owner-milled on site with trees from a fuels-reduction thinning across the river.
Each of the 24-panels which make up the exterior wall is 4'x8', because this is a standard size for sheet goods (plywood, etc.), construction waste is reduced. It has a low profile, and blends into the hills. There is an operable oculus at the peak of the roof. The house is insulated with blown in cellulose. The walls are 2x6, floor and ceiling is 2x8. Cellulose has several advantages over fiberglass, it has lower embedded energy (it's made from recycled news print and a small amount of boric acid), it fills voids better, resulting in a 20-40% better insulating quality than fiberglass batts, and it's less toxic to work with, and live with. A wood stove is used for heating, burning approximately 1.5 cords per year. The owners use Conserve™ high efficiency refrigerator.

The well pump is powered by a ca. 650w PV array (the pressure tank pump, and the house itself, is on the grid); the pump is an AC/DC model that can be switched to the grid (AC) when needed. The PV array is manually tracked during the day which increases its electric output (see also, House #7); it is adjusted for solar altitude manually a few times per year (see also, House # 12).

Many of the fixtures, doors, and other materials used were obtained from recyclers, like the RE Store in Seattle, or from ads on Craig's list, etc. The owners noted that Bear Creek Lumber has, at times, a section for wood that may be slightly damaged but quite usable, and is sold at a discounted price. They also stated the "Barter Fair" at Tonasket in October (part of the Okanogan Family Fair) is a potential source for items, and materials.

The house is built on 13 acres of land, divided into 4 individual parcels with each household owning one outright and sharing ownership of the fourth. The fourth piece can not be developed, but can be used for agricultural purposes. This is a good way to preserve larger pieces of land, which may be too expensive for a single buyer (but make sure that you check into zoning issues with Okanogan County before proceeding). The group has a legal document to address any issues that may arise from joint ownership. One interesting side benefit of group ownership is how the well system serves the three houses. One household uses one of the wells and the other well is shared by the other two households. (Note: Small group systems do not require common ownership of land. They can be setup in many situations if the system meets county regulations).

Owner's Advice:

Build a wood framed yurt, or remodel what you have if you can (because remodeling saves materials).