The Carriage House

About 15 years ago I built the “Carriage House” using a prefabricated steel vault as a supporting structure for earthbags filled with scoria as insulation. It is a two story affair, with the lower one being a garage/shop and the upper one an office and storage space. I located a new 34′ X 16′ steel quonset building that was sold disassembled for $1900 delivered. I realized that if I raised it up 4 extra feet, I could build a loft in it, so that is what I did, using a double row of earthbags on either side to support it. There is potentially about 900 s.f. of usable floor area on two stories.

Each arched section is composed of five pieces, and there are 17 sections, so it entailed a lot of ladder work to bolt the thing together one piece at a time. Since the steel vault is completely covered with insulating earthbags, the building is very well insulated, and comfortable year-round. This concept could be converted to residential use, with the addition of kitchen and bathroom functions.

The end walls were created with wood framing and siding materials. Most of this wood was either recycled from nearby building projects (taken from the dumpster), or bought as remnants. The cedar lap siding actually represents four different styles, so the facade has a rather patchwork quality. The door and windows  were all recycled as well. The bags were initially covered with papercrete that adds to the insulation value, but then later the entire vault was plastered with durable stucco.

The first floor houses the garage, shop, and some storage functions. There is a separate entry door, as well as the garage door. If the building is oriented with the glass end wall facing south, significant solar gain can be attained (in this case it might be advantageous to provide a solar shade over the window to shade it during the summer. The staircase to the second floor is rather narrow (about 2 feet) because it must fit between the two-foot intervals of the joist/ties. The interior of the shell could be finished in a variety of ways, or even left with the steel showing, as I did with this workshop and office. Cloth material could be draped over it, sheetrock could be scored on one side to allow it to curve to the shape of the vault, or wood tongue and grooved siding could be installed, to name a few possible surfaces.

The second floor has 6′ 7″ of head room in the center, and this diminishes toward the sides. The significant counter space utilizes areas where standing room is not available. The front office area has plenty of natural light from the southern windows, which can also be opened to provide ventilation through to the northern window.

The cross section shows the hybrid nature of this design. In order to gain height, the steel shell is erected on top of an earthbag stem wall, and then the earthbags continue on up over the building. The double columns of the stem wall provides thermal mass on the inside and insulation on the outside. An insulated concrete pad is poured for the shop/garage floor. The second floor joists and tie beams are essential elements of the design, since they resist deformation of the vault from all of the weight on it.

As I recall the entire cost of the Carriage House came in around $5000, with me doing most of the labor, and a lot of scrounging for materials. You can read more details about this at and the basic plan is available at

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Multi-Unit Residential Building Plans

Owen Geiger is a prolific designer of simple and elegant housing solutions. Among his many designs are a number of multi-unit dwellings that could accommodate a range of multiple families or various living arrangements. I have recently compiled a page at that shows six of Owen’s designs that are for sale. I’ll post pictures of these below to give you an idea of how interestingly varied they are.

Double Unit Ecoresort


Six Pods


Rainwater Towers Apartments

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An Earthbag Privacy Wall

Wayne Talbot, a reader from South Africa, sent me these photos and description of an earthbag privacy wall that he just completed. I think that is very nicely done! Inspired by Owen’s earthbag building resources, I recently completed the construction of an earthbag boundary wall. 11m L x 2.5m high. Bags filled with building sand and 6% Portland cement.

Bags filled with building sand and 6% Portland cement.Chicken mesh attached to bags using roof nails.Initial plastering was done with a hand-held plastering ‘machine’ I got off eBay. Cost USD$140.00 delivered to S. Africa. Plaster is standard cement plaster. Top of wall waterproofed using ‘flash harry’ water proofing ‘paint’.

Thanks again to and Owen for the inspiration. This was just a ‘test’ project to get a feel for the technique. Next project will be an entire home (straight walls, contemporary house, Cape vernacular type architecture).

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The Glory of an Attached Greenhouse

Few things give me more pleasure than living among green plants, especially when they are edible. If you couple this with the possibility of helping to heat your house, you can readily see why people become attached to their attached greenhouses. I have built several of them, with different materials and designs, but the basic concepts are really pretty simple.

It is best to design an attached greenhouse into the original house plan, but it is often quite feasible to retrofit one onto an existing house. You need some space on the south side of the house wide enough to accommodate a growing bed and space for access. The area should not be obstructed by trees or other things that would limit the available sun light. It could have an outside entrance, but it doesn’t have to.

An essential element of a good growing space is plenty of translucent material to let in the natural light. This can be glass or plastic (such as Lexan). There are pros and cons of each. Glass is much more durable and clear, so you can see through it, but it is also more susceptible to fracture (a factor in choosing overhead material), and it does not pass on full-spectrum light. Plastics, on the other hand, can provide full-spectrum, diffused light (which most plants love) and they are more resilient to fracture, but they last only about 15 years at the most, and often you can’t see through them. The greenhouse shown in the photo employs some of both: the vertical portions are glass, and the roof section is Lexan. This works out well, since we can still see the view through the glass, but the plants get lots of diffused, full-spectrum light from above and we don’t have to worry about the possibility of falling glass.

My experience is that vertical glass alone is not sufficient to promote good plant growth; plants are happier with light from above. This can be accomplished either with overhead glazing, or with slanting glazing (see the photo of Paramananda’s greenhouse). Paramananda used glass and softens the light for the plants with a scrim material.

Any well designed solar greenhouse will have lots of thermal mass built into the design. This can be in the form of rocks or cement for the planter box itself, as well as the soil in the planter. Masonry floor materials can also contribute to this mass, and the wall materials can be chosen with this in mind. Some people include jugs or barrels of water in the greenhouse to store the heat. The idea is to store enough heat within the greenhouse, that you don’t have to provide auxiliary heat for the space.

Once you’ve captured all that heat in the greenhouse, you want to be able to keep it there over night, or during gray days. So portions of the structure that are not glazed and are exposed to the outside air should be well insulated. The glazing itself can also be insulated at night with thermal panels or curtains that are utilized at that time. We have both roll up curtains for the vertical glass, and insulating panels that fit into the overhead glazing. This pretty much assures that nothing will freeze, even in deep winter.

In order to utilize the extra heat that the greenhouse captures, you need a system of venting it into the rest of your house. This can be as simple as using operable doors or windows between the greenhouse and the other rooms, or providing high and low vents to accomplish the same thing. More elaborate methods involve heating ducts and fans to force the warm air where you want it.

Now comes the question of dealing with too much heat. The space might be delightful in the winter, but a wretched furnace in the summer if proper ventilation is not provided. There are several strategies for managing the temperatures within an attached greenhouse. One is to vent the extra heat back into the atmosphere directly. This is what I have done. Several of the windows open to let in fresh air, and most of the roof section actually is hinged and can be lifted up to let the hot air pass right back out. Then we have shades that we draw across behind the planting beds to keep the heat and light from being too intense in the portions of the house beyond there. Generally, you want cooler air to be let in down low (preferably facing the prevailing winds), while the hot air is vented out up high at the opposite end of the space, where it naturally rises.

Another strategy for venting the greenhouse is employed by Paramananda. She designed and built her house in 1991. As a student of Permaculture design, Paramananda wanted her house to embody many of its concepts. As she says, “Every element of the design should serve many functions.” Thus her greenhouse is not only a commercial growing space, but it also almost completely heats her house. With two stories and about 2200 square feet of space, this is quite a tall order! She accomplishes this feat by cleverly hiding tons of rocks in the four-foot crawl space under the first floor. A thermostat at the top of her two story greenhouse automatically controls a drum fan that will force hot air through the basement of rocks, to emerge via warm air vents throughout the house. The rocks both store the heat for use when the sun is not shining and moderate the fluctuations in temperature. If the whole system gets overheated, she can open a vent into the garage and spill some of the excess heat. Colder air is allowed to return into the greenhouse via vents at the floor level of the second story, and through a screen door between the greenhouse and the first floor. We sat perfectly comfortably in her greenhouse for quite a while, on a very warm sunny day; I could feel a refreshing breeze on my skin.

Paramananda’s greenhouse provides two other utilities (in keeping with her desire for multiple functions). Her clothes dryer vents directly into the space, thus providing needed humidity for the plants and allowing the heat to be recaptured by the circulating system. Also there is an enormous Russian stove in the space. These stoves are made with a huge amount of mass to store heat, and are amazingly efficient. Actually Paramananda says that this is one the few things she would change about her design, if she were to start again. In this climate where the weather fluctuates so rapidly, it is hard to know when to fire up her stove because it can have an effect some 24 hours after using it. She says a better choice for this climate would be a simple cast iron wood stove, that gives off heat much more immediately, and cools down more quickly. She typically only fires up the Russian stove about ten times a year.

While I was visiting Paramananda, I asked how she deals with the bane of all indoor gardeners: white flies and aphids. With white flies, she will vacuum up as many as possible, and then spray the affected plants with a mix of one teaspoon of liquid detergent in a pint of water. Also she makes little stakes that hold bright yellow cards (2″X4″) that are smeared with petroleum jelly. The white flies can’t resist landing on the yellow, and then they get stuck there. For aphids (and also white flies), her strategy is to spray them with “Bioneem”, made from the seeds of the Neem tree. This must be done every 7 days for five or six weeks, in order to interrupt their life cycle. Bioneem is available from Peaceful Valley Farm Supply (888-784-1722 or Another remedy for these pests that I recently read about is to spay the affected plants with a fine mist of very hot water (about 140 degrees F.) for several seconds.

There are many books with specific designs for attached solar greenhouses and there are two plans shown at I encourage you to consider adding one to your house plans, or to your existing house. It will pay for itself many times over with food, heat and pleasure.

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Novel Wind Turbine Concept

The O-Wind is made with vents in the exterior so that it can catch city crosswinds and spin accordingly. This means that city dwellers might be able to generate their own electricity with the typical swirling winds found in cities. You can read more about this interesting design at

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