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The Dome-Yurt

A whole new building concept for a new era.

The new idea of Dome-Yurts or "Yome" or "Magic Mushroom" in its new combination gives a number of advantages over its wellknown single components. The disadvantages of both single buildings will often change into benefits in its combination.

The Dome-Yurt gives us twice as much living space and also saves us a lot of money through its unbeatable low-cost roof. The upper floor as a sleeping or resting space creates below much more utility space for the more active part of the day.

A Dom Yurt is easy to make from popular and traditional materials and also really fast to build up. As a result, this "low cost" building concept is not only interesting for low-incomers, but can also be used as refugee accommodation or emergency stations.

The Yurt in general: The pros and cons

Modern Yurts, without the elaborate felt isolation of their Mongolian predecessors, are not really well heatable in winter. Even when the walls are covered with thin plywood and the roof is upgraded with an inner tent, especially large yurts loses still far too much heat, in order to be heated reasonably effective and economical.

It is simply lacking in adequate insulation. The dome yurt, on the other hand, is below rather more a wooden house than a yurt, the stable wooden walls can be isolated from the outside very simply and effectively, which makes them easily heatable in the winter.

The modern yurt roof with its usual 30-degree roof slope is far too high and contains too much air, most of the heat stays at the top, down on the floor its much too cold.
During storms, the loud noises of the canvas are quickly quite annoying. The durability and tightness of the canvas is often much less than what we desire. A so-called pyjama (a very thin fabric above the main waterproof fabric) helps against too rapid destruction by the UV radiation of the sun. But it must be renewed itself all 4 to 5 years. But rarely all these expensive materials dont really stay waterproof after about 10 years.

Here the practical experience illustrates clearly that the comparatively high material costs for a fabric renovation after this time, have often caused that many have transformed their yurt later into a wooden house. In the dome-yurt all these yurt-roof problems are so different thanks to the dome as a roof.

The outer skin made out of Tippi fabric can also be helpfull for legalisation reasons. The durability of the fabric walls is often not the main problem (but quite different here in the fabric roofs of yurts). Complicated sewing work is not required for the walls, the fabric, or truck foil, is simply stretched around the building in one or two ways depending on the width of the fabric. But also an outer cover completely made out of wood would be quite easy and not even much more expensive.

Domes in general: The pros and cons

Geodesic domes are becoming increasingly popular. They are filigree but extremely stable constructions with a very special flair. The for our eyes confusing many triangles and the circular shape of the dome result in a monumental charisma, as we know it only from large churches. The ratio of material costs to usable space is unbeatable. But the tricky question is more: How do you cover a dome?

A domecover from canvas is always a very elaborate needlework. Therefore domes are mostly covered with plasticfoils. Therefore the cheapest option is used here in the dome-yurt: The greenhouse foil. Which can be very simply adapted to the round shape with folded strips in every section. It can be very well fixed and stretched by beeing rolled up with a wooden slat and screwed underneath the 2.floor.

A greenhouse foil also lasts about 4 to 7 years, but costs less than 10% of a Tippi canvas and does not need any sewing.

Domes are usually difficult to be heated, because they are usually not covered with a double layer. Such a greenhouse-Dome is warming up extremely in the sunlight, so in the summer we can only really use it at night. In winter it cools down too quickly, because it has no double layer and therfore no insulation at all.

Insulating the Dome-Yurt:

If we build our Dome-Yurt from wooden-boards the insulation is much easier to fix. Using these wooden-boards, instead of tubes or round bars, we create a wider gap (of eg. 10cm) for any kind of insulation materials. Triangular plywood-boards, already fitted with isolation, inserted into the wood triangles, can more easily be fixed. Any number of fields as needed can be covered or be left open like this. Allowing for an optimum and individual adjustment to each desired sunlight or insulation against th cold.

Ventilating the Dome-Yurt:

Also two opening windows for ventilation in the summer are much easier to be fixed into the wooden-boards triangles, as onto iron pipes or round wooden poles. With these windows and insulation, we improve the features that allow us to use the dome, even in times when it usually would be much too hot or cold inside.

Insulation and clima in the Dome-Yurt:

A good floor insulation and good insulated walls are here absolutely not a luxury. The outer skin can still be made of canvas, especially if it seems easier for permission reasons. The walls are often not the main problem in the durability, rather the fabric roofs. Complicated sewing omitted, the canvas (or truck foil) is simply stretched (depending on the fabric width, in one or two tracks) onto the building.

The lower part is completely made out of wood inside, which creates a good living environment, when the pores are not closed. Only untreated wood absorbs excess moisture and expels it back into the room again. Then often only a small gas stove is enough or heating. A stovepipe outlet often omitted.

A solid wood ceiling, which serves the upper dome as a floor, holds the heat down in the living area. And could even also be additionally insulated from below. Carpets and the mattresses in the dome serve automatically as noise and heat insulation.

The Dome-Yurt as a easy solar-heating-system:

A flap-door in the ceiling enables the entrance into the dome, which can be ideally used as a bedroom or as a storage space because of its smaller headroom. In the summer this flap-door can be closed during the day, keeping the heat upstairs.

In winter, this flap-door remains open during the day in order to get the heat down into the living space. In winter the sun warms up the whole dome sufficiently. The warm air can be send down easily through the flap-door and maybe an extra hole somewhere on the opposite side, with a small solar-electric fan.

The dome used as a bedroom creates a lot more work space below. If we only need to heat the lower dome-yurt part in winter with a woodstove or a gasstove, the heat of the day can be reused by opening the flap-door to preheat the beds before going to bed. The carpets and mattresses upstairs are automatically used for sound absorption and thermal insulation.

About Dome-Yurt legalisation problems:

From the outside, this combination looks more like a yurt, which is not usually classified as a permanent building and we therefore can more easily ship around the complicated approval procedures. It is a camouflaged wooden house because it is built entirely from wood inside. From helicopters, the building looks more like a greenhouse, which is often tolerated much easier than any other solid roof structures. In any case, the Dome-Yurt is a degradable lightweight building that does not even seal the ground because it has only 16 point foundations, which can be natural stones, cement stones or sidewalk slabs.

Done-Yurt costs and construction plans:

The construction costs are unbeatably low, it has the optimal potential as a super-cheap-multifuntion-building. All work processes can be greatly simplified by templates. The building can be easily created with common hand-machine-tools and a simple construction manual like here below. Not a lot of technical knowledge is required. This new building concept can create very fast and cheap very comfortable and variable living spaces . In these times of great refugee flows the domeyurt is in many aspects certainly the better alternative.

Dome-Yurt Contruction Plans:

The Dome-Yurt floor:

There is no need for a solid foundation. The buiding can rest on 16 well leveled points. The star-shaped floor with 15 corners is already adapted to the upper part of the Dome-Yurt, which also has 15 corners. At the end of the floor beams you can already screw the multiplexed wall bar connectors, which also hold the ring boards at the same time, which are needed for the alignment of the floor beams, giving us the exact shape. Accurate leveling of all beams saves a lot of additional customization work later on!
Especially for smaller diameters, the floor is reduced to 7½ corners for the tongue and groove, this means much less cutting work. The floor should be well insulated from below. To do this, simply fold a plastic foil with the distance between the insulation thickness from the side to the beams so that the insulation can be easily inserted. The ends of the foil are then simply foldeded over and fixed from above.

Then you start with the ground center. From the center, the individual segments are then braced with tongue and groove. Before starting with the next field, the edges are cut with a circular saw in each middle of the beams. Finally, the whole soil is polished smoothly and treated with linseed oil.

The Dome-Yurt walls:

To ensure that the fabric can not be destroyed, all wall beams need to be nicely rounded on the outer sides. The upper multiplex connectors can already be attached to all the wall beams. Then the wall beams are set and aligned at the top with a second board ring.
But only the ceiling beams give the wall beams their round shape and their final position. Only when all the beams stand and all are well aligned, we can put all the walls on and all windows and doors in. The wall boards would have to be exactly the same length if you did an exact preliminary work, which allow very fast work here.

Only when all the walls have been finished up to the top, we can build the second floor above. The interior walls give the building a lot of stability, which allows us a second floor. The walls can now be easily insulated from the outside, before the canvas (or truck foil) is stretched around it.

The 2.floor:

The ceiling of the yurt which is also the base of the dome section is slightly bigger than the yurt in order to create a little overhang of 10cm. This increases the durability of the Tippi fabric on the walls because most of the rainwater does not have to drain down the walls like in a classic yurt.

For the installation of the ceiling beams simply an auxiliary beam is screwed to the first beam which holds it on balance. The two round connector plates are already fastened to this first beam. All other ceiling beams are then only pushed in and pre-tacked with small screws.

Finally, the holes for the 8mm threaded screws are drilled and all screwed together tightly. The beam structure gets self-supporting through these two multiplex panels (Ø60cm). There is no need for a supporting beam in the center and the auxiliary beam can now be removed again. The top plate is let into the beams. Only the screw heads then peek out at the top. We should use here better locks or countersunk screws so that they do not make troubles at the upper floor construction.

The upper floor is then built like the lower floor. A small hatch (later with lid) serves to climb up into the upper floor. All overhangs of the tongue and groove are now sawn off flush with the ceiling beams. The whole 2.floor is now really stiffened by the layer of tongue and groove so that the now

closed floor is hardly moving even under high loads.

The dome as a roof:

The roof is often the largest cost factor in such kind of buildings. Here we save the most at the Dome-Yurt. The greenhouse foil costs only about 10% compared to all other roof covers. The upper part of the Dome-Yurt gives us double space but as a 3/8 Dome version it is kept as low as possible, so that the building overall is not too high. But already at 4.70m diameter we get in the middle of the dome part already 2m standing height. If this upper part is ideally used as a bedroom, the standing height here does not necessarily play an all-important role. If nessesary we can upgrade to a 5/8 Dome version, which would gives us much more hight in the upper part.

The Dome Struts:

If you use tongue-and-groove boards, both the grooves and springs were sawn off with a circular saw, then all four edges were rounded with an upper cutter.
The 120 strut struts:

30x A: 0,354040755 x diameter

55x B: 0,409824871 x diameter

80x C: 0,418822637 x diameter

are sawn to the correct length at the correct angle (A = 10 ° and B + C = 12 °).

They do not bump into one another in the middle, but hang in the air so that a center block of 4cm would fit in. This saves an expensive bevel of all tips. The circular center block, which was still planned at the beginning, has proved to be not needed in the end since the cutt outs on the struts together with the round connectors also ensure the correct spacing and are sufficiently stable. With a simple gauge made of metal sheet, these cutt outs for the connector plates are indicated. The gauge adjusts at the preselected angle so that it can be used for all struts (A+B+C). The cutt outs are then sawn with a jigsaw.

The connector plates:

Two round multiplex discs (46x 20cm and 46x 14cm), with rounded edges on one side, will connect all the struts to each other. They give it a truly amazing stability. There are (40x) 6 and (6x) 5-way connections. The screws (e.g. 4x40mm) are positioned in such a way that they do not penetrate tightly into the wood from the two sides because they would otherwise split it.

Each dome strut is so held in position with a total of 6 screws. The forces are distributed very uniformly in the dome and always only on pressure, so that the cut outs (15mm outside and 9mm inside) can ensure sufficient stability.

The 92 connector plates are most simply made from pre-sawed squares with 20.1cm (and 14.1cm) edge lengths. Determine the center with a circle and pre-grind with a nail.
 

Then screw it to the jigsaw, to which a suitable adapter for radius sawing has been atached. One can simply use the other side of the stop of the jigsaw. The center point must be exactly at the height of the saw blade, otherwise the saw blade will cut off either outwards or inwards. The circular sawing process is so simple and super-precise to the exact diameter (20cm and 14cm).

A small radius is milled with a top mill so that the greenhouse-foil is not be damaged later. The connections are very stable and very easy to mount or dismount.

The isolation triangles:

There are only two different triangles, each of which has a "B" as the basic length, and either form an equilateral triangle with two "A" s or two "C" s. It is best to first create a template in 1:10 scale to find the best possible use of the entire multiplex panels. The first triangle plate can the be used as a template for sawing the others. Better put together a set of a 5-corner and a 6-corner circle to see if the triangles of the inner panel fit well. In order to calculate the edge lengths of these triangles, we can calculate the lengths with the Domcalculator when we enter the radius that lies on the inside of the panels.

The dome structure:

The assembly is started from below with five 5-corner and some half 6-corner segments. Already at one third of the first ring the structure stands by itself, so that we can build comfortably. Thus, the second and third ring are also expanded to the top. The crowning finish is then the top 5-corner.

The wooden dome is so sturdy that we can even hang a hammock or an acrobatic vertical scarf. For this, simply drill 8mm holes through the center of the two connector plates and use appropriate lock screws and ring nuts to create practical eyelets to attach such things. Also an LED lighting can be very aesthetically accommodated in the connector plates.
The windows are fitted later into the desired triangle, but we should already saw the connector plates accordingly before putting the greeenhouse foil on. The greenhouse foil can only be installed when all these works have been completed and will be secured with ledges under the second floor with 3 screws each. In each segment, except the ones for the windows, the foil is folded a little way to fit the round shape as best as possible.

The windows:

Most ideally, the windows in the dome are installed in the triangles, which have a B-strut as the top. The position is ideally as far down as possible, because they are not quite so inclined and so easier to get waterproove. First, the outer connector plates (the simplest before the greenhouse foil is stretched) are sawed in such a way that the full triangle is open. Then we build with the measures of this triangle a conical frame triangle (also with 12 ° inclination) which extends about 4cm. Two other interlocked and bolted frames (with two hinges on the top) serve as window flaps, which are simply covered with greenhouse foil. In doing so, guide the tarp on the top of the hinges all the way to the rear. Because there will be most of the water later.

Only when everything is finished the window is pressed into the prepared triangle from the outside and held from inside with a total of 9 screws. Finally, all connecting edges must be finished with a suitable sealant. A broomstick serves to set up the windows. A cord pulls against it, so that the wind can not open the window even further. Two differently long poles (completely up and only slightly tilted) have proved very successful. The cord is held with a knot and in a notch on an extra small board.

Dom-Yurts Construction plan (Example with 4,50m):
The Floor
Floor: 15 Corner,
Diameter: 450cm,
Radius to the corners: 225cm,
Radius edge to center: 220cm
Segment angle: 24 °,
Edge length outside: 93.56cm
At 7½ corner maximum plank width per double segment: 183cm
Beam center plate: 20cm (multiplex 15mm),
Beam length: 215cm x15x5cm (15x)
Tongue and Groove: 15.4m² (about 17m² with waste)

The Walls
Wall beams: 207cm x7.2x5cm (15x)
Internal walls: 90.6cm
Area inbetween: 85.5cm
Tongue and Groove: 26m² (about 30m² with 2m or 3m boards)
1 door (83cm x 200cm), 3 windows (80cm x 100cm)

Second Floor:

Dom floor: 15corner
Diameter: 470cm
Radius to the corners: 235cm
Radius edge to center: 230cm
Segment angle: 24 °
Edge length outside: 97.7cm
At 7½ corner maximum planks width per double segment: 191.16cm
Beam center: 60cm (multiplex 15mm)
Beam length: 220cm x 10x5cm (15x)
Tongue and Groove: 16,85m² (about 18,5m² with waste)

Dome 
3/8-Dom in 3 frequent execution 120 struts,
46 connector points 
(92 in total with diameter: 20cm and 14cm)
Approx. 2x multiplex boards 15mm for all wall and dome connectors
4-way connectors (bottom): 15,

5-connectors: 6,

6-connectors: 25 (4-way can be the same as 6-way)
Diameter: 470cm
Radius: 235cm
Building height: Dome 195cm, Yurt 232cm,
Total height: 427cm,
Strut lengths at 4cm core:
A (30x) 79.14cm (angle = 10 °)
B (40x) 92.21cm (angle = 12 °)
C (50x) 94.31cm (angle = 12 °)
Strut width: 10cm x 2cm

Insulation:

14x 205cm x 85cm = 24.4sqm -3 windows (-2.4sqm)
22m² insulating material = 75 €
60x triangle with styrofoam 2 per plate ca 2,45 € = 73,50 €
75x triangles overall, of which about 60x triangles covered, rest open for window and light.
Edge length Dome inside: A = 79.7cm / W = 92.2cm / C = 94.2cm
We get out 6 triangles per 8mm multiplex plate, makes 10 plates with 12 € = 120 €TOTAL COSTS (Example)
Tongue and Groove Total: 83.5m² x 8.50 € / m² = 710 €
Beams Total for example from: 23x 450cm x15x5cm = 0,77625m³ = 270 €
2x multiplex plates = 60 €
1 door with glass = 145 €
3 windows with glass = 345 €
Plastic foil: 7x7m, 49m² x0.80 / m² = 40 €
Fabric or truck tarp: 2.20m x 13.50m ca: 29.7m² x 10 € / m² = 300 €
Insulation: floor: 70 €, walls 75 €, triangles 73,50 + 120 € multiplex = 269 €
Screws: Dom: 1100, walls: 820, floors 1200 = 3120 x 2cent = 63 €

Total material cost: 2272 €
Estimated working time: 245 hrs. e.g. by 12.50 € = 3062 €
Total price excluding transport: 5334 €