This dome home is not just round, it goes around too! Well, it doesn't rotate but the shape is that of a torus AKA donut. Plus this donut has filling in the middle, particularly a living/dining room with doors to every other room. The home is a 3 bed / 2 bath design with huge master bath and gameroom plus a lab/office and spacious laudry and bath rooms. The bedrooms are comfortably large and the master closet is huge. Space is saved by having no hallways, a mediumish 150+ square foot kitchen, and clever use of dome squashing and elevation to create room.
Yes, the torus and central dome are squashed so that they have elliptical cross-section. This way the space sort of approximates that of a rectangular home. Take a look at the cross-section drawing in the above figure. There you will see a line representing a 6 foot tall person who is near the outer edge of the home. Notice that this person can walk all the way up to the edge of the wall and still not touch his/her head on the roof before the feet touch the wall. How is this possible? Three simple tricks: squashing and elevating the dome cross section, and using a torus shape.
Squashing a dome is necessary in many cases because getting about 2,000 square feet of usable space from a spherical dome on the first floor would leave you with a huge second and third floor to fill, and all the added cost - just too much house. Another alternative is to sink a huge dome so that only the top 60' by 20' section is used. This works but it leaves unusable space at the outer edges of the dome where the ceiling height is low. So squashing the dome is a good alternateive, however squashing alone does not do the job because the dome will still be 18 to 20 feet high at the center and there is wasted space at the edges. This was the case in the Elliptical dome home design.
So to acheive the desired low profile shape we must do squashing and something else, which in this case turns out to be utilizing the torus shape combined with elevating the dome. By going with a Torus, we keep the cicular/eliptical cross-section that makes an airform work, but we are working with a long tube of airfoil tinstead of one round piece. It just happens that this long tube is wrapped around in a circle. By having a long tube we can now make a shape that is only ten feet tall in the middle and 6 feet tall at the ends, approximating a typical 8 foot home. The final trick is elevating the dome above ground so that it curves back underneath somewhat. Combining these three techniques, the dome is kept low in profile with little unused space.
In the middle where the donut hole should be, I would like to have a great room that serves as dining/living room as well as the central hallway area - note that the home has no hallways so there needs to be some connecting space of some sort. So what do do? Why, build another dome of course! This one over the middle, the donut hole. In fact by playing with the shapes and sizes I was able to make the central dome have exactly the same contour as the cross-section of the outer torus, which promotes balance and harmony aesthetically.
Ah, but there are a few issues. One of them is the door openings and another is rain drainage. Since we have an elliptical cross-section to the torus, the inner wall of it extends about two feet into the room, all around. This would be fine if we didn't have about ten doors there. The doors require a door-shaped rectangular frame so we need a transition. In this case it seems like a recessed transition would work best.
Regarding the drainage, water will accumulate in the valleys of the roof unless we drain it somehow. I explored ways of making the center dome larger so that no valley esisted, and I ended up with huge, expensive, and hard-to-build rooflines. So the thing to do is to make do and live with the rain collection somehow. My answer is to run pipes from the low spot in the roof valleys to the outside of the dome, where gardens can use the moisture. Theyse can be vegetable gardens or landscaping, where you would choose water-loving plants for that area. I toyed around with something creative like an indoor waterfall or aquarium of some sort, but inviting water into the house almost never works in practical homes, and this home is primarily practical. It may be unconventional being round and all, but it is extremely practical in many ways. So the water gets piped away from the home.
From the inside out, the layers of an MDI monolithic home are: interior wall finish (stucco), reinforced concrete, foam insulation, airform, primer, and outer layer or layers, often stucco. Well, we have a bit of a concern here because Our torus bends down so that its outer surface becomes the inner sturface of the great room. This is a problem because the outside is the outside, not the inside. I'm sure that MDI will have wisdom and experience to know what to do with this situation, so I will leave it to the experts.
We certainly don't want the inner dome to rest on a layer of foam, unless the rebar will support such an arragement, and for cost reasons we probably want to have just a single airform. so what to do? I will send them an email to ask.
The dome must have roof cleats at the centor and at various radial points around the torus. These are for cleaning purposes. The dome must be cleaned once a year with brushes and clorox solution, so some provision must be made for the safety harnesses that the workers will wear when on the roof. Aha, nothing like thinking ahead. Additionally, some provision for actually getting up on the roof at all is necessary. This will be some sort of adjustable ladder system, though I do not know the exact kind at this time.