Some dome types are more appealing from a construction viewpoint: less number of various elements makes planning, shop work and assembly less difficult. There can also be a more efficient use of raw materials. A simpler more efficient dome costs less. Some domes make better 1/2, 3/8 or 5/8 fullness. Other dome types are appealing for their unique symmetry and design variations.
Dome Homes and Dome Types
There are several ways to make dome homes. Our domes can be developed into homes starting with the hub-strut geodesic framework which provides a strong spherical triangle grid. The domes can be wood or metal- aluminum and steel. Connector Hubs should be aluminum or steel. Ideally for a dome home you would use a metal hub and wood strut system. 2 x 6 framing lumber will work very well.
Monolithic domes are ferro-cement type with a steel mesh and stucco/concrete cover to finish the roof. Our domes will work with this method as well as other roofing types.
One company uses an air bubble form to apply spray foam and spray concrete reinforced with REBAR. Another uses prefab lightweight cement triangles to make a sort of geodesic igloo. Others make “panelized domes” from hex and pent triangle sections built in the shop. These are tranported to a building site and assembled. The roof panels are already pre-attached. There is more flexibility of design and customization with hub-strut domes….
- A wood dome frame may be used as a support structure for creating a rebar frame work to which roofing may be applied, whether stucco, spray on concrete or other type. The wood dome can then be dismantled and reused many times. The frame can be covered with roof decking, plywood or OSB, and finished with a variety of roofing materials
- They may be small, simple inexpensive domes, or architecturally developed and refined for many residential and commercial use.
- Endless dome types and sizes can be created, including icosahedral, octahedral, elliptical domes and others.
Domes we make
1. Double Domes are made by using longer hubs and attaching 2 struts spaced apart instead of just one. In this way an insulating space is created between the outer dome and the inner dome. The inner dome could be spaced from 9 inches to 2 feet from the outer dome. An outer dome of 2 x 6s for example and inner dome of 2 x 4s could be used. There is plenty of room for wiring, ductwork, insulation, plumbing etc. between the inner and outer domes.
2. Subdivided domes are triangular divisions of the original dome design. Designated with “X” numbers according to the first, second and third division. The method is unique to domes built by us manufactured under authority of U.S. Patent. It is an innovative system that adds geodesically triangulated reinforcing structure to existing domes. The “Multi-Max” [MMX] hub system is used for attaching up to 12 struts arrayed strategically around a cylinder hub. Special features are that no compound [miter + bevel] cuts are required for the struts, and original triangle face planes of the dome are maintained so that there is no change in the amount of roofing material needed. Yet there is double or triple the amount of substructure under the roof making a stronger dome; with more framework for attaching the roof deck. The main dome may be 2 x 6 framing for example, and the “X” struts 2 x 4. Double domes may have one or both “X” types. The types may be different, or even variations of “X” type on a single dome.
3. Diamond Truss domes can be made similar to the double domes, but the inner and outer dome would be different. The inner dome ideally would be of less elements and larger triangles. These domes would have an insulating envelope between the inner and outer dome, with common vertices [hubs] at several locations. Either or both could be “X” types. Either also could be made of different strut sizes or strut material. The main advantage of this dome type is the simple way of adding pyramid-triangle space-frame truss strengthening to the dome. Also the interior dome would require much less material to cover than the outer dome, while creating an insulating envelope between the outside and inside.
4. Octet-Truss Space frames made spherical- Combines the concepts of the “X3” subdivision, double domes, and Diamond Truss domes. Fully divided truss domes in a omni-arrayed 3D pyramidal grid can be constructed. Cylinder hubs and typical strut material can be used throughout. These domes are ideal for covering large areas where a single dome would fail, or smaller domes requiring extra strength while using less expensive, lightweight materials used in construction.
5. Dome orientation. Domes are described as oriented edge zenith, face zenith or vertex zenith. In other words, you can have many orientaions of either face (triangle), strut or hub at the dome apex. Most often the hub at the top works best and gives a level or near level row of struts at the base of the dome.
6. Dome Classes. Describes orientation in relation to the underlying polyhedra, Class I, II, and III. At present we only use Class I and II Icosa and Octa based domes as well as Polyhedra Domes which are polyhedra divided and made geodesic, with pentagrams in the case of the Star Domes. See Introduction to Geodesic Principles
Construction for a permanent structure begins with planning. Consult with architects, engineers, local officials who govern areas for residential or commercial construction. An engineer can determine if a certain structure is workable for a particular purpose in a certain area to fit the climate, soil conditions etc. Architects and architectural designers create building plans with actual construction details that builders and contractors use for making the structure.
We can supply details of constructing the dome frame that engineers and architects can use for their work. Computer data and drawings supplied on diskette can be licensed to an individual for specific application to protect our proprietary information.
You may hire a local firm to build your dome home or other dome structure. You may also do most of it yourself if you have the abilities or have the time and willingness to learn. Professionals such as plumbers, electricians, roofers, cabinet makers, etc. may be hired. An unskilled person who is up for the challenge can build the dome frame, add the roof panels, windows, doors, flooring, insulation, vapor barrier, wall framing, drywall or paneling, paint, landscaping, etc. Our domes are ideal for do-it-yourself-ers who can work outside of areas governed by strict zoning, residential neighborhood building requirements. Long established builders such as Timberline, Oregon Dome, Natural Spaces, Geodesic Domes and Homes, American Ingenuity, Monolithic Domes etc. are good sources of information, home plans and quality buildings. Also check out the Dome Home discussion group at YAHOO GROUPS
The domes cost ultimately depends on hundreds of construction specifications. However domes may cost much less or much more per square foot than the average house. In other words there is the budget dome and the deluxe custom dome, and those in between. You would likely build according to your financial ability and how much you do yourself to save money.
It is possible to use our domes and working from premade stock building plans, construct your dome home, modified to your requirements. Write for copies of floor plans for dome size you are planning.
We are also available to travel to your building site to oversee the work acting as licensed builder or contractor, interfacing with inspectors, architect, etc. and scheduling work such as foundation, plumbing etc. Owner’s involvement may be as little or as much as they desire. We can be there for the entire construction period or minimal time to get the work started and progressing as scheduled.
Janet Snow writing on the DomeHome discussion list (join at www.domegroup.org) compares dome types (thanks Janet):
There are advantages and disadvantages to the different types of systems and different manufacturers. Just a few to think about:
Hub and Strut advantages/considerations:
- There is more of an option for you to work with a company (for expertise and instructions) and yet build your own kit. I don’t believe any of the panel system manufacturers will give you the instructions (measurements, etc.) to prefab your own panelized dome but that doesn’t mean you can’t do it on your own.
- The individual pieces are lighter and easier to work with eliminating the need for cranes or other specialized equipment.
- There are options for a super-insulated structure. (This should also be available with panelized systems but I haven’t seen any marketed that way.)
- Efficiency in framing materials — no doubling up on struts.
Panelized system advantages/considerations:
- More prefab is done on the ground.
- Have possibility to also do insulation on the ground before assembly.
- Dome erection can probably be accomplished faster especially if using a crane or other equipment (this may be a requirement).
- If you’re not a do-it-yourselfer, more of the work is completed by the manufacturer.
Concrete dome advantages/considerations:
- More options for free-form type structure.
- Can offer super-insulated structures.
- There are options for a panelized concrete dome (http://www.aidomes.com/) as well as “sprayed” concrete domes offering some of the advantages of a panelized system in a concrete dome.
- Roofing is less of an issue since the roofing material is integral to the dome. 5. Some feel that they are stronger but I’m not sure this is proven. (Having lived in earthquake country, what I’ve witnessed is that masonry – concrete structures tend to be more rigid and thus more susceptible to that type of damage than wood frame structures.)
Other considerations (some of these should be available no matter what type of dome you choose but they may influence your decision): What is the look that you like? What fits for your building site? Do you have concerns about insulation values? Do you have concerns about ventilation under the roof? What type of interior finish appeals to you? What kind of options do you want for lighting and ventilation (windows)?
Comment on panel dome construction:
Here is a page illustrating prefab dome panels. Panel Construction Also see Oregon Domes and others linked above.
A pre-made panel dome might be considered advantageous in some situations. Considerations:
- Eliminates connector hubs- Connector Kit cannot be used
- Panels will need to be delivered by motor freight or on a dedicated semi-trailer if a very large dome = larger package.
- More preparation time sawing, measuring and constructing panels, less time at the building site.
- Roof decking, insulation and interior panels can be pre installed.
- You will have many bevels and miters on the lumber (compound angles, left hand and right hand opposite), more difficult than simple miter angles on our hub-strut domes. (Some hub systems do not even require a miter)
- Large panels require 2-3 men to attach or use of a crane
As stated on the Thorton site describing a Timberline dome, a hub-strut system may be better suited for DIY dome home owner-builders. The Garden Dome system is the best for lowest cost smaller dome shelters, greenhouses etc. or larger domes for homes using the metal Connector Hubs.
Domes are used and enjoyed for many reasons. Above all they are strong structures that use material to enclose a volume of space more economically compared to traditional ‘square’ architecture. However the special appeal of domes is that a financially friendly, environmentally friendly, user friendly building can be used to work and live in. The warm openness of spacious living areas that create a comfortable dwelling space are what domes are all about. Most efficient use of natural resources and less expense used for heating and cooling the dome environment are special benefits that only dome dwellers enjoy.