timberline geodesic domes timberline geodesic domes
timberline geodesic domes
timberline geodesic domes timberline geodesic domes timberline geodesic domes timberline geodesic domes timberline geodesic domes
timberline geodesic domes
timberline geodesic domes timberline geodesic domes
 

 



Geodesic Structures

Pre-Planning

Architectural Options

Construction

Finishing

Geodesic Structures

Who invented the geodesic structure and for what purpose?

Buckminster Fuller, a philosopher, mathematician, engineer, historian and poet, invented the geodesic dome. One of Fuller's lifetime quests was to build designs to do more with fewer resources, foreseeing an eventual shortage in housing for humanity's growing population. He observed problems inherent in conventional construction techniques, as opposed to the ease of construction and indigenous strength of natural structures. Interested in creating a structure analogous to  nature's own designs, he started to experiment with spherical geometry in the late 1940's. He patented the geodesic dome in 1951. Today geodesic domes are recognized to be the most efficient building systems known.

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Why do geodesic structures save on building materials?

The primary factor affecting efficient use of materials and energy in a structure is its shape. Think of a soap bubble. A sphere represents the smallest amount of material surface area needed to enclose a given volume of space. A divided sphere becomes one of the most efficient shapes known to enclose a given floor area.

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Why do geodesic structures conserve energy for heating and cooling?

The answer again lies in the shape of the geodesic structure. The lower the total outside surface area (walls and ceilings) the greater the efficiency in energy use for heating and cooling.  A dome has approximately one-third less surface area to the outside than a box-style structure. The amount surface area exposed to the elements has a much greater impact on energy efficiency than insulation values. Additionally, heat loss from the foundation of a home is generally more dependent on perimeter length than floor area. A dome, having a smaller perimeter/square footage ratio than a box-style home, will lose less heat from the foundation.

Efficient airflow inside that dome adds to the energy savings further; the curved surface of a dome provides a natural circulation of internal air.  Outside the dome, the shape of the dome provides an aerodynamic effect; wind passes over the dome with less resistance. In comparison, a box-style structure provides a flat barrier to wind, creating positive wind pressure with air infiltration on one side, and suction, or negative wind pressure, with internal air exfiltration, on the opposite external surface.

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I have heard that geodesic structures are very strong, and can withstand earthquakes and severe storms such as tornadoes and hurricanes... is this true?

Geodesic structures have shown themselves to endure through severe storms and earthquakes, due to the strength of their design. Geodesic domes have been used successfully for Antarctica radar towers with up to 200mph winds for over 25 years. Geodesic structures also increase options for placement on rugged, steep terrains. 

Our domes use 2" x 6" struts to provide a very strong geodesic structure. Additionally, the Timberline Heavy Duty Connector System can be used with 2" x 8", 2" x 10", or 2" x 12" struts to increase strength, insulation capabilities, and snow and wind load capabilities.

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Why are geodesic structures so strong?

The nature of the spherical design provides strength because the stress is shared evenly by all the points of the structure. The dome shape allows environmental stress such as movement from an earthquake or wind or stress from snow loading to be evenly distributed throughout the structure. The geometry of the triangle offers additional strength to the dome shape.

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What other advantages do geodesic structures offer over conventional structures?

Interior advantages of the dome include greater freedom of floor plan design, cathedral ceilings, evenness of light, heat, and sound distribution. Domes display superior light characteristics as spherical shapes tend to amplify light while rectangular shapes tend to absorb light; in many cases it is actually brighter inside a dome without any interior lights turned on than it is outside. Acoustical advantages include more even sound distribution and approximately 30% less outside noise infiltration.

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Pre-Planning


How much does it cost to complete a dome?

As much as we would like to be able to give an exact figure, we can't.  There are too many variables in building a house, starting from the type of foundation (a full basement costs more than a concrete slab) to the type of finishes and fixtures.  What we have determined is that as a rule of thumb, domes cost from 10% to 15% less than a comparable box type house.  In addition, over 90% of our customers erect the dome shell themselves, which saves additional money.  We have had customers do all the work themselves and shop carefully for materials and bring in a completed dome for $60,000.  Others have spent several hundred thousand dollars to finish theirs.  Click here to download our latest newsletter with prices.

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What does Timberline provide?

We provide anything that is custom to the dome. This includes the dome shell kit (dome shell with plywood skin), dome extensions, triangular skylights, cupola kits and the specialized dome hardware such as the ledger hanger. We also provide blueprints for each specific design.

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What do I get locally?

You would purchase "off the shelf" material locally. This would include the roofing material, insulation, lumber for the interior, electrical, plumbing, doors, finishes and fixtures. Pretty much anything you can get at your local building supply store you would get locally. We have found that our customers can get these materials locally for less than they would pay us to bundle and ship. When we ship overseas we provide building materials necessary to complete the house.

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How much should I estimate for shipping costs?

Timberline uses common carriers to ship the dome to your building site. Depending on what you purchase, we use one of two shipping methods. 

For Strut Framing Kit or Complete Kit customers we will typically contract with a company for a complete truck. The flat rate is by the mile, not weight, thereby allowing you to ship as much as possible without additional shipping cost. In addition, the kit is loaded at our factory and stays on the same truck all the way to your building site. This reduces additional handling and the chance for damage. The rate for this can range from $1.05 to $1.55 per mile.

If you order a Connector Value Package or additional skylights, we would use a LTL (Less Than Truck Load) carrier. Here the rate is determined by weight as well as the distance to the job site.

We ship throughout the United States and world wide. Call us for an exact shipping quotation to your destination.

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Will I have problems with my building department?

Our floor plans are drawn by licensed California architects and licensed California Structural Engineers. Our plans meet all of the Standard and Uniform Building Codes. In most cases, our blueprints alone are enough to obtain your building permit. Occasionally, you will need to get the plans reviewed by an architect or engineer in your state. A quick call to your local building department will get you your requirements. We can provide plans that are stamped by a licensed engineer in each state.

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At what point should I order Timberline blueprints?

Once you've received our floor plan portfolio, and have decided on a model. Floor plans will be an aid in getting estimates for contracting services and determining project costs, getting appraisals for financial institutions, and going through the building permit process. The price of floor plans is credited to the price of your dome kit package at the time of order.  You may also print out our Timberline Building Flowchart to get a better understanding of the process.

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What are the differences between the different types of kits and packages you offer?

We offer floor plan package kits for any of our standard floor plans, ranging from small homes up to larger two dome models. For those wishing to create custom plans, we offer all the kits and components singularly as well.

For people wishing to save additional money by purchasing and cutting some of their own lumber locally, we offer two levels of kits, our Strut Framing Kits and our Connector Value Packages. These kits would be priced individually and then added to other desired components for someone wishing to follow one of our standard floor plans. These kits can of course also be used with custom plans.

Complete dome shell kits include everything you need to construct the complete dome shell: detailed assembly instructions; pre-cut, pre-drilled, color-coded 2" x 6" struts, studs, T-blocking, triangular plywood panels, beveled base plates, factory assembled riser walls (not needed for all models); heavy duty connectors; 3 sets of floor plans; nuts and bolts. Our Strut Framing Kits include everything in the complete kit except the triangular plywood panels. Full instructions for cutting your own panels are included.

Our Connector Value Packages include the complete heavy duty steel connector system; nuts and bolts for the connectors; pre-cut pre-drilled color coded 2" x  6" struts; detailed lumber cutting plans and assembly instructions, and samples of studs and T-blocking. Floor plans are not included.

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What are the price ranges for the different types of Timberline kits and packages?

Our standard floor plan package kits range from approximately $11,200 to $63,200; these packages include a complete dome shell kit, a skylight allowance, and any associated riser walls, extensions kits, ledgers and ledger hardware needed to complete the particular floor plan. This range covers plans for garages, and garage/workshops, smaller homes, mid-size homes, on up to our larger two-dome models.

3/8 sphere domes kits range from approximately $9,000 up to $18,000 for Complete Dome Kits; from $7,000 to $14,500 for Strut Framing Kits; and from $5,000 to $8,300 for Connector Value Package kits.

5/8 sphere domes kits range from approximately $12,600 up to $21,600 for Complete Dome Kits; from $9,900 to $19,000 for Strut Framing Kits; and from $5,900 to $10,200 for Connector Value Package kits.

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Can I visit a completed Timberline dome home?

We have a contact list of Timberline home owners who would be happy to show you their homes, included as part of our planning package.

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Architectural Options

What design advantages do Geodesic homes have?

The dome shell offers many exterior possibilities. Because of the distribution of stresses in the dome shell, up to 50% of the lowest ring of triangles can be removed. A Timberline kit offers five potential openings that can then be replaced by extensions to create specialized rooms. These openings, along with the upper portion of the dome shell being near a true round, make it possible to create ideal placements for solar and view advantage.

Interior advantages of the dome include greater freedom of floor plan design, cathedral ceilings, evenness of light, heat, and sound distribution.  In addition, geodesic owners note a less-definable quality of "well-being" inside their dome homes.

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What kind of foundations can be used with the dome kits?

The type of foundation best suited for your home is determined by the terrain of the land, the type of soil, and local building codes. The foundation of a dome differs only in shape from that of a conventional house. We offer standard foundation plans for concrete slab, crawl space or full basement.

If you have a unique foundation need, such as the side of a steep hill, or a dome that will have some conventional building extensions, our structural engineers and architects can design a foundation that will work for you.

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What are extension kits? How can they be used?

Additional space can be added to the dome's main floors by extending outward from the dome. These extensions can be placed along any of the dome's five natural openings. Extensions can be used to adjoin domes, build entryways, solariums, dining rooms, covered porches, and the like, and to expand existing rooms. Timberline carries extension kits ranging from 4 feet to 16 feet for all of our standard dome sizes.

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Can I join two domes or join a garage dome to a home? What is involved?

Two domes or a garage and a dome can be joined using a Timberline extension kit.

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What is a riser wall? What is its function?

Dome riser walls are an architectural feature unique to domes. When used, they raise the height of the dome to achieve more usable area in the dome's loft and to increase the potential height for entryways. Riser walls generally range from 3 feet to a maximum of  8 feet high.

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What is a cupola?

A cupola is an easy-to-add dome top option that can enhance the natural light and ventilation in your dome. It offers the possibility of a small third floor retreat, with a 360 degree lookout view. You can use a ladder, conventional stairs, or a spiral staircase to gain access to the cupola room.

To add a cupola, we fit threaded pipes into special threaded connectors, raising the cupola portion of the roof up to three feet. The pipes form a near vertical plane at the top of the dome, allowing for the use of conventional windows.

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What options do I have for windows?

There are many choices in window design and selection available for a dome home.

The first option is skylights. Individually or clustered, skylights maximize the usable space in any panel. Triangular skylights maintain the graceful shape and highlight the unique architectural structure of a dome.

Standard, conventional windows can be used in a dome when they are framed upright in the lower sections of a dome, or in a dormer. Conventional windows are generally less expensive than skylights.

A third option are conventional shaped windows that are specially designed for use in a sloping roof. These can be readily adapted for use in a dome home. We are happy to recommend sources of specialty windows to meet your individual needs.

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Tell me about Timberline skylight options.

Timberline offers a full line of top-quality skylights specifically designed for use in our domes. All of our skylights are double-glazed (two bubbles, with an airspace in between, sealed in a two-part aluminum frame) for energy efficiency, and are weather and impact resistant. We offer 11 different triangular skylights along with hexagon and pentagon skylights. The skylights can be either fixed or operable.

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Can I put skylights wherever I wish?

Skylights are the easiest window option to install, as they do not require special construction of dormers. Skylights can be placed on any panel of the dome. Take advantage of special views, or maximize the use of passive solar energy by following the path of the sun.

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Is there a limit to the amount of skylights I can use?

Timberline domes are engineered to accommodate an unlimited number of skylights. Check your local building requirements for requirements on how much of your structure can be glazed and if there are resulting insulation requirements.

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What is the difference between your 3/8 sphere domes and your 5/8 sphere domes?

These fractions refer to the sphere division of the dome. A 3/8 sphere dome is 3/8 of a full sphere of the dome's diameter and a 5/8 sphere dome uses 5/8 of a full sphere of the dome's diameter. Consequently, a 3/8 sphere dome has a lower profile than a 5/8 sphere dome of the same diameter. 

A 5/8 sphere dome easily accommodates  a second floor or loft. Using our patented Ledger Hanger system, the ledgers for a second floor or loft can be suspended from the horizontal plane of the sphere, with no need for additional load bearing walls or supports.

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Tell me about your ledger system for a second floor or loft.

Our patented Ledger Hanger Hardware system is fully engineered and patented for use in any 5/8 sphere Timberline dome. The Ledger Hanger Hardware mounts into the existing dome connectors to make the addition of a self-supporting second floor quick and easy. The design actually enhances the strength of the dome structure, as well as saving space and lending flexibility to the floor plan design.

Depending on the desired height of first floor ceilings, second floor joists can either sit on top of ledger beams, or they can be mounted flush by using joist hangers. Ledgers can be left exposed to take advantage of the beauty of the wood-grained beams.

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Can I have a loft or second floor in a 3/8 sphere dome?

Yes, you can have a loft or second floor in a 3/8 sphere dome, using load bearing walls.

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What is the smallest dome diameter you produce? What is the largest?

Our standard dome diameters are 24 ft., 30ft., 35 ft, 40 ft., and 45 ft., divided at either a 3/8 sphere or a 5/8 sphere. These sizes are used in our standard floor plans and are also available for use with custom floor plans.

On a case basis, we also have engineering to build as small as an 18ft diameter dome. For larger dome uses, we offer up to 100ft, in 3/8, 1/2 or 5/8 sphere divisions.

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I live in a cold climate, and I need a higher wind and snow load rating. Can I meet this requirement with a dome home?

Our standard dome shell uses 2" x 6" lumber. Our Timberline Heavy Duty Connector System can be used with 2" x 8", 2" x 10", or 2" x 12" lumber to increase snow and wind load capabilities. This also allows for more insulation and higher "R" values in extremely cold climates.

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Tell me about custom plans.

We work with a licensed architect who has spent many years designing domes.  If you are interested in custom plans, send in your sketches along with $25.00 and our architect will critique your ideas and give you a price to draw a set of plans. You will work directly with the architect on your plans. First, he will do a preliminary drawing from your sketches and his ideas. After you review that, the design will be further refined. When you agree on the design he will finish the set with foundation, framing, and roof plans. There will also be sections and elevations in addition to door and window schedules. The plans will be stamped by him with a California Architect stamp.

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Construction

How do I find a contractor who will work with geodesics?

Any licensed general contractor should be able to do the work.

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Can I put together the dome shell myself?

Yes. All wooden components of a Timberline Dome are pre-cut and pre-drilled to exacting specifications, and color-coded to make it easy for unskilled people to assemble them with precision and confidence.  The largest piece for a 45' diameter dome is a 10ft. long 2" x 6", which is easily handled by one person. Over 90% of our customers erect their Timberline dome shell themselves.

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How long will the dome shell take to put together?

Our largest standard dome (45 ft. diameter, 5/8 sphere) can be assembled by 3 people in 5 days.

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What equipment will I need?

The only tools you will need are socket wrenches, hammers, ladders, rolling scaffolding (desirable) and nail guns (desirable). Timberline Domes are completely free-standing during construction. No shoring up is needed. No special tools or expensive equipment, like cranes or forklifts, are necessary to assemble a Timberline Dome.

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Finishing

What kind of roofing does Timberline recommend?

Asphalt shingles are the most common roofing material as it is easy to work with and very attractive.  It comes in a variety of colors and textures and is affordable. Other options include wood shingles, metal shingles and spray on roofs.

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What kind of insulation is recommended?

Standard insulation material is used.  The most common choices are fiberglass or rigid foam. Timberline's 2" x 6" framing members allow for 5 1/2" of insulation, sufficient for most climatic conditions. Other options include spray-in expanding foam which is very effective.

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What about venting the insulation to prevent condensation?

Condensation can form in a cavity when there is air in that cavity. Moisture enters on the air and if there is an air space the air must be circulated to prevent moisture from building up. That is why attics are vented in box type houses. However, if the cavity is filled with a material that displaces the air, condensation is not a problem. That is why vertical walls on box type houses are not vented. They are filled with insulation.

The same applies to our domes. The walls are 2" x 6" and are filled with insulation. By using an expanding spray in foam insulation, it seals up the dome so well that no interior vapor barrier is needed.

If you would like to have a shell larger than 2" x 6" and leave an airspace, we offer venting details by notching the studs to allow air flow.

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I live in a cold climate, and I need a high 'R' rating. Can I meet this requirement with a dome?

The Timberline Heavy Duty Connector System can be used with 2" x 8", 2" x 10", or 2" x 12" lumber to allow for more insulation and higher "R" values in extremely cold climates.  This also increases snow and wind load capabilities.

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What kinds of interior finishing materials can I use?

You can use any standard interior finishing material such as drywall or wood paneling. Studs are 16" on center in each triangle, for easy drywall attachment.

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What kinds of heating, cooling, and air ventilation systems can I use?

Domes employ traditional heat and air conditioning, whether it be forced air, electric baseboard, or in-floor radiant heat. The plumbing, mechanical and electrical systems of a geodesic dome are no different than that of a conventional structure.

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