Why bother making custom entrances for your dome?

Geodesic domes are great for Burning Man. Their construction from triangular shaped elements makes them beautiful and incredibly strong. However, if you intend to use your dome as a shelter or shade structure for your camp, you will need to get in and out of the dome often. The triangular shape does not make a good or convenient entryway, unless the triangles are sufficiently large that someone could easily walk inside them (that requires struts made from a single 10 foot piece of EMT conduit .) If you have designed your dome making two struts per 10' length of EMT conduit, you will want to think about providing some sort of entrance.

A common solution frequently seen on the playa is the simplest approach, made by removing a horizontal strut around waist level, resulting in a kite-shaped entry, looking something like this
simplest door for 3V simplest door for a 2V
"default" 3V entry "default" 2V entry

While this kind of entry is easy to implement, it fails on two important levels. 

First, from a portal perspective, it is awkward. Humans are not kite-shaped, and the narrow part at the bottom creates, if you will pardon the expression, a severe tripping hazard. Getting in or out of the dome requires paying careful attention lest one's feet become entangled, resulting in a not-so-spectacular face plant onto the playa!

Second, removing the horizontal strut weakens the dome. While this is probably not a significant worry unless you remove many struts or have multiple entrances, I am an engineer and it just offends my sensibilities to weaken such a beautiful and strong structure.

When we first built our domes in 2002, I asked around to see if there were any better extant solutions for entryways.  Not finding any, I took the opportunity to play around with my 3-D model in a CAD program, trying various designs and shapes.  Starting with nothing, I kept these requirements in mind as I converged on my solution:
  1. must be free of tripping hazards on the bottom
  2. must be wide enough to allow unencumbered passage at waist, shoulder, and head levels
  3. must be tall enough to allow (most) people to pass without ducking
  4. must not significantly weaken the strength or rigidity of the dome structure
  5. must be aesthetically pleasing to look at
  6. must be as simple as possible, considering the above limitations
This is what I came up with:
Disco's custom 3V door design small custom
(click image for details and instructions for the 3V doorway) (click image for details and instructions for the 2V doorway)

Disclaimer:  These are my entrance designs, and while they have worked very well for our camp, I make no claims that these are the best possible ones that can be designed or built, ever.  I settled on these shapes to fit  my above criteria; other (i.e. much smarter) engineers may have even better designs.  Feel free to copy my work if you like, or modify the designs as you see fit.  I provide this information free of charge to all who are interested, as a way to give back to the dome-building community for the help I received in 2002.  I provide no warranties, use all information at your own risk.  Comments and questions can be sent to discodav at discodav.com.