In 1982, Buckminster Fuller led a workshop exploring geodesics and other topics. From that workshop, the idea arose to build a biodome on John Denver’s Windstar estate in Old Snowmass, Colorado. In the summer of 1983, weeks before construction was scheduled to start, Bucky died of a heart-attack. In his spirit, a group of young architects and engineers including Bill Browning and John Katzenberger built the Windstar biodome.

The goal of the biodome project was to produce food locally year-round in a cold climate with solar energy. The dome was glazed with two layers of plastic film separated by an air space. Until the late eighties, the biodome was used to grow a variety of vegetables and fruit. The dome was separated into two levels, the lower level including a pond in which fish were raised, which doubled as a heat storage medium. An army of volunteers was involved to maintain the indoor (and outdoor) gardens. Today, only a structure and many stories are left.

When I arrived at Windstar three months ago and saw the dome, I knew immediately that I wanted to restore this legendary structure. Imagine re-building the last dome Buckminster Fuller designed! I soon learnt that I was not the only person excited about this prospect. Eden Vardy, founder of Aspen Tree, an NGO that aims to connect people to nature through agricultural training, had a similar idea. In fact, Eden and Aspen Tree’s co-director Paul, had erected another biodome close to Aspen in the fall of 2013. After Amory introduced us, it was evident we had to team up.

How to make this idea work? The first step was to develop design alternatives. Eden and I convened eight people—Greg Rucks, Dan Wetzel, Robert McIntosh, Garrett Fitzgerald and myself (all from Rocky Mountain Institute), Eden Vardy and Paul Huttenhower (both from Aspen Tree), and Michael Thompson, an architect with experience in designing grow houses—to participate a design charrette, a process to develop design alternatives.

The first goal of the charrette was to brainstorm design alternatives to glaze or skin the dome. We started the process outside, gathering all participants under the 5m-diameter dome (picture at top of this post), to be inspired by the dome’s history and understand the technical details of the current structure. After sharing stories about the biodome’s original state, we moved inside to start the charrette.

In the next hour, we generated many interesting ideas—building an opaque dome to use for mushroom-growth; using old parachutes as inside insulation; and building a fly-eye dome—and consequently selected four ideas to further develop. The group split into four pairs, each pair given the task to develop a list of materials and next steps per design alternative.

Four design alternatives were further developed:

1. Hard polycarbonate dome. The current structure is a “basket weave”-dome. As in a woven basket, the ribs alternatively pass concentric or eccentric of one another.  This means there is no flat plane to which to adjust all three sides of a triangle or five sides of a pentagon. Paul suggested a way to fix this by adding plywood to the joints, but the group questioned whether that was in line with Buckminster Fuller’s idea of ephemerilization—doing ever more with fewer pounds of material. Michael estimated that the material costs for the polycarbonate were ~$4,200 for a ~1200 square feet surface area (at $3.50/square foot), or double that if the parts were to be ordered pre-cut.

2. Double-inflated polyfilm dome. This was the design of the original dome (second picture in this post). In 1983, the intention was to perfectly seal the space between the plastic films and fill the space with a gas with a low heat transfer coefficient. The inserted gas between the films quickly leaked out, so an airpump was installed to inflate the “pillows”.  The benefit of this idea would be that few to no more material needs to be added to the structure of the dome. Michael estimated that the material cost for the double-inflated polyfilm would be $1,000 for the dome (at $0.75/square foot).

3. Extra external or internal structure. Greg and Robbie worked on the idea of adding an additional light structure around the outside of the dome, inspired by aluminum tent-poles, over which a permanent or temporary insulating material could be draped. The idea arose of a slinky-type external cover, made of aluminum or carbon fibre ribs and an insulating fabric, that can be pulled across the dome during the night. Michael suggested that an internal additional structure could be a better idea, given high snow loads in Aspen.

4. Fly-eye dome. Dan and Paul explored the idea of creating a fly-eye dome. This type of design would need much material compared to the three designs discussed above. Garrett accordingly asked what the primary goal of the fly-eye dome would be, to which the group agreed that the function was mostly aesthetical.

Reflecting on the charrette, it is most likely we will implement the double-inflated polyfilm dome, possibly with an additional internal structure as developed by Robbie and Greg. The benefits of this design are low material costs, identical appearance as the original, and quick installation.

The next critical steps for the projects are to raise funding for construction materials and to apply for a building permit. If you are interested to help during construction of the dome, please comment on this post.