Solar Pavilion I is an experimental structure that investigates ideas of self-organization in the building construction process. Rather than following a pre-defined plan, the structure is built by following localized assembly rules that are derived from structural and material properties. Given a set of parts and instructed to follow the prescribed rules, a group of workers will inevitably produce a stable system. This approach permits a large degree of re-configurability so that the form can easily adapt to different program and site constraints as it moves from one event to another.The structure of the pavilion is composed entirely of cardboard tubes of various length, thickness and diameter bolted together. These variables are governed by each tube’s position within the structure, with thicker tubes taking on larger structural roles than thinner ones. The overall form takes on the appearance of a structural diagram, with tree-like piers that are thick at the base and cantilever outward, getting successively thinner as they get farther from the supports. The stabilizing base of each pier is made of shorter tubes which are capped off for the additional function of seating. The tubes are all tilted slightly northward and the top ends are cut at a sharp angle in order to increase the amount of shade produced beneath. Originally conceived for a festival hosted by a non-profit environmental organization, Solar Pavilion I incorporates many sustainable building practices. All of the cardboard tubes used in the pavilion were either salvaged from carpet dealerships or donated by recycled material vendors. Waste was also minimized by allowing for every piece of cutoff tube to be used elsewhere in the structure. For the original CitySol festival, the Solar Pavilion functioned as a multi-use space where visitors could sit and relax in the shade, get information from various exhibits, and purchase drinks from a bar built into one end of the structure.