University of Maine Orono - we designed and built the Harold Alfond Hockey arena in 1975 to seat 3,000 spectators. Thereafter in 1992 we designed an addition to increase the seating to approximately 6,000 for hockey and basketball. The design of the structure was thin shell and it was designed to carry the heavy snow and ice of the region. The mechanical system, of particular importance in a hockey arena, consisted of an engine generator which provided power for the building and the waste heat of which was used for domestic hot water and some heating. The operational cost of this system was a third of conventional rinks of comparable size.