High Performance Modular Building: Cost Effective Solutions for Design and Construction of a Sustainable Commercial Building

Abstract

This Case Study presents the design and construction of a new high performance building for the East Bay Municipal Utility District (EBMUD). The 5,600 square foot commercial building with offices, open cubicles, conference/meeting rooms, and locker/shower rooms serves 22 ranger staff that work in the Mokelumne River Watershed in the Sierra Nevada foothills approximately 30 miles northeast of Stockton, California. The designers created a unique building that included several sustainable and high performance features by employing a combination of “low technology” methods using design strategies from pre-modern historical practices with “high technology” analyses and controls. The sustainable features include water saving systems (rainwater collection, gray-water irrigation); low energy HVAC systems (radiant floors, natural ventilation, earth tubes, stack effect); and energy generation (PV, future wind turbine). The project goal was to achieve “net zero” annual energy use. Furthermore, the building was designed for steel-frame custom modular construction to minimize construction waste and provide a cost-effective building solution. This case study presents the design strategies employed in this project, the goals of minimizing water use and construction waste, the importance of reducing the energy demand, the benefits of non-conventional and low energy HVAC systems, and the potential for “net zero” energy use with a combination of power generation with PV and low-energy use features. The design strategies include project siting for optimum passive and active solar gain, using bioclimatic analysis for active and passive design strategies, high performance building envelopes to minimize thermal loss, floor slab mass for temperature moderation, and architectural features to reduce energy demands and to optimize day-lighting and minimize solar gain. Some of the unique sustainable features of the project include rainwater collection for HVAC hydronic systems, rainwater use for toilet flushing, a “night-sky-spray-chiller” for cooling water in lieu of a conventional chiller, earth tube preconditioning of ventilation air, 953 Structures Congress 2012 © ASCE 2012