Daniel Overbey is the Director of Sustainability for Browning Day Mullins Dierdorf Architects in Indianapolis. His practice and writing focuses on high-performance building design and construction, environmental systems research, LEED-related services, and energy modeling. He has been published in High Performance Buildings,EcoBuilding Pulse, Environmental Design + Construction, as well as other trade publications and media outlets. Overbey is also a building science educator at Ball State University's College of Architecture and Planning and the Boston Architectural College's Sustainable Design Institute.
The ways in which liquid and vapor move through our building envelopes are complex, and even today not completely understood; but the fact that lots of water can (and does) move through porous building materials is a phenomenon that rules over so much of the way we build.
Design teams would be wise to provide natural ventilation strategies that can function with a variety of wind directions in order to provide effective passive cooling for the greatest amount of time.
The building envelope must face a number of damage functions: bulk and capillary water, air-born water, vapor, radiation (ultraviolet degradation), pests, and people.