When it comes to building performance, too much of a good thing can become a bad thing. Humidification to provide medical patient comfort is a good thing. Frost and ice damage due to that same humidification is not so good.
When new building code requirements require high performance and innovation incentives, such as those found in green building rating systems, significant confusion and some building failure will ensue. This is the current situation that designers and contractors are facing in wall system air barrier design and performance. Overly complex and problematic exterior wall systems due to a market-driven design emphasis on energy savings, high performance, and innovation inevitably lead to increased risk and liability in all climates, and concern about mold and moisture damage in hot/humid climates.
Significant in 2012 was the issuance of the International Green Construction Code (IgCC). This provided a vehicle for codifying many elements of the U.S. Green Building Council (USGBC) Leadership in Energy & Environmental Design (LEED)® rating systems and ASHRAE standards that have been issued over the last decade. (Most of them have been released in just the last two years.)
The development of codes such as the IgCC are often based on collaboration through cooperating industry professional society sponsors. Despite the benefits of collaboration, high performance and innovation initiatives are often driven by code empirical laboratory analysis, which sometimes does not translate well to field applications. This codification is then pushed out to contractors, who unfortunately must then face the task of interpreting sometimes puzzling requirements that don’t always make sense or work in the field.