Commissioning is one of the most useful but least heralded strategies for green building. In a nutshell, it is the process of having all stakeholders (building owner, architect, engineers, future occupants, miscellaneous consultants) meet at the beginning of the project and decide on their goals for the building, then monitor how well each step of design and construction matches those goals--even after the building is built. Commissioning is also used for non-green buildings, but it is difficult to do a green building well without it.
Although the process of commissioning costs money because of the additional time spent by experts, companies who build a lot have found that it pays for itself. Disney has found that "construction cost savings are consistently more than commissioning costs", resulting in lower first-cost as well as better-controlled projects. (See the state of Florida's extensive summary describing Disney's process and its advantages.) This does not even include reduced lifetime energy costs, for which the Oregon Department of Energy has data on typical projects.
Commissioning is useful primarily because it:
- Facilitates whole-system design with buy-in from all parties involved. (Design elements or technologies slapped on later are nowhere near as effective.)
- Avoids contractor cost-cutting on materials or processes when it would jeopardize the building's performance.
- Sets performance goals, not just traditional specs--they determine the building's acceptable energy use, air quality, etc.
- Provides money for measuring success during the building's life. Most people don't realize how little we know about building performance, and measuring the variables specified by performance goals tests the effectiveness of different design strategies. It can also allow building owners to change things in the future if they are not working as intended.
All this is in addition to the benefits of a green building (reduced energy & water use, improved indoor air quality, reduced occupant turnover, etc.)