LEED CoreConcepts&Strategies_3rd edition - Page 030

Extracted Content

Figure 2.3. Induced Growth Over Time

Unchecked, positive feedback loops can create chaos in a system. For example, if urban temperatures rise too high, local populations may suffer or abandon the area. In nature, positive feedback loops are typically checked by stabilizing negative feedback loops, processes that shut down uncontrolled growth or other destabilizing forces. Stability and resilience in the system return as the feedback loops begin to control the change. To design sustainable systems, we must understand the positive and negative feedback loops already in existence or those we set in motion, to ensure systems remain stable and habitable over time.

Feedback loops—positive or negative—depend on flows of information. When information about the performance of the system is missing or blocked, the system cannot respond. For example, buildings without appropriate sensors and control systems cannot adjust to changing temperatures and maintain a comfortable

indoor environment. The information must be both collected and directed. Most buildings have thermostats to provide information and control temperature. However, there are many other parameters, measurable or quantifiable characteristics of a system, that are relevant to sustainability but do not get measured or reported in effective ways. For example, the amount of energy used by tenant-occupied buildings may be collected by an electricity or gas meter and reported to the utility company but not to the occupants, who therefore have no information about their energy consumption and no incentive to reduce it. If real-time information on energy use is delivered to them in a convenient way, they can use energy more efficiently. Some have called this the Prius effect, after the hybrid car that gives drivers information about fuel consumption so that they can drive in a fuel-efficient way. [16] Installing real-time energy meters where operators can act on the information is an example of connecting elements of a system so that they can interact and respond to each other more appropriately in the feedback loop.

16 Brand Neutral, The Prius Effect: Learning from Toyota (2007), brandneutral.com/documents/Prius_Effect.pdf.

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