Example 4. Sustainable buildings, and local rules and policies, in San Diego.
About 40% of all energy in the US is consumed by residential and commercial buildings  . This potential for conservation and sustainability has been understood for many decades, as demonstrated in the development and availability of many technologies from new materials (lighter and better insulating, or requiring less energy in their manufacture), new construction techniques and processes (like prefab or modular kits), to renewable energy and smart grid applications. There is also no lack of economic feasibility, proven return on investment, or even consumer market demand for green buildings.
One important obstacle identified by researchers and commentators is when there’s a lack of city and local rulemaking to support innovative or cutting edge green building projects  . Ranging from zoning, permitting, engineering and construction standards, and other (usually legitimate) public safety ordinances, inflexible or not updated local and city laws may themselves prevent good sustainable building projects; or, hinder them with additional time and expense. This is also a straightforward example demonstrating the importance of engaging all three pillars.
Of course, a lot has changed in this area over the last 20 years, and many cities have not only addressed specific gaps by creating new zoning and permitting provisions, but many have successfully leveraged the deeper concept of embedding a more flexible and supportive governance framework into fundamental construction permitting and oversight processes. San Diego (California, US) is a good example. This starts with the city’s statement of purpose making building for sustainability a priority, and in order to be responsible on behalf of future generations. They created the Sustainable Building Expedite Program for a permit deviation process to balance support for innovations in green building with public safety standards  . They also created the “City of Villages” initiative  which engaged public stakeholders in a discussion process outlining and encouraging development best practices like mixed-use commercial and residential projects, car light community planning, and a variety of other sustainable development design priorities.