The last two decades have seen a tremendous increase in the stringency of California’s building energy efficiency code, Title 24 Part 6. Along with these changes, the complexity of the code has increased dramatically, as different design options for building envelope, heating, ventilating and air conditioning (HVAC) and lighting systems have become available under prescriptive compliance paths. Meanwhile, the performance compliance approach, often perceived as a way to trade off efficiency measures or efficiency levels of different components or building systems, is reaching its natural asymptote: most design best practices, such as daylighting controls, demand-based reset of chilled water supply temperature, and cool roofs, are already required by code. There is little left to trade off. Without major advances in technology, the cost effectiveness criteria that are prerequisites to updating California’s Building Energy Efficiency Standards become increasingly difficult to meet over time.
All of these factors highlight the need for an energy code that is a true indicator of whole building performance. Yet the question remains: how can an efficiency level be mandated for a broad class of buildings with different design requirements, while maintaining fairness? This paper looks upon advances with both the energy code and compliance tools to illustrate potential paths forward, which both incentivize high performance design, while maintaining a reasonable standard for compliance.
In summary, while policymakers are geared for the long journey toward zero net energy commercial buildings as code, there are first a few hurdles to cross. Consider these recommendations to transform energy efficiency codes to promote high-performance designs:
- Provide industry with clear, consistent explanations of the scope and the intent of prescriptive and performance codes.
- Revamp the performance code, so that it can apply to both code compliance and green building programs.
- Develop a set of prescriptive packages that provide clear direction to the building community on requirements and enable designers to more easily weigh the impacts of their design choices.