Code Compliance
Energy Code Compliance Approaches
There are multiple ways to demonstrate that a commercial or residential project meets the requirements of the energy code that a state or jurisdiction has adopted. Design teams can choose from two broad compliance path categories: prescriptive or performance.17 Each has its own set of benefits and drawbacks. In addition to providing information about both, this section will seek to demonstrate that the performance path is the preferable option for a growing proportion of projects in terms of minimizing energy costs and carbon emissions.
Performance Path
The performance path uses energy modeling software to calculate annual energy consumption and costs. Instead of setting minimum standards for individual building components, the goal of the performance path is a building with an EUI equivalent to (or better than) one built to the prescriptive code. Say for example that an office building shows compliance with the applicable energy code using the prescriptive path and is found to have an EUI of 82. A design team using the performance path would then aim for a building with an EUI or 82 or less – but the allocation of resources to reach this target would be at their discretion. The theoretical base case building is known as the standard reference design; its performance-based doppelganger is called the proposed design. Energy codes can inform design strategies as much as the constraints imposed by other requirements – aesthetic, programmatic, economic, or others – can influence how the team works towards code compliance. This freedom makes the performance path especially appealing for firms that work with unique or unusual building forms. In BCAP’s survey of design professionals, 47% of respondents chose flexibility in design strategies as the most compelling reason for selecting the performance path.
The performance path conceptualizes the building as a single complex organism rather than as a kit of parts. In the same way, the performance-based design process is transformed from a series of discrete points to a tightly interwoven system. Just as the quality of windows might have ramifications on solar heat gain – and therefore on the sizing of HVAC equipment – the caliber of effort given to early energy considerations will impact a number of other design stages, from mechanical engineering to actual construction.
For large and complicated commercial buildings, as well as those with innovative energy efficiency features, the performance path is without question the better option. It is nearly impossible to make an informed choice about design strategies based only on rules of thumb. (One architect and participant in the AIA 2030 commitment goes so far as to compare working without an energy model to driving a car while blindfolded.23 ) Embedding energy modeling into every phase of design empowers professionals to become invested in long-term energy management, beginning with code compliance. Energy therefore takes its crucial place among the other numerous factors that determine the final form and functionality of a building. We can think of the performance path as promoting energy-conscious early design.
Summary of Performance Path Advantages
- Allows design professionals to prioritize energy-saving measures based on which strategies will be the most cost-effective
- Facilitates compliance with increasingly stringent building energy codes
- Frees creativity and innovation from the limitations of prescriptive component requirements
- Gives clients and stakeholders an estimate of a building’s operational costs
- Familiarizes design professionals with a workflow that can also be used for beyond-code targets (e.g. LEED certification, utility incentives) and the eventual goal of net zero energy (NZE) buildings