Energy Efficiency

The organizers will use accredited software tools to calculate a projected Home Energy Rating System (HERS) Index for each model home. The lower the projected HERS Index, the more energy efficient the home. The organizers will use the accredited software tools to develop an energy model of each model home. They will use data collected from construction documents, direct measurement activities, and performance verification activities to develop model inputs and calibrate model outputs. As the organizers learn more about the model homes to refine model inputs, the model will become progressively more accurate in predicting annual energy performance in the model home’s permanent location.

A projected HERS Index less than or equal to 40 earns all available points. A projected HERS Index greater than 40 and less than 60 earns reduced points, scaled linearly. A projected HERS Index greater than or equal to 60 earns no points.

• Renewable energy production is considered in the model and has the effect of reducing the projected HERS Index.
• The organizers may develop custom methods and tools for modeling innovative demand-side and supply-side energy systems and strategies that are not covered by the HERS standard.
• All supply-side and demand-side energy systems and strategies must comply with Chapter 1 of the OCSD23 Building Code. Systems and strategies that have significant benefits but do not currently comply with Chapter 2 of the OCSD23 Building Code may be approved for demonstration on the competition site and for consideration by the juries on case-by-case basis.
• When a team fails to provide information that is required to develop well-documented and validated model inputs, the organizers will make conservative assumptions that will tend to increase the projected HERS Index.
• Teams are encouraged to use software such as the Building Energy Optimization Tool (BEopt) to identify cost-optimal combinations of efficiency measures and renewable energy production. The effective use of tools like BEopt may be considered by juries.