Energy Code Compliance Analysis

This section explains how xStar performs energy code compliance analysis based on IECC 2021 standards and how to interpret the results.

Prescriptive Energy Code Compliance Analysis

xStar automatically performs these calculations:

• Identifies line items that are part of the thermal envelope

• Calculates U-factors for each line item using REScheck’s methodology

• Determines the total UA (U-factor × area) for the building

Analysis Results

The system generates these results:

• Building total UA compared to maximum UA allowed by code

• UA breakdown by category and individual line item

• Compliance metric showing percentage above or below maximum UA requirement

Demonstration

The video below demonstrates the Total UA analysis functionality:

Current Limitations

Please be aware of these technical constraints:

• Framing with unfilled cavities is currently assigned R-0

• Below-grade assemblies are not yet implemented in the analysis