Modeling Homes Without Installed Appliances

Modeling Homes Without Installed Appliances

In Ekotrope, you can indicate whether a specific appliance (such as a dishwasher, clothes washer, or clothes dryer) is present in the home by checking or unchecking the box next to the appliance's name.

Impact on HERS

According to ANSI 301 standards, a home cannot receive an energy efficiency credit simply for lacking an appliance. When you uncheck an appliance box, Ekotrope automatically assumes the presence of an appliance matching the HERS Reference Home default specifications for both the Rated Home and the Reference Home. Because the appliance specifications match exactly in both models, the energy use mathematically "cancels out," ensuring the home neither gains nor loses credit on its HERS Index. 

Impact on ENERGY STAR

The status of this checkbox directly affects the ENERGY STAR Target Score. For programs like ENERGY STAR, the target reference home changes based on whether the appliance is installed:

• Checked: The Target Home is modeled using a "Standard 2018-Present" appliance, which is generally more efficient.
• Unchecked: The Target Home is modeled using the less efficient HERS Reference default.

Because of this rule, unchecking the box can cause a slight shift (often an increase) in the ENERGY STAR Target ERI since the reference home is now being modeled with less efficient equipment.

Ekotrope's Recommended Workflow

Ekotrope's official guidance for using this input is as follows:

• When the appliance is NOT installed at the time of Final Inspection: Uncheck the box in Ekotrope. This applies even if hookups are present but no machine is installed.
• When the appliance IS installed: Check the box and complete all necessary inputs based exactly on the equipment's EnergyGuide label. 

Note: While checking the box and manually selecting the "HERS Reference" default has the exact same mathematical effect on the HERS Index calculation, Ekotrope recommends simply unchecking the box when the appliance is missing to ensure utility programs and above-code programs (like ENERGY STAR) correctly recognize the appliance as not installed.