USER GUIDE

1. 1. Select the Code Pathway: Prescriptive or Performance
      • • The Prescriptive code pathway should be selected for buildings complying with Standard 90.1-2016 or Standard 90.1-2019, or their equivalents (e.g. 2021 IECC), and their associated requirements, including:
          • Building Envelope;
          • Heating, Ventilation, and Air Conditioning;
          • Service Water Heating;
          • Power;
          • Lighting; and
          • Other Equipment.
        • The Performance code pathway should be selected for buildings complying with Standard 90.1-2016 or Standard 90.1-2019 (Appendix G). A whole building energy model must be completed prior to selecting this pathway as the resulting estimated energy consumption will be required.
   2. If the Prescriptive Code Pathway is selected, select the Compliance Standard: Zero Code / 2021 IECC Appendix or Zero Code 2.0.
      • • Zero Code / 2021 IECC Appendix should be selected for compliance with Standard 90.1-2016 or the 2021 IECC Appendix CC: Zero Energy Commercial Building Provisions.
        • Zero Code 2.0 should be selected for compliance with Standard 90.1-2019.
   3. Enter the building’s geographical information, including the Country, State/Province (where appropriate), City, and Postal Code (where appropriate).
      • • Note: The building’s location is used to determine its climate zone.
   4. Enter the Number of Stories in the building.
      • • Note: The building’s Number of Stories is used in conjunction with the Gross Floor Area and a perimeter reduction factor to determine the default Estimated Area for Collectors for the On-Site Photovoltaic (PV) System(s).
   5. Select the building Use Type(s) from the drop-down menu. A new box with details about each use type will appear below.
   6. Add additional Use Types by selecting options under the Add Another Use drop-down menu.
      • • If the building contains only one primary use type, this step may be skipped.
        • Note: The total area of all space uses will be used as the total gross floor area of the building.
        • Note: Support spaces (e.g. corridors, storage, etc.) should not be entered separately. Their square footage is included within the associated Use Type; (e.g. office corridor is considered part of the overall office floor area).
   7. Within each Use Type, enter the Gross Floor Area and associated Units.

Modeled Annual Energy Consumption will appear if the Performance Code Pathway is selected. Inputs for this selection are derived from the results of a whole building energy model.

1. Enter the modeled annual energy consumption information by first selecting the Energy Type and associated Units, and then entering a value under Modeled Total Annual Energy Consumption.
   • If more than one energy type is supplied to the building (e.g. electricity and natural gas), enter each value on a separate line. If more than two energy types are supplied to the building, click the Add another energy button to add additional lines as needed.

The US National Renewable Energy Laboratory (NREL)’s PVWatts Calculator Application Program Interface (API) is used to estimate the energy production of grid-connected photovoltaic (PV) energy systems for the building’s Estimated Area for Collectors. It utilizes location-specific data and is applicable globally.

1. By selecting the Use Default Values? box, the Zero Code Energy Software automatically generates the building’s Estimated Area for Collectors by dividing the Gross Floor Area by the Number of Stories and applying a perimeter reduction factor. The calculator will also input default parameters and values for Module Type, Losses, Array Type, Tilt, Azimuth, and Inverter Efficiency.
2. If more accurate values are available for the building’s Estimated Area for Collectors or for the On-Site PV System parameters, deselect the Use Default Values? box and modify the inputs as appropriate.
3. Specify any additional On-Site PV Systems by clicking the Add another PV System button.
   • If the building contains only one On-Site PV System, this step may be skipped.
   • Note: On-Site PV Systems located off the building but on the building site (e.g. in the parking lot) may be included separately (if the system parameters are different than those on the building) or may be aggregated with systems on the building itself (if the system parameters are the same).

1. Click Generate Results at the bottom of the page in order to display your Estimated Building Energy Consumption and Renewable Energy Requirements, as well as the On-Site PV Generation Potential and associated PVWatts Results.
2. Select either metric or imperial units at the top right of the page.

Estimated Building Energy Consumption

• Prescriptive code pathway: Estimated Building Energy Consumption is based on a code compliant prototype modeled by Pacific Northwest National Laboratory.
• Performance code pathway: Estimated Building Energy Consumption is the inputted Modeled Annual Energy Consumption.
• Note: Actual building energy consumption will vary from modeled results. 

The Total Renewable Energy Required equals the Estimated Building Energy Consumption.

• The On-Site PV Generation Potential is estimated using the US National Renewable Energy Laboratory’s PVWatts Calculator Application Program Interface (API) and is based on the building’s Estimated Area for Collectors and system parameters entered in On-Site PV Systems.
  • Note: This value is for informational purposes only.
• Remaining Off-Site Procured Energy is equal to the Total Renewable Energy Required minus the On-Site PV Generation Potential.
  • Note: This value assumes that all of the estimated On-Site PV Generated Potential is generated.

On-Site PV System

• Rated Capacity is the direct current capacity at standard rating conditions (assumes the collector is oriented directly towards the sun and that the solar insolation is 1,000 W/m2).
• Estimated Area for Collectors is the sum of the entered Estimated Area for Collectors for each On-Site PV System.

The Estimated Building Energy Consumption appears if the Prescriptive Code Pathway is selected.

The Estimated Energy Consumption graph and table display annual building energy consumption and end uses based on a code compliant prototype building modeled by Pacific Northwest National Laboratory. Actual building energy consumption will vary from modeled results.

• Note: These values are for informational purposes only. The Zero Code does not require specific energy end use values.

The displayed results are derived from the US National Renewable Energy Laboratory (NREL)’s PVWatts Calculator Application Program Interface (API). The monthly energy production of grid-connected photovoltaic (PV) energy systems is estimated based on the building’s Estimated Area for Collectors, system parameters, and location. The FileID is the solar file selected based on the building location (latitude and longitude). The FTE Solar Hours is derived from the solar file.