ASHRAE’s New Tool for 90.1 ECB

ASHRAE’s New Tool for 90.1 ECB

by Joanne Choi

July 13, 2016

At the start of this year, ASHRAE released a free web application for the Energy Cost Budget (ECB) method of ANSI/ASHRAE/IES Standard 90.1-2010. The new application was developed as a tool to assist with showing a building project’s compliance with the standard. We at Cyclone Energy Group use the ECB method all the time, so we decided to give it a try!

First, what is the ECB method and what is it for?

Depending on local jurisdiction, new buildings may need to comply with ANSI/ASHRAE/IES 90.1-2010, which is the Energy Standard for Buildings Except Low-Rise Residential Buildings. [Side note: In the city of Chicago, new buildings must comply with International Energy Conservation Code (IECC), but IECC states that commercial buildings may comply by following ANSI/ASHRAE/IES 90.1 per IECC Section C401.2] Under ANSI/ASHRAE/IES 90.1, new buildings may take three different paths to comply:

  1. Section 6.3, Simplified Approach Option for HVAC Systems
    This option is typically used for small buildings with simple systems.
  2. Section 6.4, Mandatory Provisions & Section 6.5, Prescriptive Path
    This option is useful for larger buildings with complex systems.
  3. Section 11, Energy Cost Budget Method & Section 6.4, Mandatory Provisions
    This third option is for buildings that cannot meet all of the prescriptive requirements of the first two options, or for buildings that explore alternative building designs. An energy model is used to show compliance, by comparing the proposed building design and budget building design, and their associated costs, Design Energy Cost (DEC) and Energy Cost Budget (ECB), respectively.To show compliance via the ECB method, documentation must be provided that shows the energy use and cost of the proposed building design and budget building design, input and output reports of the simulation program, energy use breakdown, unmet heating and cooling hours, and any error messages. ASHRAE’s new web application was created to help with documenting this method!
Review of the Tool

Until the release of this new web application, ASHRAE only provided PDF compliance forms found in the 90.1-2010 User’s Manual. All calculations had to be completed separately and then input into the PDF form. The form often has to be modified per project, and many firms create their own forms and spreadsheets.


Based on the use of this tool for recent projects at Cyclone Energy Group, this new web application appears to be easy to use, allows for customized entries, and automates calculations between energy use and energy cost. All project information is saved online and is thus accessible on any device connected to the internet, and results can be easily exported in excel format for clients and project records.


The web application currently does not allow for a user to “invite” other users to a project. While results can be shared with others by exporting in excel format, only the user who created the project has access to the project information in the web application. If ASHRAE is planning to release new versions of the web application, I hope it includes the capability for multiple users from the same team to see, update, and export information on the same project.

Have more questions? Want to know more? Email us at for information!