What This Tool Can Do for You

  • This web application automates the calculations needed to show a building project’s compliance with ASHRAE/IES Standard 90.1-2010 using the Energy Cost Budget (ECB) Method described in the standard.
  • The calculations are based on the ECB Method Compliance Forms found in the 90.1-2010 User’s Manual.
  • Input your project parameters and then calculate your proposed design’s projected performance and compliance—no need to build your own spreadsheet.
  • Output your results in Microsoft® Excel® for your clients and project records.
  • The app is accessible from your desktop, tablet, or other device anywhere.
  • Set up an account and store your project information in one place (not visible to other users) for easy reference and comparison.

Energy Cost Budget (ECB) Method

Section 11 of Standard 90.1 describes the ECB Method, an alternative approach to demonstrating compliance of a building design with Standard 90.1. Compliance with Section 11 is described in detail in Section 11.1.4 of the standard.

With the ECB Method, a computer program is used to calculate the design energy cost for the proposed building design and to calculate the energy cost budget for a budget building design. In the budget building design, which is a variant of the proposed building design, all mandatory and prescriptive requirements of the Standard are applied. In other words, the energy cost budget represents the building as if it complied with the Standard. The design energy cost for the proposed design cannot exceed the energy cost budget.

(Note: The energy cost budget and the design energy cost calculations are applicable only for determining compliance with ANSI/ASHRAE/IES Standard 90.1-2010. They are not predictions of actual energy consumption or costs of the proposed design after construction. Actual experience will differ from these calculations due to variations such as occupancy, building operation and maintenance, weather, energy use not covered by this standard, changes in energy rates between design of the building and occupancy, and precision of the calculation tool.)

ASHRAE/IES Standard 90.1

ASHRAE/IES Standard 90.1 has been a benchmark for commercial building energy codes in the United States and a key basis for codes and standards around the world for more than 35 years. This standard provides the minimum requirements for energy-efficient design of most buildings, except low-rise residential buildings. It offers, in detail, the minimum energy-efficient requirements for design and construction of new buildings and their systems, new portions of buildings and their systems, and new systems and equipment in existing buildings, as well as criteria for determining compliance with these requirements.

Online Help

For detailed help on how to use this web application, click here.