-- National Renewable Energy Lab – Golden, CO
-- International Building Performance Simulation Association (IBPSA)-USA – San Francisco, CA
-- Rocky Mountain Institute – Boulder, CO
-- Big Ladder Software – Denver, CO
DOE Funding: $495,000
Project Term: 2013 – 2015
Funding Opportunity: Commercial Buildings Integration core funding
Project Website:
Related Projects: EnergyPlus, Radiance, OpenStudio, SBIR - Big Ladder

Project Objective

Although many aspects of energy modeling can be automated, the setup of energy analyses and the assimilation of results and their translation into practical recommendations—i.e., the process of asking the right questions, interpreting the answers, and asking follow-on questions—is very much a human task. Effective energy modeling requires more than just capable, efficient, up-to-date software. It requires capable, efficient, and up-to-date energy modelers.

In addition to developing open-source energy modeling software, BTO is also partnering with IBPSA-USA—the U.S. chapter of the International Building Performance Simulation Association—to collate, curate, and sometimes create resources that support the modeling community.

One significant resource developed under this partnership is the BEM Library, an organized collection of minimal-requirement and best-practice guidelines for various energy modeling scenarios, such as design assistance, code compliance, and savings prediction. Developed by a working group led by RMI (Rocky Mountain Institute), the BEM Library is intended to serve a reference for ASHRAE Standard 209P “Minimal Requirements for Simulation-Driven Design-Assistance for Nonresidential Buildings”, a companion to the 90.1 and 189.1 non-residential energy efficiency standards. By setting expectations for energy modeling tasks and deliverables, the BEM Library could also effectively create a service contract between modelers and their clients—architects, engineers, building owners and operators, and potentially other energy-efficiency service providers. In addition to content for modelers themselves, the BEM Library includes high-level literature for modeling clients and even sample modeling contract language.

A newer and very exciting resource is, a peer-to-peer question-and-answer site for energy modelers. Similar to the popular site for software developers, allows users to post questions, answer other users’ questions, and subscribe to topics of interest and expertise to receive alerts. Both questions and answers receive votes so that frequently asked questions and good answers bubble to the top of searches. Users that ask good questions, provide good answers, or generally act as good citizens are rewarded with points and badges, which in turn give them prestige, give their actions more clout, and sometimes unlock new site capabilities. Launched in early September 2014, had over 170 users and 60 active discussions after just one month.

In addition to the BEM Library, IBPSA-USA also hosts and maintains a number of other resources, including BEMBook wiki knowledge base, a database of building energy modeling publications, and a database of BEM educational materials and offerings.

Project Impact

IBPSA is the primary professional organization for energy modelers and a natural channel partner for organizing and hosting modeler resources like the BEM Library and the Building Energy Simulation Tool Directory, historically hosted by BTO. It is also a potential partner for and organizing and helping to deliver training and educational services.

The BEM Library and ASHRAE standard 209P will articulate and clarify energy modeling service expectations and deliverables. It should both improve the quality of energy modeling services and increase the frequency with which they are contracted.

The site is showing great promise in its first two months of activity and could be a significant new resource for modelers.


DOE Technology Manager: Amir Roth
Lead Performer: Kristin Field, NREL; Mike Wilson, IBPSA; and Ellen Franconi, Rocky Mountain Institute

Related Publications

Deru, M.; Field, K.; Franconi, E. (2013) “Building Performance Modeling for Gaining Investor Confidence.” Proceedings of BS2013: 13th Conference of International Building Performance Simulation Association. Chambéry, France.
Franconi, E., et al. (2013) Building Energy Modeling for Owners and Managers: A guide to Specifying and Securing Services. Rocky Mountain Institute, Boulder, Colorado.