Big Ladder Software

Welcome to Big Ladder!

We are a Denver-based company dedicated to providing software and services for the building energy modeling industry. The company name reflects our mission to “help our clients reach new heights”.

Peter Ellis, President of Big Ladder, founded the company in 2009 after a six-year career at the National Renewable Energy Laboratory in Golden, Colorado. Today we are a team of five programmers, engineers, and scientists with a unique combination of expertise in software development, computer simulation, and building science. Over the past several years, the company has experienced steady growth and achieved significant success and recognition in the industry.

We specialize in all things related to the EnergyPlus simulation engine. We provide software tools, training, support, and consulting services for EnergyPlus to mechanical, architectural, and design engineering firms across the US.

Software Tools

As a software company we handle all phases of software development: design, implementation, testing, documentation, support, and training. We have a special passion for open-source software. Our current open-source projects include Elements, Kiva, and Params.

As members of the EnergyPlus Development Team, we have over 15 years of collective experience programming EnergyPlus. We have been involved with developing component algorithms, user interfaces, and other tools for EnergyPlus. As developers we are able to delve into the program source code to help debug users’ problems.

Training Services

We currently offer various training workshops for professionals. We offer in-person public and private (in-house) EnergyPlus training workshops. We have trained scores of new users in the intricacies of EnergyPlus in workshops at US and international locations.

We offer public and private OpenStudio training workshops. We are licensed through the National Renewable Energy Laboratory as official training providers for OpenStudio.

We also offer public and private DesignBuilder training workshops. We are authorized through DesignBuilder Software (UK) as the official training providers for DesignBuilder in the US.

Support Services

We offer hourly support services for EnergyPlus and OpenStudio by phone and by email. We are licensed through the National Renewable Energy Laboratory as official support providers for OpenStudio.

Consulting Services

We exclusively use EnergyPlus and OpenStudio to perform whole-building energy modeling and have modeled numerous real-world buildings ranging from commercial to residential to US Army buildings. We specialize in complex projects and large-scale projects such as technology screening studies and market sector analyses.


For more information, contact us at: