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Where It All Started

In 1992 founder Greg Thomas was elected President of the board of directors for Affordable Comfort Inc. Seeing how quickly building science was advancing as a field, Greg coined the term Home Performance to describe the whole house retrofit industry at an ACI event in California. Shortly after in 1995, Greg formed Greg Thomas and Associates (the precursor to PSD) and initiated the first Home Performance program working with Niagara Mohawk.

By 1998 PSD had been officially formed with its landmark project, Ecovillage at Ithaca, which won a HUD Affordable Housing Award with energy designs by Greg Thomas, receiving international acclaim in Popular Science, NY Times, and the Wall Street Journal.

The first software product was launched in 2000 with funding from NYSERDA. TREAT helped support Home Performance programs and multifamily programs. Later that year, PSD helped launch the NYSERDA Energy Smart loan program for commercial and multifamily buildings.

By 2003, TREAT was pre-approved by DOE Weatherization as the only tool suitable for all building types, from Mobile Homes to High Rise Multifamily. The company continued to flourish, and in 2005 Enterprise Foundation contracted with PSD to calculate energy and carbon savings from the Green Communities Program. Results used to generate over $1B in financing for affordable housing.

From 2006 to 2010 grew steadily with deepening ties to RESNET, Vice President Gore, and the EPA. Investments from Laurel Ridge and Bluehill Capital provide the infrastructure for future growth.

Since 2010 PSD has become an industry leader in Energy Program Implementations, and TREAT software is in use in almost all 50 states.

Our Founder

To know Performance Systems Development is to know Founder Gregory Thomas. A visionary in the energy efficiency field for over 30 years, Greg’s commitment to energy efficiency and building performance is as tireless as his energy is contagious across the company. As the past chair of Efficiency First, and recent board member of RESNET, he is deeply involved at the very top levels of government regulation, industry standards, technology partners, and program management.

He founded the New York Building Performance Contractors Association and is a past president of ACI (Affordable Comfort Inc.). BPI (Building Performance Institute) has acknowledged Greg’s contributions with a lifetime achievement award. Greg has also served in advisory roles for NYSERDA (New York State Energy Research and Development Authority), the U.S. Department of Energy, and a past program director for the USGBC (US Green Building Council).

PSD is on a mission to recruit the best minds in the business. White-collar, blue-collar, or even no-collar roles are frequently popping up. If you don’t see the position you are looking for, please use the form below to tell us a little more about yourself, your experience, and what you are looking for in your next role.


Energy Programs

Designing and implementing cost-effective performance-based energy efficiency programs.

Program QA

Leading provider of QA services supporting energy efficiency programs throughout the country.


PSD Compass is a configurable enterprise solution for energy efficiency programs and implementers.


Technology for large-scale electrification, Heat Pump + Retrofit Toolkit, standardized simulations and tools.

Energy Codes

Expert technical leadership achieving decarbonization, cost-effectiveness, resilience, and equity goals.

HERS Provider

Accredited Home Energy Rating Provider, offering nationwide technical support and services.


Moving the industry forward with PSD’s intimate knowledge of how buildings work.


Join our growing team of energy efficiency professionals to help us save energy to save the planet.