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Performs hourly simulations for single family, multifamily, and mobile homes. Comprehensive analysis tool includes tools for retrofitting heating and cooling systems, building envelopes (insulation and infiltration), windows and doors, hot water, ventilation, lighting and appliances, and more. Weather normalizes utility bills for comparison to performance of model. Highly accurate calculations which consider waste heat (baseload), solar heat gain, and fully interacted energy savings calculations. Create individual energy improvements or packages of interactive improvements. Also performs load sizing. Generates XML file for upload to online database tracking systems. Complies with HERS BESTEST. Approved by the U.S. Department of Energy for use in Weatherization Assistance Programs. Screen Shots


weatherization auditing software, BESTEST, Home Performance with ENERGY STARŪ auditing tool, retrofit, single family, multifamily residential, mobile homes, HERS ratings, load sizing.


BESTested, DOE approved for weatherization (single family, multifamily, and mobile homes).

Expertise Required

Basic computer skills, knowledge of building science, building performance contracting or weatherization retrofit techniques.


Over 1,000.


Weatherization, Home Energy Raters, Home Performance with Energy Star Contractors, Insulation and Mechanical contractors, Mechanical or Energy Engineers performing multifamily building energy analysis.


Building components libraries are used to input building geometry and thermal characteristics, heating and cooling equipment and system characteristics, lighting, appliances, ventilation, and hot water. Imports utility bills and daily weather data.


20 user-selected, formatted reports printed directly by TREAT; generates custom program-designed reports for weatherization, home performance programs or HERS providers. Exports project data in XML format which may be uploaded to online database and tracking system.

Computer Platform

CPU: Pentium 300 or higher (600 MHz recommended); RAM: 256 MB (512 MB recommended); operating system: Windows XP and Windows Vista. Internet access required for software registration.

Programming Language

Delphi and FORTRAN


Comprehensive and highly flexible whole building retrofit tool, easy to use graphic user interface which includes libraries of building components (walls / surfaces, windows, doors, appliances, lighting, heating and cooling, and hot water). Performs utility billing analysis including weather normalization. Calculations consider solar heat gain and waste heat generated by baseload and fully interacted savings from energy retrofit measures.


Not recommended for commercial buildings with complex HVAC systems.



Performance Systems Development Inc.


124 Brindley St
Ithaca, New York 14850
United States


607-277-6240 x252






Visit the Web site for information and current pricing.

TREAT software was created through a partnership between Taitem Engineering and Performance Systems Development Inc., under the sponsorship of the New York State Energy Research Development Authority. TREAT is currently developed and supported by Performance Systems Development. TREAT utilizes the SUNREL building physics simulation engine developed by the National Renewable Energy Laboratory.