Environmental Design Solutions Limited (EDSL) was formed in 1989 to commercially develop Tas Software. EDSL sells Tas software and consultancy services using Tas. EDSL believe that the mixing of development, consultancy and software support leads to a focused software product, with quality support available to end users.

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Tas Version 9.1.3.1

Changes since Tas 9.1.3a


  • Brand new features: The Building Simulator has an automatic checks system to catch potential mistakes in your model before you simulate. Located in the Tools menu, the Pre-Simulation Checks will identify areas to address dependant on the type of project you are running.
  • Greater flexibility: Combined Heat and Power (CHP) systems can now serve any combination of heating, cooling and domestic hot water in any priority order and can now be sized relative to the base load. The panel macros (PV and SHW) now allow the user to select any surfaces as their panels and eliminate the need for a naming prefix.
  • Better interfacing with other programs: Better interfacing with other programs: gbXML import in the 3D Modeller has been vastly improved and the IDF Conversion Utility now accepts version 3 files.
  • Regulation updates: Regulation updates: The UK Building Regulations macro has been renamed the UK and ROI Building Regulations macro to reflect the inclusion of Republic of Ireland regulations. ROI calculations are currently not accredited and have been included for testing purposes only. In line with current terminology, the 'design' building is now referred to as the 'actual' building (an "_actual.tbd" file will be created by the Building Generator). If you run the Building Generator on an existing project, you should delete the existing "_design.tbd" and rename "_actual.tbd" to "_design.tbd" before re-simulating.
  • Updates to the user interface, such as improved drag-and-drop, smarter 3D 'external' wall detection, resizable program windows, more forgiving 'undo' handling, more visible U/R-values and several other 'usability' changes, many of which are as a direct result of customer feedback.

To download Tas version 9.1.3.1, click here.