Our Psi-Therm software is the leading Finite Element Mesh analysis tool available for the analysis of thermal bridges in construction components. This powerful design tool is validated to ISO 10211, with automatic mesh generation in order to ensure accurate results in accordance with the applicable standards. Exclusively available to Passivate customers, the software now comes with a boundary condition database for analysis according to BR497 and Passive House  conventions. Saving you the need for complicated spreadsheets and numerous external calculations, the software produces U-values, Psi-values and Frsi-values, producing a comprehensive report in accordance with the requirements of the international standards.


  • Input Heat/energy source to model effects of underfloor heating or buried water mains etc.
  • Automatically draw materials in square, rectangular, circular, oval or I-beam shapes
  • Heat flux vector arrows now included with advanced vector settings
  • Template editor allows you to change what appears on the reports and include your company logo etc.
  • 2D drawing tool allows you to embellish your models with ISO hatch database, custom hatches, colour fill (monochrome & colour fading) & much more
  • New boundary condition tables to reflect changes in EN ISO 13788 for surface condensation risk analysis
  • Extensive materials database (DIN 4108-2)
  • Heat flow representation
  • English / German language options
  • Anisotropic material input
  • Editable report print layouts
  • Temperature & heat-flux scales
  • Isotherm presentation in black or colour
  • Isotherm labelling
  • Advanced boundary condition labelling


The finite element mesh calculation is performed in accordance with EN ISO 10211.  Boundary conditions according to BR497 and Passive House are available in the boundary condition tables. Both the Psi-value and Frsi values are determined automatically following the analysis.


To ensure your analysis is performed in strict accordance with ISO 10211, the software automatically generates and refines the mesh size in order to meet the convergence criteria. This also limits processing time required by not over-complicating the mesh.


The Psi-Therm software uses a CAD platform, meaning the user benefits from advanced drafting tools to generate thermal bridge models quickly and easily, as well as being able to import .dwg and .dxf files of any AutoCAD release version.

Some drafting tools include;

  • Guides / auxiliary path
  • Editing (lines, …)
  • DXF / DWG import


  • Temperature curve
  • Isotherms
  • Infra-red (IR) display
  • Finite element mesh
  • Isoflux lines
  • Heat flux
  • Undisturbed U-values
  • Boundary conditions
  • Dew-point curve, moisture saturation point, dew period, evaporation period


  • Text
  • Dimensions
  • Position of text
  • Temperature point markers
  • Temperature & heat flux scales


  • DIN database
  • Manufacturers Database
  • Limestone
  • Lever
  • YTONG Multipor
  • Fermacell


The report can be output to many formats including PDF, JPEG, direct to printer and many more. The comprehensive report satisfies all the requirements of ISO 10211 & BR497. Alternatively, the printed content can be limited to the input data, materials listings or the mathematical calculation depending on the user requirements. The print layout can be edited by the user to display only selected images of the model, as well as integrating your own corporate logo into the printed report.


Many editing tools are available for the adjustment of the construction model. Components can be selected, moved, re-sized or re-shaped individually or as blocks, making the editing process quick and simple. Individual points on polygons or boundary conditions can be moved at the click of an icon and easily snapped to neighbouring polygons!


Psi Therm 2D & 3D provides the user with an accessible and easy-to-use interface to construct detailed building sections to determine heat flows & surface temperatures. The software automatically calculates psi-values & fRsi values, and generates comprehensive reports in accordance with the relevant standards & conventions for building regulations compliance. With Psi Therm, the user can improve on standard construction details, providing a significantly improved Y-factor and superior building energy rating, while eliminating mould-growth risk.


London training course taking place 14th - 16th March 2016! Don't miss out on this opportunity to learn how to carry out thermal bridge assessment in 2D & 3D, with our hands-on course. The course is aimed at professionals working in the Passive House area, however is of interest to anyone who wants to understand how to calculate thermal bridges. The course will present all the methods required by the Passive House Institute for ambient junctions as well as the ground floor connections, never before presented in English until now! To book your place click here or go to our pricing page. Click here to download the course brochure.


As competent assessors under Part L1a as well as members of the Irish National NSAI Accredited thermal modellers scheme, we can offer you support for any of your project needs. We also provide third-party certification of analyses to all Psi Therm license holders in accordance with the requirements of BR497, ISO 10211 & ISO 10077-2. For more information on this service please contact us.


Design By: Business Helper