Calculation of heat flows, thermal bridges, isotherms and Uf values according to EN ISO 10077-2:2018 as well as Ufr, Ueg and Ucg values according to ISO 15099 and NFRC.

Professional calculation

Uf, Ψ, thermal bridges, isotherms, fRsi as well as Ufr, Ueg and Ucg values



according to EN ISO 10077-2:2017-07 and EN ISO 10211-2:2017-07

Powerful functionalty

for the thermal calculation of windows and facades


Imported CAD files can be prepared by automatic detection and correction of CAD errors. Thus, complicated components and systems can be analysed and calculated with short computing times and small data sizes. The integrated FEM calculation kernel enables the most accurate results.


  • Highly automated geometry preparation of CAD data (.dxf & .dwg)
  • Detailed transfer of CAD data incl. radii and bevels
  • New solver and new calculation core with automatic FEM meshing
  • Automatic FEM meshing can be controlled flexibly and specifically, resulting in high calculation speeds
  • Calculation according to the "radiosity model" (new cavity model according to EN ISO 10077-2:2018) and with equivalent conductivity (EN ISO 10077-2:2012/2018)
  • Simple definition of foils, coatings and surface properties using line drawings
  • Automatic material allocation based on CAD layers
  • Gas filling for inter-pane spaces according to DIN EN 673 freely mixable
  • Automated Uf calculation of window and façade profiles
  • Psi-values of thermal bridges and insulating glass spacers according to EN ISO 10211 and EN ISO 10077-2
  • Ug-values of multi-pane insulating glass according to EN 673
  • U-values of any construction according to EN ISO 6946
  • Calculation of isotherms, surface temperatures and temperature factor according to DIN 4108-2/-3
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WINISO® Funktion Übersicht
  • Certified by independent testing institutes
  • Results are internationally recognised
  • Extremely user-friendly operation
  • Reliable partner for long-term customer satisfaction
  • Market-ready solutions even before the relevant laws and standards are passed, together with permanent updating – our solutions are always up to date


PVC-window: Uf and ψg according EN ISO 10077-2


Calculation of frame U value Uf and edge bond ψ value ψg according to EN ISO 10077-2 for a PVC window

Uf according EN ISO 10077-2


Calculation of frame U value Uf according to EN ISO 10077-2 for an aluminium window

ψ- and fRsi-value


Installation ψ value and temperature factor fRsi according to DIN 4108 supplement 2



2D moisture calculation on the basis of DIN 4108-3

Window: Uw zone model according to ISO 15099


Calculation of the U values Ufr, Ueg, Ucg for the Uw zone model according to ISO 15099. Boundary conditions according to NFRC.

Window: Sash bar in glazing cavity


Thermal bridge at a sash bar integrated into the glazing air gap, accoding to ISO 10211.

Window: Meeting rail with two glazing inserts


Automatic calculation of the Uf value of a meeting rail profile with two glazing inserts according to EN ISO 10077-2

Underground garage ceiling: condensation prevention


Proof of freedom from condensation of a truss under an underground garage ceiling according to DIN 4108 supplement 2

CAD Import

CAD import and clean up


WINISO® imports CAD data as DWG, DXF and STEP. Efficient tools for CAD preparation create a seamless transition from CAD to FEM during data transfer.



During the generation and processing of the polygons, the essential features and contours of the design are obtained and the foundation is laid for efficient and fast FEM calculation.

Polygon Search Flood Fill


The Flood Fill polygon recognition gives the user an intuitive, powerful and robust tool for preparing even problematic CAD data.

Clean joints


The joint clean-up automatically corrects offset errors from the CAD data and removes incidental details. The result is a coherent design that focuses on the essentials for the FEM calculation.

Tools – Part 1


With an extensive CAD tool set, the imported CAD data can be easily and flexibly reworked and supplemented

Tools – Part 2


With an extensive CAD tool set, the imported CAD data can be easily and flexibly reworked and supplemented

Project processing

Surface machining


Surfaces reflect the geometry in the WINISO® FEM model. The structure of the simulation project is completely defined in just a few steps.

Material assignment


Automatic assignment of materials to layers and automatic detection of profile cavities and boundary condition surfaces for a speedy and error-resistant model definition

Boundary condition


With the automatic detection of cavities and the flexible definition of boundary conditions and surface properties, almost any problem can be modelled quickly and precisely.



The definitions of frame cavities and spaces between panes from a wide range of standardisation are implemented in WINISO®: DIN EN ISO 10077-2, EN 673, DIN EN ISO 6946, ISO 15099.

Frame according to EN ISO 10077-2


WINISO® implements both calculation methods for window profiles with cavities provided for in DIN EN ISO 10077-2 in accordance with the standard: the equivalent conductivity method and the radiosity method introduced in 2017. Automatic checks ensure a consistent and standard-compliant calculation approach in all details.

ISO 15099


WINISO® enables the calculation of window profiles and glazing according to the specifications of ANSI/NFRC-100 and ISO 15099 according to the requirements of the US standardisation for the international market


Presentation of results


Construction, temperatures, heat flows and humidity profiles can be represented flexibly and meaningfully by isothermal lines, false colours and isobars

Auswertung nach EN ISO 10077


The mathematical verification for windows according to DIN EN ISO 10077 can be carried out efficiently and in compliance with standards with the automated determination of Uf, Psig and Uw.
Certification ift Rosenheim

Wärmebrücken nach EN ISO 10211


The manual determination of thermal bridge coefficients Psi according to EN ISO 10211 offers a universal tool for the thermal evaluation of building structures, window details such as mullions and façades.

Evaluation according to DIN 4108 and EN ISO 6946


WINISO® provides elementary results such as the U-value according to EN ISO 6946 and the temperature factor fRsi according to DIN 4108:2 with one click

Present results


Present your results clearly and comprehensibly as a printout, PDF or in Word – with a set of predefined templates or customised with the template designer

Save projects, manage data


The SommerGlobal user database manages your WINISO® projects in a structured and clear manner in projects with any number of positions and the assignment of processors. Interfaces to WinSLT, WinTHS and GLASGLOBAL make interdisciplinary work efficient.


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What our clients say

„We are enthusiastic about the WinIso® software. Among other things, the high accuracy and speed of calculation are outstanding.“

Hörmann KG

Founded in 1935, the Hörmann Group is Europe's leading supplier of doors, which are developed and produced in 27 specialised factories in Europe, North America and Asia.

Contact: Stephan Ongsiek –

„Interpane Glasgesellschaft mbH has been an enthusiastic customer of Sommer Informatik GmbH for many years. The calculation with WinIso® also worked quickly and effectively for us after a short training period, which is why we can only recommend this tool.“

Interpane Glasgesellschaft mbH

Interpane Glas Industrie AG is a German flat glass manufacturer based in Lauenförde. The company manufactures glazing products at ten locations in Germany, Austria and France.

Contact: Steffen Schäfer –

"WINISO® is a powerful and for us very important tool, which effectively implements the requirements of the newly revised ISO 10077-2 and professionally supports the user in performing the calculations."

Ingenieurbüro Bauwerk

The engineering office has been active since 1998 and offers services in the field of building physics and window technology.

Contact: Mr. Deckert –

"Due to the structured and professional design of the software, it was possible for us to carry out demanding calculations with WINISO® directly without much effort."

Ensinger GmbH

Ensinger GmbH was founded in 1996 and processes engineering plastics into semi-finished products, finished parts, profiles and compounds. The headquarters of the internationally active company is Nufringen in Baden-Württemberg.

Contact: Sven Rhode –


Term explanation



Profiles can be displayed as a 3D view. 3D evaluation, both in temperature fields and in heat flow fields.
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Is a measure of the thermal quality of a building component. The higher a U-value is, the more heat passes through a component. In WINISO® you have the option to determine the linear U-value based on the selected point as well as to calculate the U-value (total).
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ISO 15099

Our expert software WINISO® has been extended by the calculation according to the American standard ISO 15099. The add-on "ISO 15099" is available for this purpose. With the add-on "ISO 15099", the relevant calculations of Ufr, Ueg and Ucg can be carried out according to ISO 15099 and NFRC..
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Condensation water

Use the add-on to calculate humidity using WINISO®. WINISO® is used to calculate relative humidity, vapour diffusion and condensation.
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Material fields

Materials from the material database in WINISO® can be assigned to the generated surfaces of a component with the corresponding material colours or hatchings using various functions.
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In the representation of the temperature fields you get a coloured representation of the surface temperature in the individual surfaces of a component. The colour representation is in the value range between 0° C and 20° C.
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fRsi factor

The temperature factor, called the fRsi factor, is a criterion for the mould risk at a wall connection (connection of a window to the adjoining wall) and is the basis of DIN 4108-2.
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Heat flows

The heat flow indicates how much heat flows through a construction per time. The cause of the heat flow is a temperature difference.
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The length-related heat transfer coefficient, called Ψ-value, indicates the heat transfer through the edge seal of windows and is based on DIN EN ISO 10077-2. The Ψ-value is given in watts per metre and kelvin.
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The U-value of a frame, called Uf-value, indicates the heat transfer through the area of the frame.
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Isotherms are curves of equal temperature that make the quality of a building component visible in terms of condensation and mould risk. The 10°C and 13°C isotherms are prominent for condensation and mould formation.
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WINISO® offers extensive, intuitive and fast editing options for CAD files. The operation is adapted to common CAD software for this purpose. A CAD editor is included in WINISO®.
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