Welcome - more than 6000 users for the free version

USai 3.0 calculates the heat transfer coefficient of walls and predicts the risk of damaging condensation on the wall's interior surface. It can be used to quickly model ranges of facade renovation options and to determine their respective U values (overall heat transfer coefficient).

USai 3.0 provides valuable data to support the decision making process in building renovation projects. It's intuitive interface and our outstanding customer support will enable you to quickly generate reliable results and realize project time and cost savings.

USai 3.0 is connected to the product databases of several major building materials suppliers through the materialsdb.org system.


Free version features:
  • Project concept management
  • Heat transfer coefficient calculation for both homogeneous and inhomogeneous walls, including effects of in-floor heating and plane air cavities (SIA180, EN ISO 6946)
  • Connection to the MaterialsDB.org database
  • Results presented in both graphical and numerical form
  • Can calculate the annexes from the EN ISO 6946 (mechanical fixation and air)
  • Multilanguage capability: English, French, German, Italian


Additional features in the full version:
  • The dynamic thermal characteristics of the wall are accounted for according to the EN ISO 13786 standard. (damping factor, dynamic heat transfer coefficient, thermal admittance)
  • Calculates the risk of internal condensation and the quantity of condensate according to the EN ISO 13788, EN ISO 6946 and SIA180 standards
  • Life Cycle Assesment calculation following the SIA2032
  • Includes the Meteonorm monthly database which provides worldwide meteorological data to support the condensation calculations
  • SIA2028 Meteorological data (monthly data)



Supported operating systems: Windows 98, Windows NT4, Windows 2000, Windows XP, Windows Vista. Use on a Mac OS X system possible with a Windows emulator.