U-value calculator

Do you need a U-value calculator?

Are you looking for an user-friendly and versatile U-value calculator? Well this short review summarizes various solutions to your u-value calculation problematic ! Check out our propositions below.

What are the solutions for my U-value calculation?

The two following instruments can be used to evaluate the U-value:

For which use cases, this estimation can be employed ?

U-value measurement

Typical applications include measurement of building insulation, windows, and various industry driven R&D fields.

Thermal energy enters buildings mainly from the heating system and from solar irradiation.

The energy exchange between the building and the outside is focused through the roof, walls, windows, and thermal bridges e.g. balconies, into the soil, and through exchange of ambient air.

Every building is a complex thermal system and to optimize these systems (for example to reduce heating costs), precise data is required.

As the measurement set up for glass differs due its low thermal capacity to the influence of radiation for opaque materials.

  • Assessing the status quo : A precise status quo assessment of the U-value before a refurbishment increases the quality of the overall planning.
  • Check before project handover : In case of dispute between project partners, a non-invasive U-value measurement can increase the transparency between the project partners.
  • Heat bridge and mold detection : Dew point assessment via room humidity and surface temperature measurement. Quantitative assessment of heat bridges via U-value measurement.
  • Applications in R&D, quality control : Exact measurement tool for U-value measurement in R&D of new insulation materials. Tool for quality control in the production of insulation materials

Discover our full set of application notes, case studies and whitepapers in our download & PDF section available here.

greenTEG’s solution: Building performance evaluation with the U-value kit


  • Easy to mount: with normal adhesive tape to fix the sensor to any wall or window.
  • Easy to transport with its transportation box.
  • Real-time measurement directly on your laptop.
  • Fast measurement: without following the ISO guidelines, the measurement is performed in less than an hour.
  • Easy analysis with our user-friendly software!
  • Versatile equipment various applications.
U value kit

Our measurement-approach uses a heat flux sensor and two temperature sensors (see image below). This approach is standardized in ISO 9869, ASTM C1046 and ASTM C1155. This is the only method which delivers reliable quantitative in-situ information about a building envelope. Read about a U-Value measurement with our gSKIN® U-Value KIT in a case study from ETH Zurich. In a study sponsored by the Swiss Federal Office of Energy and conducted by Hässig Sustech, the gSKIN® U-Value Kit was used to measure the insulation quality of walls in older buildings. The English abstract is available on page 3 of the study which can be accessed here. We also offer a cloud-based, wireless solution for U-value, R-value, and temperature measurements.

Six-step protocol to measure your building insulation performance


Choose an optimal measurement spot on the building element of interest.

On the inside of this spot, place the heat flux sensor, and one temperature sensor.

On the outside of this spot, place the second temperature sensor.


Connect all three sensors to the data logging unit.

Start the measurement process (via your Laptop).

Evaluate the U-value of the wall element with the software included .

They trusted our equipment for their project

The Swiss Federal Office of Energy supported us with its expertise during the development of our technology. In 2010, greenTEG got certified by the Commission for Technology and Innovation (CTI). Together with our partner Climate KIC we exhibit our technology at the Umweltarena Spreitenbach.

Are you in urgent need of a U-value calculator ?

Find below our list of local distributors for greenTEG’s heat flux sensors and measurement kits, to fasten the process and accelerate your project!

Feel free to contact us for any questions regarding your U-value measurement or project.

U value calculator