Free U-value calculators
Contents |
[edit] Introduction
U-values (sometimes referred to as heat transfer coefficients or thermal transmittances) are a measure of how effective the elements of a building's fabric are as insulators. That is, the degree to which they prevent heat from transmitting between the inside and the outside of a building. The lower the U-value of an element of a building's fabric, the more slowly heat is able to transmit through it, and so the better it performs as an insulator.
It is important to understand the physics, mathematics, practicality and impact of U-values before moving onto the calculation of U-values. However there are an increasing number of software packages that include U-value calculations within them along with other functions and many simple online U-value calculators.
There is an article on Designing Buildings about U-values and a page called Thermal bridging in buildings both of which will give some background to the subject along with a number of other related articles on Designing Buildings.
It is important to understand that U-value calculations can vary dramatically as a result of the way the are calculated and the factors that are considered it is therefore important to understand concepts in order to assess the accuracy of any calculators that are used.
Whilst Designing Buildings does not endorse any of the following and suggests the users seek professional help or guidance if they are unclear on any detailed points, below is a list of free or minimally priced U-value calculators. They are divided into sections as these may influence some of the factors that are considered.
[edit] U-value calculators developed by consultants
- https://www.elmhurstenergy.co.uk/u-value-calculator/
- https://www.ikonografik.co.uk/free-area-weighted-u-value-calculator/
- https://jpatechnical.com/products/
- https://www.ths-concepts.co.uk/how-to-calculate-u-values/
[edit] U-value calculators developed by other organisations
- https://www.ubakus.de/u-wert-rechner/?
- https://greenbuildingcalculator.uk
- http://www.energiberakning.se/U_value/U_value.aspx
- https://www.changeplan.co.uk/u_value_calculator.php
- https://www.yourspreadsheets.co.uk/u-value-calculator-to-bs-en-iso-6946.html
[edit] U-value calculators developed by product manufacturers
- https://insulation-uk.com/technical-services/tools/online-u-value-calculator
- https://bim.rockwool.co.uk/u_value/
- https://uvaluecalculator.ecotherm.co.uk/calculator/
- https://www.knaufinsulation.co.uk/uvalue-calculator
- http://bguvalue.techlit.co.uk
- https://k.systems/ewi-tools/u-value-calculator/
- https://u-valuecalculator.com/gb/
- https://www.superglassuvalue.co.uk/calculator
- https://www.swisspacer.com/en/caluwin
[edit] Related articles on Designing Buildings
- Conventions for calculating linear thermal transmittance and temperature factors.
- Conventions for U-value calculations (BR443 2e 2019).
- Emissivity.
- g-value.
- k-value.
- Heat loss.
- Heat transfer.
- Insulation.
- Limiting fabric parameters.
- R-value.
- Standard Assessment Procedure SAP.
- Thermal admittance.
- Thermal bridge.
- Thermal resistance.
- U-value conventions in practice: Worked examples using BR 443.
- U-What?
- What do design professionals need to know about U-value calculation conventions?
[edit] External references
Featured articles and news
We're expanding our collaborative mission by launching DB Intelligence, an exclusive market research advisory panel. Built environment professionals can now get paid to share their expertise on industry trends, products and services.
Panel members receive direct financial incentives for participating in research projects like short surveys, 1-2-1 interviews and focus groups. Register today to shape the future of the construction sector.
Planning condition discharge in England and Wales
A brief exoplanation from a building compliance expert, with further links.
Overheating guidance and tools for building designers
Guidance for dealing with element of building fabric control that have increasing importance.
Shading for housing, a design guide
From the Good Homes Alliance and British Blind and Shutter Association.
UK Standard Skills Classification (SSC)
A shared framework for describing skills needs.
Social media ban consultation comes to close
CIOB urges UK Government to consider social media’s role in careers guidance in ban debate.
The latest of eight Skills England apprenticeship units
The addition of battery manufacturing welcomed by ECA with a warning about the risks of fast-tracked apprenticeship units.
Building Control Independent Panel final report
A precis of a key report led by Dame Hackitt with full recommendations and link to the government response.
Building Safety recap April, 2026
A short and longer run-through of the month, with links to further information and sources.
CIAT May 2026 briefing.
From medieval scribes to modern word art.
ECA welcomes crackdown on late payment and push for clean energy, whilst CIOB seek fixed cladding removal timeframes.
Cyber Security in the Built Environment
Protecting projects, data, and digital assets: A CIOB Academy TIS.
Managing competence in the built environment
ITFG publishes new industry guide on how to meet the ICC principles.
The UK's campaign to reduce noise pollution: Mythbusting, articles and topic guides.






















Comments
[edit] To make a comment about this article, click 'Add a comment' above. Separate your comments from any existing comments by inserting a horizontal line.