Thermal Calculations Service
At Attain RTC, in support of the testing facilities we also offer calculation methods for thermal transmittance.
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U-Value
Attain RTC is able to undertake detailed thermal performance calculations in accordance with established European methodologies for building envelope components, including windows, doors and curtain walling systems. This includes assessment of heat transfer and U-values to support compliance, design validation and product development.

We can carry out calculations in line with BS EN ISO 10077-1:2017 and BS EN ISO 10077-2:2017+A1:2025 for windows and doors, as well as BS EN ISO 12631:2017 for curtain walling systems. These standards define the methods for determining thermal transmittance and component-level heat flow, enabling accurate, consistent performance data suitable for regulatory submissions, energy modelling and product classification.
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Trusted by leading UK manufacturers

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Attain RTC has been instrumental in navigating the complex Broof(t4) fire testing requirements for our varied roof build-ups at EverRoof. From Adam’s initial technical guidance to Phil’s expert onsite feedback and Sreya’s seamless project management, the team consistently goes above and beyond. Their deep understanding of regulations and commitment to service makes them an invaluable partner for our ongoing testing needs.

Dave Wilson

EverRoof

I visited Attain RTC in October 2025 to observe BRoof (t4) fire testing carried out on two different roof build-ups. During our time at the centre, we were given a comprehensive tour of the facilities and had the opportunity to meet with members of the team, who were professional, knowledgeable and welcoming throughout. Attain also provided assistance with budget quotations for future testing programmes and were always on hand to offer guidance and support when required. The service provided was efficient and helpful at every stage of the process.I would not hesitate to recommend Attain RTC.

Olivia Breasley

Longworth Group

The testing process was exceptionally thorough, well‑organised, and delivered with a high level of professionalism. Communication was clear throughout, and the insights provided were both detailed and genuinely valuable to our project. We were extremely impressed with the overall service and would highly recommend it to others.

Colm O’Boyle

T&B Contractors

We have been working with Attain RTC from the very beginning and found them to be highly professional offering a high-quality and reliable testing service. They have bought a new and very much welcomed positive approach to the testing process, and quickly established themselves as a market leader in both the quality of service and thoroughness of testing!

Matthew Sexton

BMI Group

Moy have been working with Attain RTC for over a year and continue to return to them for our fire testing requirements. Dealing with Adam and the team is always straightforward, with clear instructions, realistic timeframes, and excellent communication throughout. Their consistent professionalism and reliability make Attain RTC a trusted partner for us.

Will Russell

Moy Group

Having recently commenced working with Attain we find their expertise and willingness to support in a challenging market refreshing.

Steve McIntryre

Viritopia

Vanquish Systems has worked with Attain RTC on multiple projects and continues to do so, finding their approach to testing and classification to be professional, technically robust, and supportive with good customer service throughout. Communication has been clear and focused on regulatory and technical requirements.

Oliver Bate

Vanquish Systems

Working with Attain RTC has been a real pleasure. From the first initial interaction, they’ve demonstrated professionalism, genuine care, and a deep understanding of our needs. They delivered a high-quality service in a very timely fashion, furthermore their attention to detail is excellent. I regard them as a reliable, innovative, and trustworthy solution provider.

Dean Grady

Sika

Oner and the team at AttainRTC are incredibly professional and knowledgeable. They were very good at explaining and assisting us with understanding the testing process and permitting us to observe first hand. We have and will use their services again without hesitation.

Sue Hopkins

Dynamik

I visited Attain RTC in February 2025 to observe a number of BRoof (t4) fire tests. All the members of staff I came into contact with were both friendly and hospitable and I felt comfortable and confident during the course of my observations. Also, there was a requirement for further information after the classification report was issued and Attain RTC provided the necessary details at no extra charge. I would not hesitate to recommend this company.

Dave Wilkinson

Tor Coatings

Opening Hours

08:30 - 17:00 Monday – Thursday
08:30 - 15:30 Friday

General enquiries

enquiries@attainrtc.co.uk

Where to find us

Hangar One, Leeds East Airport, Church Fenton, Tadcaster, North Yorkshire, LS24 9SE

Give us a call

01937 227 640