Hea 04 - Thermal comfort

Acceptable deviations – ISO 7730:2005 category B - KBCN1714

Acceptable deviations from category II thermal modelling criteria can be made in accordance with CEN 16798-2:2019 Anne E, only when the thermal comfort assessment uses CEN 16798 to demonstrate compliance. Where this is the case, up to a 6% deviation based on yearly occupied hours can be accepted when demonstrating compliance.  ^{Note: this KBCN no longer allows the deviations to be used for ISO 7730:2005. However, for assessments where the assessor has advised the project team based on the original KBCN, prior to this update, this will be honoured if you provide evidence of this in your assessment. KBCN wording 16 Jan 2025 - 10 Jul 2025: ~ Acceptable deviations from the ISO 7730:2005 category B criteria thermal modelling criteria can be made in accordance with CEN 16798-2:2019 Annex E. Up to a 6 % deviation based on yearly occupied hours can be accepted when demonstrating compliance ~}

10 Jul 2025 - KBCN updated following further review of relevant standards

---

Adaptability for a projected climate change scenario – Winter conditions - KBCN1715

Where future climate change scenario projections in winter indicates a higher temperature and, therefore, more thermally comfortable climate compared to the current winter temperatures, it can be assumed that the winter conditions within the climate change scenario are met based on the thermal modelling of current winter conditions. Justification must be provided for each project confirming that the future winter conditions will be met with the current heating system. In a warming climate the heating system needs to be sized for the beginning of its lifespan, whereas the cooling systems need to be sized for the end of their life span (Ref: CIBSE TM55: 2014)

---

Assessing thermal comfort – Residential buildings - KBCN1408

CIBSE TM59 can be used to demonstrate compliance with the thermal comfort requirements for residential buildings, instead of ISO 7730:2005. This is to recognise the most up to date methodology relating to the assessment of homes.

26 Jan 2025 - Updated to apply to multi-residential buildings (long-term stay) and scheme applicability extended to account for this.

---