A Breathing Buildings guide to understanding policy for energy-efficient interiors and schools. Thermal comfort is defined by more than just a thermometer; it involves the duration and severity of heat exposure.
1. CIBSE Guide A (2006)
The Chartered Institution of Building Services Engineers (CIBSE) established early benchmarks for overheating based on fixed temperature thresholds.
Benchmark: For many buildings, overheating is defined as temperatures exceeding 28°C.
The Three Criteria for Assessing Overheating:
- Duration of Overheating: How many hours the temperature is exceeded.
- Severity of Overheating: How far above the threshold the temperature rises.
- Upper Limit Temperature: An absolute maximum that should never be breached.
| Regulation | Weather File | Criteria | Measure | Limit |
| CIBSE Guide A (2006) | Design Summer Year | Indoor Comfort Temperature | 25°C | Indoor Air Temperature > 28°C for no more than 1% of occupied hours |
| Max Temperature | 28°C |