Thermal comfort and building compliance
PMV Explained: Comfort Prediction& NCC Compliance
Understand what Predicted Mean Vote measures, where it applies under the NCC and how thermal modelling tests whether occupied spaces meet comfort requirements.
A measure of perceived warmth
What Does Predicted Mean Vote Measure?
Predicted Mean Vote (PMV) estimates how a group of occupants is likely to perceive a building’s thermal environment. Its seven-point scale runs from −3 (cold) through 0 (neutral) to +3 (hot). The result is a prediction of average thermal sensation, not a thermometer reading or a direct account of each person’s comfort.
PMV combines six variables:
- air temperature;
- mean radiant temperature, which reflects heat radiated by surrounding surfaces;
- air speed;
- relative humidity;
- metabolic rate, or occupants’ activity level; and
- clothing insulation, or what occupants are wearing.
In a building assessment, these inputs help translate modelled indoor conditions into a predicted comfort result for occupied zones.
Where PMV Fits in the NCC
PMV is not required for a Section J Deemed-to-Satisfy (DTS) assessment. It entered the NCC in 2019 as a thermal-comfort requirement for the JV3 verification method, which had previously focused on achieving a specified energy-consumption outcome. Under NCC 2022 J1V3, occupied spaces must achieve a PMV between −1.0 and +1.0 across at least 95% of occupied-zone floor area for at least 98% of annual operating hours. BERA uses the applicable NCC pathway and project-specific modelling to help clients demonstrate compliance while supporting comfortable, energy-efficientbuildings.
NCC 2025 J1V3: Which Assessment Applies?
Class 5: PMV Pathway
Metric: Predicted Mean Vote
Target range: −1.0 to +1.0
Area test: At least 95% of occupied-zone floor area
Time test: At least 98% of annual operating hours
Inputs: Temperature, radiation, air speed, humidity, activity and clothing
Other Classes: Alternative Options
Metrics: Dry-bulb temperature or peak zone loads
Temperature bands: Generally 18–25°C or 21–24°C, depending on space use
Temperature coverage: At least 95% of occupied-zone floor area
Temperature duration: At least 95% of annual operating hours
Load test: 98th-percentile zone loads versus climate-specific reference limits
Talk to BERA about your project goals. We’ll help you identify the most suitable thermal-comfort measure and a practical path to compliance.