Three unobtrusive domestic occupancy measurement technologies under qualitative review.

Highlights: [•] Compared three occupancy measurement technologies for domestic energy efficiency. [•] Overall occupancy, room occupancy, number of occupants and location were assessed. [•] Passive infra-red: only good at occupancy detection, but prone to negative false. [•] CO2: highly depends on air circulation, thus only detects overall occupancy reliably. [•] Device-free localisation shows clear potential and requires more research. [ABSTRACT FROM AUTHOR]