Unmasking hidden energy poverty: Indoor environmental assessment of central-southern Chilean housing

This exploratory case study examines how conventional energy-poverty (EP) indicators, such as the M/2 and 2 M thresholds, overlook households that limit energy use or endure unhealthy indoor conditions. It combines five-minute monitoring (370,000 records) with surveys in eight Chilean apartments during winter 2023. We found that 60 % of “regular-consumption” homes failed to meet the WHO temperature standard of 18 °C, and under-consuming homes averaged just 15.4 °C with > 80 % relative humidity and CO₂ > 1350 ppm. Using M/2 and 2 M thresholds, which were tailored using electricity consumption data from local households in Concepción over a five-year period (2018–2022), dwellings were classified as EP by under-consumption (G1, ≤37 kWh/pc), no-EP (G2, 37–148 kWh/pc), and EP by over-consumption (G3, ≥148 kWh/pc). Kruskal–Wallis tests confirmed significant between-group differences (p < 0.05) for all environmental variables. G3 achieved 19.2 °C, 60 % RH, and safe CO₂ levels, but at a higher energy cost. Chi-square analyses linked heater self-restriction and reduced ventilation to low-consumption groups (p < 0.01), while multivariate correspondence associated thermal comfort with regular heater use. Despite the small sample, the study demonstrates that current EP metrics overlook health-critical dimensions of comfort, air quality, and occupant behaviour, thereby misclassifying vulnerable households by ignoring health-relevant conditions and behaviours. These findings support urgent reforms of Chile's energy-efficiency subsidy schemes and warrant replication across Latin America's growing stock of multi-family housing. Future work should couple long-term monitoring with data to quantify health impacts. Such evidence can inform global debates on just energy transitions today. • Integrated metric reveals hidden energy poverty beyond consumption data. • Five-minute monitoring shows 60 % homes below WHO temperature. • Statistical tests link self-restriction and poor indoor air quality. • Revised thresholds enable fairer subsidies and retrofit policies.