CIBSE TM68 Monitoring indoor environmental quality: A starter guide for building professionals

Alex Siu-fung Fung, Volkan Doda

The CIBSE Technical Memorandum 68 (TM68) on Monitoring Indoor Environmental Quality (CIBSE, 2022) provides building professionals with a primer on continuous IEQ monitoring by presenting a wholistic picture that includes delineating units and performance metrics, available instruments and sensors, practical sampling consideration and case studies for four principal IEQ aspects. Best practice for collecting and using data gathered from sensors and meters in and around buildings are suggested.


Europeans spend approximately 90% of their time indoors for work, study and living (EVIA, 2022), while nearly 40% of global energy demand is attributed to building sector (UNEP, 2022). The quality of living, health, productivity, and satisfaction of building occupants are generally correlated to the Indoor Environmental Quality (IEQ), which encapsulates four major environmental conditions, namely, thermal comfort, air quality, luminous quality, and acoustic quality (CIBSE, 2015). The average loss of human life expectancy due to particulate pollution alone is estimated to be 2.2 years (AQLI, 2022). Office users can be benefited from interventions in their working environment, in return for their enhanced health, comfort and productivity (Felgueiras et al., 2022). In the post-pandemic era, provision of good IEQ in indoor premises whilst minimizing energy consumption is vital for a return to normal life without sacrificing wellbeing and climate change aversion measures. This is where CIBSE’s new TM68 fills a competence gap by equipping practitioners with guidance on the selection and implementation of tools and methods that can assist with improving thermal comfort, air quality, luminous quality, acoustic quality whilst supporting improvements in energy performance. The next section presents an overview for each of these aspects and they are summarized in Figure 1to 4 for ease of reference.

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