Relation between indoor thermal environment and renovation in Liege residential buildings

Indoor thermal environment monitoring has been done in 20 residential buildings of Liege
city followed by questionnaire based comfort survey amongst the occupants of 85 houses in
order to record their preference and expectations about indoor thermal environment in winter
and spring season. It is found from the analysis that change of glazing has a minimum or even
sometimes an adverse effect on the existing indoor environment due to the absence of proper
insulation of the rest of the building envelope. It is observed that in winter there is a sudden
drop in indoor temperature and also overheating in summer. This is due to unplanned
installation of glazing which actually increases the fenestration area ratio leading to higher
indoor temperature fluctuation and causes discomfort. It is also important that the occupant’s
preference and expectations as well as overall assessment of indoor environment needs to be
consider towards energy efficiency improvement.