A critique on on-going retrofit approaches to existing high mass historic building forms with heat sink capacity

Abstract

The research presents a critique on unrealized heat sink capacity of Colombo’s historic British period buildings. The work discusses how on-going inappropriate retrofitting approaches to these buildings can hinder the passive heat sink capacity of high thermal mass envelopes. The research performed field investigations on selected renovated historic high mass buildings of which most of them are naturally ventilated. Results showed that renovated building interiors become overheated during daytime and night time due to direct and indirect heat gain due to newly introduced retrofit interventions i.e. courtyards and windows. Later, one renovated but critical building was simulated with its original status of physical characteristics by removing all newly introduced design interventions using Design-Builder software program. Results show that the original building performs better than renovated building in maintaining indoor air temperatures lower than outside ambient air temperature during daytime. The work illustrates the efficiency of heat sink effect of thermal mass in historic building forms and challenges the on-going retrofit approaches.