The Importance of Optimising Performance within Retrofit Programmes

Ireland’s Climate Action Plan details a roadmap of measures that seek to achieve net-zero target carbon emissions by 2050. In this context, Ireland has introduced the National Retrofitting Scheme (NRS) which has set a goal of retrofitting c. 30% of existing dwellings to a Building Energy Rating (BER) of B2 by 2030. The route to attaining this rating is dependent on the current specification and configuration of each individual property, therefore it can promote the adoption of retrofit techniques that achieve the required BER rating as opposed to focussing on optimisation of dwelling performance. The pre-cursor to the NRS was the Deep Retrofit Pilot Programme (DRPP) which promoted a fabric first deep retrofit approach, with the outcomes used to inform large-scale retrofit under the NRS. This study appraises, through environmental monitoring, dwellings that underwent a fabric first deep retrofit as part of the DRPP versus dwellings that required minimal intervention to achieve the required BER of B2. It is demonstrated that, irrespective of the retrofit approach, scenarios exist where the approach to achieving the required standard are insufficient to enhance the quality of the indoor environment and may promote conditions for condensation and mould growth. These findings have implications for the policy framework.