Thermal energy refurbishment status of the Irish housing stock

Abstract

Energy Performance Certificates (EPCs) are issued for buildings constructed, sold or leased across the EU. Using a generalizable methodology this work exploits Ireland's EPC national dwelling stock database to determine the thermal refurbishment status of Ireland's housing stock. It is estimated in 2014 that; i) 58% of walls were insulated at a mean overall heat loss coefficient or U-value of 0.66 W/m2K, ii) 67% of roofs were insulated at a mean U-value 0.37 W/m2K, iii) 97% of windows were double-glazed, and iv) 53% of floors were insulated to a mean U-value of 0.59 W/m2K. The (i) extent of thermal refurbishments and (ii) high degree of energy-efficiency improvements in Ireland contribute significantly to household energy usage per square metre being 9% below the EU 27 average in 2010, and the average energy efficiency of Irish housing having improved by over 34% between 1995 and 2011 (2.5% per annum). The distinction between the thermal efficiency of pre-thermal building regulation and post-thermal building regulation dwellings, whilst still valid, is lessening. A strong association between dwelling age and energy efficiency often-made is diminishing as retrofits continue to be carried out. The long-held view that the majority of Irish dwellings are thermally sub-standard is no longer valid.