Assessment of Retrofitting Old Residential Buildings in Urban Districts: Expected Performance of Selected Energy Efficiency Measures

Abstract

Developing solutions to face the climate crisis is becoming a challenge not to local and national governments but also to researchers and modern societies. Of these, energy efficiency of buildings is a key topic to control carbon emissions and enhance sustainability. This study contributes to the very limited literature on energy efficiency retrofitting of old buildings in urban areas, in Jordan as well as the neighboring Arab countries. The considered case study is the capital city of Jordan, Amman, with the aim of investigating possibilities and economics of selected retrofitting energy efficiency measures in old residential buildings. The analysis presents the thermal performance of different types of dwellings and energy demand based on real data obtained from official surveys and statistical reports. The developed simulation model examined the impact of each of the studied energy efficiency measures on different types and sizes of housing units under same operating conditions and comparing results with the base case. The adopted retrofitting technique of existing envelops, i.e. external walls and final roofs, depends on boosting thermal resistance, thus, the overall heat transmission coefficient will be reduced. In case of windows, the new double-glazed windows should decrease heat losses as well as the solar heat gain coefficient under different conditions. The maximum savings could be generated in small housing units, in a multi-family building, which represent the major fraction of dwellings, in Amman. This group is the most attractive and challenging due to poor performance of existing envelops and being occupied by low-income families. The stimulated results suggest that such group of houses have remarkable potential of energy savings, of about 22%, resulting from insulating external walls and replacing old inefficient windows. Unfortunately, final roof insulation and replacement of basic appliances, i.e. washing machine and the fridge, would have relatively long payback periods, which made such options not very attractive from the economic point of view. To conclude, there are good opportunities to more green residential buildings through retrofitting programs aiming to control energy demand and expansion in using available renewable energy systems.