Operational and embodied energy of residential buildings in the Andean region between 1980 and 2020

The relationship between operational energy (OE) and embodied energy (EE) in buildings is a highly complex issue. In countries with extreme climates and high sustainability standards, efforts are made to reduce OE for climatization with materials and technologies that eventually increase the EE. The case of non-extreme climates such as the Ecuadorian Andean region is different. New building systems and construction elements are introduced in buildings to replicate the model adopted in other climates and, consequently, EE experiments an increase. However, it remains unclear what impact these changes have on OE and in the total life cycle energy. To assess the effects of these construction changes, 40 residential buildings constructed between 1980 and 2020 in Cuenca, Ecuador, were analyzed. Their OE was obtained through energy simulations validated with measurements (Heating plus Cooling, Lighting plus Electrical Appliances) and mathematical calculations (Domestic Hot Water plus Cooking). Their EE values were obtained from prior research. The findings indicate that buildings in the Ecuadorian Andean region have experienced an increase in total life cycle energy: EE has risen from 1643 to 3600 MJ/m 2 over the last forty years, and OE for heating and cooling has also increased (from 1000 to 2195 MJ/m 2 ), also increasing the total life cycle energy of the building. Unlike in other countries where a reduction in OE demand leads to an increase in EE, in the studied case, the upward trend in EE results in an increase in OE demand.