Economic and thermal evaluation of different uses of an existing structure in a warm climate

Accounting for nearly 40% final energy consumption, buildings are central to European energy policy. The Directive on Energy Performance of Buildings establishes a benchmarking system known as cost-optimality to set minimum energy performance requirements in new and existing buildings. This paper applies the cost-optimal methodology to an existing structure located in the Mediterranean area (Southern Italy). The building is composed of two units that have been considered for different uses: hotel and multi residential. Several energy efficiency and renewable measures have been implemented both individually and as part of packages of measures. The cost-optimal solution has been identified as able to balance energy consumption and costs from financial and macroeconomic perspectives. In comparison with the reference buildings, the cost-optimal solution decreases primary energy up of 90% and CO2 emissions up to 87% at the lowest cost. Thermal dispersions through the envelope can be limited using a suitable combination of insulating materials while a variety of technical variants are selected, such as VRF (variant refrigerant flow) systems, heat pumps with fan coils associated with controlled mechanical ventilation, solar thermal and photovoltaic. This paper illustrates how the development of cost-optimal retrofit projects. It shows the most suitable efficiency measures for a building having two different uses and provides guidance for similar case studies related to a warm climate.JRC.C.2-Energy Efficiency and Renewable