Assessment of cost-optimality and technical solutions in high performance multi-residential buildings in the Mediterranean area

• A multi-residential building is selected as reference building for cost optimality assessment.
• Envelope and systems are characterized for a baseline building located in the Mediterranean area.
• Packages of energy efficiency measures are established to assess energy performance.
• Global costs are evaluated to derive the cost-optimal solution.
• Standard and high efficiency buildings are compared.

The European policy framework is focused on reducing energy consumption in the building sector. The recast of Energy Performance of Buildings (EPBD) Directive establishes that minimum energy performance requirements have to be set to achieve cost-optimal levels.A methodology is developed to assess energy and cost effectiveness in new buildings located in the Mediterranean area. Several energy efficiency technical variants are applied to a multi residential reference building selected as a representative model of the national building stock. Primary energy consumption and global costs are evaluated in a number of configurations to derive the cost-optimal solution.The paper shows how economical high efficient buildings can be obtained at a design stage for a warm climate. The selected configuration decreases primary energy consumption by 90% and CO2 emissions by 88% with respect to the baseline building.Results appear useful for comparison with other climates and building types. The paper also points out that the methodology is suitable to guide and support the choice of cost effective energy efficiency measures in compliance with EU requirements.