On the improvement of indoor environmental quality, energy performance and costs for a commercial nearly zero-energy building

The compliance with the indoor environmental quality (IEQ) requirements should be considered when designing retrofit actions for the refurbishment of existing buildings. The research is aimed to reduce the imbalance between the visual and thermal domains through the improvement of different design parameters in compliance with the nearly zero-energy building (nZEB) requirements. The article proposes a novel approach based on the integrated lighting, thermal, and energy dynamic simulation, to evaluate the overall building performance according to energy saving, cost effectiveness, and IEQ multi-criteria. Different energy efficiency actions, in terms of insulation materials, glazing solutions, and control strategies of the solar shading devices, have been applied to an existing office building-type. The analysis shows the possibility to design the refurbishment of an existing building into a nZEB while ensuring visual and thermal comfort. However, the not negligible costs lead to an incompliance with the cost-effectiveness requirements.