Summer thermal comfort in architectural early design workflows.

In recent years, to decrease greenhouse gas emissions as a part of climate change mitigation strategies, adoption of passive house approach, which is amongst the most prominent due to high energy efficiency potential, has gained momentum especially in Europe. On the other hand, global warming of 1.5 °C and 2 °C is expected to be exceeded during the 21^st century and this opens a debate on the summer thermal performance of passive houses. Architects, as main actors of the design process, play a significant role for the early assessment of potentials and risks regarding the building performance. Nevertheless, the use of performance assessments in design workflows is not main stream among architects yet. At this point, for architects to be able to include performance evaluations in their workflows, simplified performance assessment methods and building performance simulation tools integrated with design tools become more significant. In this regard, this study presents a simplified thermal performance evaluation method through a systematic performance simulation in early design phase. To meet the indoor thermal comfort expectations, temperature is one of the key parameters in building design and intensively correlated with the carbon footprint in the use phase. Therefore, thermal comfort is selected as the main performance topic, and a simplified method, namely annual neutral hours, which refers to the capacity of a building to run without active heating and cooling, is presented. In this scope, the paper discusses summer thermal comfort and climate change over a residential building case study by using a Building Performance Simulation tool integrated into a 3D CAD design tool. The results indicate that the proposed methods are applicable to early design workflows and have a potential to give insight to architects by enabling quick and iterative evaluations for the detection of key parameters; thus, solution alternatives. As an additional result of the study, among other parameters, transparent envelope properties and shading elements appear to be significant to meet the expectations for future summer thermal comfort; also, it is seen that the winter performance might slightly benefit from the climate change. [ABSTRACT FROM AUTHOR]