Energy Efficient Design Protocol for Sustainable Pitch Roof Modification from Flat Roof

Pitch roof modification from flat roof transforms the flat roofs of multi-story buildings into the pitch roofs to improve the building function and landscape effect provided that the building structures and the foundation bearing capacity meet the requirements, which normally commits to improve the thermal insulation performance of the top layer and to solve the problems such as the top layer leakage. This study developed an optimal efficient design protocol for pitch roof modification from flat roof through comparative analysis. The case study used an existing building in Hangzhou city and in the process of energy consumption simulation on pitch roof modification from flat roof whereby control variables were used to keep consistent building materials, building environments, and meteorological conditions. The indoor environment of the building top floor with different gradients settings were simulated in groups, and hourly temperature, monthly heat gains and loss, and energy consumption of each model were analyzed. In results, we found a consistent trend in building energy performance of the different model. With the increase of the slope gradient, the building energy performance is higher. This study provides important reference for future pitch roof modification from flat roof projects in terms of building energy efficiency.