A Renovation Proposal for Zero-Energy Houses: Outline of Building Planning and Evaluation of Thermal Environment

Abstract

Considering the effects of electricity shortages caused by natural disasters in Japan, residential energy efficiency is essential. In addition, excessive housing stocks in Japan have highlighted the importance of expertise in renovation methods for zero-energy houses (ZEHs). Therefore, we designed and built a ZEH as a refurbishment of steel-structure industrialized housing to acquire knowledge on ZEH design and renovation. The renovation uses a highly insulated volume against a low insulation volume, which is assumed to be an existing house. The space between the low-insulation wall facing the outside and the high-insulation wall surrounding the main living space functions as a sunroom and called a loggia. By opening and closing the inside and outside windows according to the season and time of day, the loggia functions as a passive system to reduce the air-conditioning load. In this paper, the outline of the building plan of the experimental house and the evaluation of the thermal environment are presented.