This article examines the traditional design of Japanese homes, insulation techniques, heating systems and tips to keep your house warm in Japan. It explains that traditional Japanese houses are made of wood and paper walls with tatami mats on the floor, which are often insulated with straw or cotton batting. It also discusses climate and temperature in Japan, insulation of Japanese houses, heating systems in Japanese houses, and tips to keep your house warm such as installing weather stripping around doors & windows, adding extra layers on windows & doors, using draft stoppers, utilizing area rugs & carpets etc. This article provides useful information for those considering moving to Japan or living there during cold winter months.