Japan has a long standing tradition of passive design, though it has become somewhat obsolete concept in the modern industrialized metropolitan area. This house is intended to provide a comfortable environment to those who seek asylum from severe heat wave with humidity during the summer. Natural air ventilation was the first priority upon planning. The breeze from the lake cools down by utilizing vaporization cooling. U shaped plan captures the breeze efficiently. CFD (Computational Fluid Dynamics) simulation was conducted, based on the wind direction/velocity measurement on the site in summer. The deep eaves protect this highly airtight & insulated house from the weather. The depth was evaluated based on the solar radiation angle throughout the year. In summer, it does not let the sunlight in the room. In winter, on the other hand, the sun exposure is maximized to the room.