Architecture, Building and Structure Design H2O House by Niroop Kumar Reddy Nallari H2O House is a private residence in an urban residential area of Hyderabad. The house is designed for a family of four and covers an area of 12500 square feet. Indoor and outdoor water bodies support passive cooling and lower indoor temperatures during the day. Light weight fly ash bricks and thermal insulation sheets are used as masonry to limit heat transfer. Large openings on opposite walls allow cross ventilation, and solar panels are placed on the terrace. Spaces are zoned vertically according to privacy, with shared rooms below and bedrooms above.