Description of the project in English ARCHAS EKO-1 - the first iterative residential building project with AFEE quality brand in Lithuania. The project utilized a rational space. Design decisions are not typical, however they a simple - natural solar energy is used for compensation of heat losses. The project goal was to give the Lithuanian market residential building project that meets the requirements of a passive house and cost as much as any other iteratyve house. Three main directions of development of the project – the Aesthetics, Functionality and Energy Efficiency – to combine into a single whole. The result - an iterative energy-saving (passive), residential building project with AFEE quality brand. The total residential building area – 166,34 sqm. Inside the house are planed : four bedrooms, sitting-dining room, kitchen, two bathrooms, a clean room, tambour, basement with technical and storage rooms. There is planned a lot of closets to storage goods, clothes, etc. Building benefits - energy costs for heating are about 80% lower than in traditional home, house is functional and aesthetic. Our engineers designed the optimal heating-ventilation-cooling model that provides the necessary comfort and use very little energy. Architectural solutions. The main house windows oriented to the south. This allows the use of solar heat during the winter, terrace roof does not allowe to grill the rooms during the summer and protects from the rain. Skylights illuminates rooms of the attic floors. Light also falls into the first floor through these skylights. This project is designated to a modern family, which is looking for environmental aesthetic quality, functionality and energy saving.