The building is located in the science and technology park Savoie Technolac in the capital of the Savoie department, Chambery. The administrative premises of the Institute of Solar Energy (INES), its laboratories and educational center are located on an area of 7,500 m2. The total project budget was 20 million euros, of which construction costs amounted to 15.4 million.
HELIOS was supposed to become an energy efficient building according to the order of the tender, which was held in 2007: this is not surprising, given the specialization of the client-institute. The architects had to design a building that would not emit CO2, that would not use fossil fuels and coolant. In addition, the eco-standards of the 2007 level had to be met: energy consumption below 27 kWh per m2 per year and meeting at least 40% of energy needs from the sun. The authors of the project exploited these constraints as the driving force of the project and tried to make HELIOS a model for green building.
The building is compact: this made it possible to reduce heat losses and the distance between different parts of Helios. Its shell is "super-thermally insulated", and the "cold bridges" are insulated from the outside. The building is oriented with respect to the wind rose and the angle of incidence of the sun's rays. Thus, the north wind in summer provides natural ventilation. It is captured by its "seamy side" wing tilted at an angle of 30 ° with 280 m2 of solar collectors; the working side is facing south. Collectors provide 40% of the building's heating needs. The solar panels located on the roof are also oriented to the south.
The atrium with glazed ceilings, which, depending on the situation, can be completely or partially covered with a screen, also provides natural light and ventilation to the building. The glazed facades are covered with sun screens.
Also among the eco-components of the project are a pellet boiler heating the building and an economical plumbing system.
The northern, concrete façade of Helios houses the world's largest sundial, created by the eminent explorer Denis Savoie, former chairman of the French Astronomical Society.
