Giving the high angular resolution and the high sensitivity of the required THEMIS observations, it is fundamental to minimize the turbulence caused by the Sun heating the ground surface during daytime as well as the turbulence within the building due to thermal unbalance. Multiple elements of the THEMIS building acts to reduce such turbulence:

• As with all modern professional solar observational facilities, the collection of the solar light by the telescope is done at several tens of meters of altitude, in order to be above the most turbulent layers that are close to the ground. In the case of THEMIS, the telescope is located at 22.5 meters high, under the dome of the THEMIS building.
• White gravel has been placed around building to increase the reflection of light in the surroundings of the building, and thus reduce ground heating and turbulence.
• Rounded shapes of the building and building orientation favors stable/laminar wind circulation around the building.
• The building location, aligned with the morning prevailing winds, optimises the wind flow in the morning and hence improves the morning observations which usually correspond to the time of the day with the best sky quality.
• White-painted aluminium cladding and the tightly fitted dome aperture to the telescope allows to reduce heat absorption and heat transfer, hence reducing turbulence within the building.
• Inner concrete tower, independent of the main building, to prevent the transmission of vibrations to instruments

The 9m rotating dome has been designed and installed by EIE. Its main role is to protect the telescope from the winds, the rain and the snow and solar erosion, while allowing observations of the sky in any directions. The dome has a spherical shape and it is divided into two parts: the rotating dome which rotates around the azimuth axis (dome lower part) and the rotating cap (the dome upper part) which rotates around the pseudo elevation axis with an inclination of 45°. The rotating cap is provided with an aperture for the telescope observations. The combination of the azimuth and pseudo elevation rotations allows the aperture to follow the movements of the telescope with extreme precision. The building insulation is guaranteed by thermo-acoustic insulating panels, plus aluminium perforated sheets.