Thomas Kellenberger

Inretis Holding AG provides building technology and shell services which includes plumbing, heating, ventilation and roofing. The firm’s services include strategic energy planning, engineering office for energy and building technology, energy procurement, energy services, plant and pipeline construction for chemicals/pharmaceuticals and infrastructure, heating, refrigeration, solar technology, sanitary, water supply, sewage engineering, heavy current, photovoltaic systems, swimming pool technology, building envelope, maintenance, repair, service, low power, ICT, bath and kitchen maintenance. The company was founded in 2005 and is headquartered in Chur, Switzerland.

Poenina Holding AG provides building technology and building shell services. It specializes in plumbing, heating and cooling, ventilation and air conditioning, roofing, as well as plant construction. The company was founded by Jean-Claude Bregy in 2010 and is headquartered in Glattpark, Switzerland.