The Chamber of Installation Specialists in Bulgaria (CISB) is the universal legal successor of the National Installations Union (NIU), and is a national trade association of the branch of industry of natural persons and legal entities working in the field of heating, ventilation, air-conditioning, refrigerating engineering, electrical engineering and automation, water and gas supply, energy saving technologies, energy efficiency, renewable sources of energy, and environmental protection. The companies and specialists, members of CISB, provide design and research services, expert consultancy, installation and assembly works, production of facilities and equipment, distribution, sales, intermediation services, etc.

CISB was established in April 1995 as a non-profit association, pursuant to resolution of Plovdiv District Court No.6257/1995 on corporate case No.4067/95. CISB is a national association having its head office in Plovdiv and regional representative offices in Sofia, Burgas, Varna and Ruse.

The Chamber of Installation Specialists in Bulgaria keeps the Professional Register of Installers, in which Bulgarian and foreign legal entities and physical persons involved in installation activities on sites in the country are registered.

The Chamber also runs a Vocational training centre, licensed by the National Agency for Vocational Education and Training (NAVET).