Limbach Holdings, Inc. operates as an integrated building systems solutions company in the United States. It operates in two segments, General Contractor Relationships and Owner Direct Relationships. The company engages in the design, prefabrication, installation, management, and maintenance of mechanical, electrical, plumbing, and control systems, as well as heating, ventilation, air-conditioning (HVAC) system. Its facility services comprise mechanical construction, HVAC service and maintenance, energy audits and retrofits, engineering and design build, constructability evaluation, equipment and materials selection, offsite/prefabrication construction, and sustainable building solutions and practices. The company serves research, acute care, and inpatient hospitals; public and private colleges, universities, research centers and K-12 facilities; sports arenas; entertainment facilities, and amusement rides; passenger terminals and maintenance facilities for rail and airports; government facilities comprising federal, state, and local agencies; hotels and resorts; office building and other commercial structures; data centers; and industrial manufacturing facilities. The company was founded in 1901 and is headquartered in Pittsburgh, Pennsylvania.