AECOM
NYSE:ACMAECOM, together with its subsidiaries, provides professional infrastructure consulting services worldwide. It operates in three segments: Americas, International, and AECOM Capital. The company offers planning, consulting, architectural and engineering design, construction and program management, and investment and development services to public and private clients. It is also involved in the investment and development of real estate projects. In addition, the company provides construction services, including building construction and energy, and infrastructure and industrial construction. It serves transportation, water, government, facilities, environmental, and energy sectors. The company was formerly known as AECOM Technology Corporation and changed its name to AECOM in January 2015. AECOM was incorporated in 1980 and is headquartered in Dallas, Texas.

EMCOR Group
NYSE:EMEEMCOR Group, Inc. provides construction and facilities, building, and industrial services in the United States and the United Kingdom. It offers design, integration, installation, start-up, operation, and maintenance services related to power transmission, distribution, and generation systems; energy solutions; premises electrical and lighting systems; process instrumentation; low-voltage systems; voice and data communications systems; roadway and transit lighting, signaling, and fiber optic lines; computerized traffic control systems, and signal and communication equipment; heating, ventilation, air conditioning, refrigeration, and geothermal solutions; clean-room process ventilation systems; fire protection and suppression systems; plumbing, process, and high-purity piping systems; controls and filtration systems; water and wastewater treatment systems; central plant heating and cooling systems; crane and rigging services; millwright services; and steel fabrication, erection, and welding services. The company also provides building services that covers commercial and government site-based operations and maintenance; facility management, maintenance, and services; energy efficiency retrofit services; military base operations support services; services for indoor air quality; floor care and janitorial services; landscaping, lot sweeping, and snow removal services; vendor management and call center services; installation and support for building systems; program development, management, and maintenance for energy systems; technical consulting and diagnostic services; infrastructure and building projects; modification and retrofit projects; and other building services, including reception, security, and catering services. In addition, it offers refinery turnaround planning and engineering; welding; overhaul and maintenance; instrumentation and electrical; and renewable energy services. The company was incorporated in 1987 and is headquartered in Norwalk, Connecticut.

Comfort Systems USA
NYSE:FIXComfort Systems USA, Inc., together with its subsidiaries, provides mechanical and electrical installation, renovation, maintenance, repair, and replacement services for the mechanical and electrical services industry in the United States. It operates through two segments, Mechanical and Electrical. The company offers heating, ventilation, and air conditioning systems, as well as plumbing, electrical, piping and controls, off-site construction, monitoring, and fire protection. It also engages in the design, engineering, integration, installation, and start-up of mechanical, electrical, and plumbing (MEP) and related systems in new buildings; and renovation, expansion, maintenance, monitoring, repair, and replacement of MEP systems in existing buildings. In addition, the company provides remote monitoring of power usage, temperature, pressure, humidity and air flow for MEP and other building systems. It serves building owners and developers, general contractors, architects, consulting engineers, and property managers in the commercial, industrial, and institutional MEP markets. Comfort Systems USA, Inc. was founded in 1917 and is headquartered in Houston, Texas.

Quanta Services
NYSE:PWRQuanta Services, Inc. provides infrastructure solutions for the electric and gas utility, renewable energy, communications, and pipeline and energy industries in the United States, Canada, Australia, and internationally. The company's Electric Power Infrastructure Solutions segment engages in the design, procurement, construction, upgrade, repair, and maintenance of electric power transmission and distribution infrastructure and substation facilities; installation, maintenance, and upgrade of electric power infrastructure projects; installation of smart grid technologies on electric power networks; and design, installation, maintenance, and repair of commercial and industrial wirings. This segment also offers aviation services; emergency restoration services; and other engineering and technical services; design and construction solutions to wireline and wireless communications, cable multi-system operators, and other customers; and training for electric workers, as well as training for the gas distribution and communications industries. The company's Renewable Energy Infrastructure Solutions segment is involved in engineering, procurement, construction, repair, and maintenance of wind, solar, and hydropower generation facilities, as well as battery storage facilities; and provision of engineering and construction services for substations and switchyards, transmission, and other electrical infrastructures. The company's Underground Utility and Infrastructure Solutions segment offers design, engineering, procurement, construction, upgrade, repair, and maintenance services for natural gas systems for gas utility customers; fabrication services for pipeline support systems and structures and facilities; and engineering and construction services for pipeline and storage systems, and compressor and pump stations. The company was formerly known as Fabal Construction, Inc. and changed its name to Quanta Services, Inc. in November 1997. The company was incorporated in 1997 and is headquartered in Houston, Texas.