237310 – HIGHWAY, STREET, AND BRIDGE CONSTRUCTION
Includes roadway construction, bridge structures, paving, resurfacing, grading, drainage systems, and traffic infrastructure improvements.

237990 – OTHER HEAVY AND CIVIL ENGINEERING CONSTRUCTION
Covers large-scale civil projects such as retaining walls, dams, marine construction, earthwork, and specialty infrastructure not classified elsewhere.

237210 – LAND SUBDIVISION
Includes site preparation, grading, utility installation, road layout, and infrastructure development for residential and commercial subdivisions.

237130 – POWER AND COMMUNICATION LINE CONSTRUCTION
Includes installation of overhead and underground electrical transmission lines, fiber-optic systems, and communication infrastructure.

237120 – OIL AND GAS PIPELINE CONSTRUCTION
Includes pipeline installation, welding, trenching, pressure testing, and related support structures for oil and gas transport systems.

237110 – WATER AND SEWER LINE AND RELATED STRUCTURES CONSTRUCTION
Includes water mains, sewer systems, pumping stations, treatment-related structures, and underground utility installation.

236220 – COMMERCIAL AND INSTITUTIONAL BUILDING CONSTRUCTION
Includes office buildings, schools, healthcare facilities, retail, and other non-residential structures.

236210 – INDUSTRIAL BUILDING CONSTRUCTION
Includes factories, warehouses, processing plants, and heavy industrial facilities.

236117 – NEW HOUSING FOR-SALE BUILDERS
Includes construction of single-family homes intended for sale, including speculative and tract housing.

236116 – NEW MULTIFAMILY HOUSING CONSTRUCTION
Includes apartment buildings, condominiums, and mixed-use residential developments.

236115 – NEW SINGLE-FAMILY HOUSING CONSTRUCTION
Includes custom and owner-built single-family residences.

238160 – ROOFING CONTRACTORS
Includes installation, repair, and replacement of commercial and residential roofing systems.

238130 – FRAMING CONTRACTORS
Includes wood and metal framing for residential, commercial, and industrial buildings.

238990 – ALL OTHER SPECIALTY TRADE CONTRACTORS
Includes specialty construction services such as concrete finishing, site-specific installations, and trade services not otherwise classified.

238170 – SIDING CONTRACTORS
Includes exterior siding installation using materials such as vinyl, metal, fiber cement, and composite systems.

238190 – OTHER FOUNDATION, STRUCTURE, AND BUILDING EXTERIOR CONTRACTORS
Includes foundation work, structural reinforcement, exterior envelope systems, and building shell components.

238120 – STRUCTURAL STEEL AND PRECAST CONCRETE CONTRACTORS
Includes steel erection, welding, precast concrete installation, and structural framework assembly.