1  Construction industries                                  
15  General building contractors                            
152  Residential building construction                      
1521  Single-family housing construction                    
1522  Residential construction, n.e.c.                      
1531  Operative builders                                    
154  Nonresidential building construction                   
1541  Industrial buildings and warehouses                   
1542  Nonresidential buildings, n.e.c.                      
16  Heavy construction, except building                     
1611  Highway and street construction                       
162  Heavy construction, except highway                     
1622  Bridge, tunnel, and elevated highway                  
1623  Water, sewer, and utility lines                       
1629  Heavy construction, n.e.c.                            
17  Special trade contractors                               
1711  Plumbing, heating, air-conditioning                   
1721  Painting and paper hanging                            
1731  Electrical work                                       
174  Masonry, stonework, tile setting, and plastering       
1741  Masonry, stone setting, and other stonework           
1742  Plastering, drywall, and insulation work              
1743  Terrazzo, tile, marble, and mosaic work               
175  Carpentry and floor work                               
1751  Carpentry work                                        
1752  Floor laying and floor work, n.e.c.                   
1761  Roofing, siding, and sheet metal work                 
1771  Concrete work                                         
1781  Water well drilling                                   
179  Miscellaneous special trade contractors                
1791  Structural steel erection                             
1793  Glass and glazing work                                
1794  Excavation work                                       
1795  Wrecking and demolition work                          
1796  Installing building equipment, n.e.c.                 
1799  Special trade contractors, n.e.c.                     
