| 918.41 Energy Conservation Consulting |
| 918.42 Engineering Consulting |
| 925.07 Air Conditioning, Heating and Ventilating Engineering |
| 925.31 Electrical Engineering (Incl. Cogeneration Design Services) |
| 925.33 Engineer Services, Professional |
| 925.34 Energy Management Engineering |
| 925.37 Facilities Design Services, Engineering |
| 925.39 Fire Protection Engineering |
| 925.57 Instrumentation/Engineering |
| 925.67 Mechanical Engineering |
| 925.78 Power Generation, Transmission, Distribution - Engineering |
| 925.84 Security Systems; Intruder and Smoke Detection/Engineering |
| 925.89 Telephone Systems/Engineering |
| 925.95 Utilities (Gas, Steam, Electric)/Engineering |
| 925.96 Waste Water Treatment Engineering |
| 925.97 Water Supply, Treatment, and Distribution/Engineering |
| 926.15 Air Quality Monitoring Services |