| E | SK | FIXED CONSTRUCTIONS |
| E03 | KL | WATER SUPPLY; SEWERAGE |
| E03B | UKL | INSTALLATIONS OR METHODS FOR OBTAINING, COLLECTING, OR DISTRIBUTING WATER (drilling wells, obtaining fluids in general from wells E21B; pipe-line systems in general F17D) |
| E03C | UKL | DOMESTIC PLUMBING INSTALLATIONS FOR FRESH WATER OR WASTE WATER (not connected to either water-supply main or to waste pipe A47K; devices of the kind used in the ground E03B , E03F); SINKS |
| E03D | UKL | WATER-CLOSETS OR URINALS WITH FLUSHING DEVICES; FLUSHING VALVES THEREFOR |
| E03F | UKL | SEWERS; CESSPOOLS |