Electrical wiring is primarily carried out using two methods: "surface wiring" and "concealed wiring." Concealed wiring involves threading wires through plastic conduits (typically flame-retardant PVC pipes) embedded within walls, floors, or ceilings; these are ultimately covered by plaster or decorative finishes. This method offers a neat and aesthetically pleasing appearance and is currently the standard practice in new home renovations. Surface wiring, conversely, involves securing wires directly onto the surfaces of walls or ceilings and covering them with cable trunking. This approach is frequently employed in the renovation of older homes or when adding supplementary circuits; while the installation process is relatively simple, it does have a certain impact on the interior aesthetics.
Regardless of whether surface or concealed wiring is chosen, there are fundamental principles governing the routing of cables. Wires should be laid along wall edges, ceiling corners, or near baseboards, adhering as closely as possible to horizontal and vertical lines to facilitate easy identification of the wiring layout in the future. High-voltage wiring (power supply lines) and low-voltage wiring (such as network cables and TV cables) must be routed separately; when running parallel, they should maintain a minimum separation distance of 30 centimeters. If the lines must intersect, they should cross at right angles to prevent signal interference. Furthermore, wires should never contain splices or joints while inside the conduits; instead, all connections must be made within switch boxes, outlet boxes, or junction boxes to ensure safety.