Mounting and material
A flush-mounted enclosure sits inside a wall cavity and finishes level with the plaster. It looks tidy and is the norm in masonry buildings, but it needs a niche cut in advance and cannot be moved. A surface-mounted enclosure bolts onto the wall surface. It is thicker and more visible, but it needs no cavity, dissipates heat better and is the only sensible option in thin partitions, timber structures and retrofits.
Plastic enclosures are cheaper, lighter and do not need earthing of the body. Metal enclosures contain a fire inside the panel instead of feeding it, and their body must be bonded to PE. In a wooden house the enclosure must be metal — a burning plastic box against a timber wall is exactly the failure the rules exist to prevent. In both EU and CIS practice this is treated as mandatory for combustible building structures.
IP rating and size
The IP number states protection against solids and water. Indoor dry rooms are fine with IP20 or IP30. A garage, a cellar, an unheated utility room or a summer house wants IP44 or better. Anything genuinely outdoors needs at least IP54, a sealed door gasket and cable glands at every entry, plus UV-stable material if it sees sunlight.
Enclosures come in standard module counts — typically 12, 18, 24, 36 and 54 — arranged in rows of 12 or 18 modules. Count the module widths from your shopping list, then add spare capacity: at least 20–30% free rail, as explained in panel reserve. A packed panel means replacing the enclosure to add an EV charger or a garden line later, which is the most expensive change in the whole installation. Wide devices such as voltage relays and three-phase incomers must fit on one rail — they cannot be split across two rows.
Where a panel may go
- Permanently accessible without moving furniture, ladders or opening a locked room.
- Not inside bathroom or shower zones, and not where it can be splashed.
- Not directly above a cooker, sink, hob or heating appliance.
- Not inside a sealed cupboard with no ventilation, and not behind a hinged door that blocks it.
- Operating handles roughly 1.4–1.8 m above the floor, so an adult can reach every device standing normally.
A transparent door lets you read the labels without opening anything and keeps dust off the terminals. With children in the home choose a lockable door or one with a tool-operated latch: modular handles are attractive and easy to flip. Whatever the door, the circuit labels belong on the inside face where they stay readable, and the final installation and testing still belong to a licensed electrician.