🧠 Installer-trusted since 2012 💷 Trade pricing 📦 Volume & OEM discounts 🚚 Next-day UK dispatch

Metal vs Plastic Enclosures — Which Should You Use?

Enclosures & Components

Metal vs Plastic Enclosures

Both materials are used throughout UK installations. The choice usually follows the location, the rating needed and any requirements for the type of premises.

Quick answer

Metal (steel) enclosures are robust and are the usual choice for indoor consumer units and distribution boards. Plastic enclosures resist corrosion and suit outdoor and weatherproof installations. Check how any requirement for non-combustible enclosures applies to your premises before you specify plastic.

Side by side

Metal (steel) Plastic
Typical rating IP40 indoor boards IP65 weatherproof boards
Robustness Very robust, resists impact Good, but can be damaged by impact or UV over time
Corrosion Needs a protective finish, such as powder coating Does not corrode
Earthing Metal enclosures require suitable earthing or bonding Insulating, no earthing of the enclosure needed
Typical use Indoor consumer units and distribution boards Outdoor EV, solar and weatherproof applications

Regulatory points to check

BS 7671 includes a requirement for consumer units in domestic premises to be made of, or enclosed in, non-combustible material (Reg 421.1.201), which is one reason metal is the usual domestic choice. How that applies to a particular plastic unit depends on what it is, where it is installed and the manufacturer’s documentation, so check before specifying.

For ratings, see IP40 vs IP65 enclosures.

Shop enclosures

Metal IP40 and plastic IP65 enclosures and boards.

Enclosures

Frequently asked questions

Do metal enclosures need earthing?

Yes. A metal enclosure containing electrical equipment needs suitable earthing or bonding, following BS 7671 and the manufacturer’s instructions.

Is plastic suitable outdoors?

Plastic enclosures rated IP65 or higher are commonly used outdoors, with correct glands and installation.

Which should I use for a domestic consumer unit?

Metal is the usual choice indoors. Follow BS 7671 and the manufacturer’s guidance for the specific unit and location.

Enclosures & ComponentsIP40 vs IP65 EnclosuresConsumer UnitsFully Assembled Consumer Units ExplainedDistribution BoardsTPN 3-Phase Distribution Boards ExplainedHeat PumpsHeat Pump Protection Units Explained

Not sure what your install needs?

Use the Product Finder →

Electrical Protection Solutions

View all

Available Chargers

View all