Electric heating guide

Best Electric Heating for a Garden Room

How to choose between electric radiators, underfloor heating and a small electric wet-heating system for a garden room or annexe.

Key checks

For one room, direct electric heating may be simplest.
For an annexe with multiple rooms or hot water, a wet system may make sense.
Check the submain capacity before selecting heater output.
Good insulation and controls often matter more than brand.
Occasional-use spaces benefit from fast response and frost protection.

When to call an engineer

If the problem involves fixed wiring, high-current heating equipment, repeated tripping, unvented hot water or uncertainty about the supply arrangement, testing is safer and usually faster than swapping parts.

Related specialist pages

Start with insulation and intended use

A garden office used eight hours a day needs a different heating strategy from an occasional gym or hobby room. Floor, roof and wall insulation, glazing and air leakage can dominate the heat demand.

Direct electric versus wet electric heating

For a single small outbuilding, a direct electric panel or underfloor system is often simpler than installing a wet system and electric boiler. Larger annexes with several rooms and hot-water demand may justify a wet system, but only after the electrical supply and cable route are assessed.

Submain capacity matters

The outbuilding supply must accommodate heating alongside sockets, lighting and any other equipment. The existing protective device and cable cannot be assumed suitable simply because spare ways exist in a consumer unit.

Technically reviewed by Berkshire Electric Heating

Reviewed 9 September 2026 · NICEIC-registered electrical work · G3 unvented hot-water qualified · Dimplex Pro / Quantum installer training.

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