How to heat an outbuilding like a garage or shed

Garages and garden sheds are often some of the most underused spaces in the home, especially during the colder months.

Whether it’s a garage workshop, a home gym, a garden office, or simply somewhere to enjoy your hobbies, these spaces have huge potential. The main problem is that they’re usually cold, draughty, and not designed with comfort in mind.

The good news is that with the right approach, particularly the use of electric radiators, you can transform a garage or shed into a warm, usable space all year round.

In this article, we’ll look at everything you need to consider, from insulation through to choosing the right electric radiator for your space.

Table of Contents

1. Start with insulation
2. Make sure you have electricity
3. Work out how much heat you need
4. Why electric radiators are ideal
5. Choosing the right electric radiator
6. Garage and shed radiators at TradeRadiators.com

Start with insulation

Before you even think about heating, it’s worth tackling the biggest issue most garages and sheds face, which is heat loss.

Garages are often built from single-skin brick or concrete blocks, while sheds are typically made from timber panels, neither of which are particularly good at retaining heat.

Improving insulation will:

• Keep warmth inside for longer
• Reduce running costs
• Make any heating system far more effective
• Help regulate temperature year-round (cooler in summer too)

The important areas to insulate

In your garage or shed, there are some important places where you can really make a difference in terms of reducing heat loss.

Walls

Walls are one of the biggest sources of heat loss, especially in garages with single-skin brickwork or sheds made from thin timber panels. Adding insulation boards internally (fixed to the inside walls) is often the most practical option, while external insulation can also be considered in some cases. This helps trap heat inside and makes the space much easier to warm.

Roof and ceiling

Heat naturally rises, so an uninsulated roof will allow warmth to escape very quickly. In garages, insulating between roof joists or adding insulated plasterboard can help, while in sheds, fitting insulation boards or mineral wool beneath the roof is a simple and effective upgrade.

Garage doors

Garage doors are often thin and poorly sealed, making them a major weak point for heat loss. Purpose-made insulation kits or foam boards can be fitted to the inside of the door to reduce draughts and retain warmth, making a noticeable difference almost immediately.

Windows

Single-glazed or poorly sealed windows allow heat to escape and cold air to enter. Upgrading to double glazing is ideal, but if that’s not practical, using thermal blinds, heavy curtains, or even window insulation film can significantly improve heat retention.

Floors (especially in sheds)

Cold air can rise from uninsulated floors, particularly in sheds that sit directly on a base or raised platform. Adding insulation boards beneath flooring, or even using thick rugs or rubber mats, can help reduce heat loss and make the space feel much warmer underfoot.

Even basic improvements can make a noticeable difference, reducing heat loss and allowing your heating to work far more efficiently.

• Further reading: The best ways to heat a conservatory

Make sure you have electricity

For most people, the simplest and most practical way to heat a garage or shed is with electric heating.

This is because electric radiators operate independently from your home’s central heating system. Extending central heating into an outbuilding can be costly and disruptive, often requiring pipework to be run underground and additional load on your boiler. In contrast, electric heating is far more straightforward, usually requiring only a suitable power supply to get up and running.

However, this does rely on having electricity available in the space.

If your garage or shed doesn’t currently have power:

• A qualified electrician can run electricity safely from your home
• Additional sockets can be installed exactly where you need them
• A fused spur may be used for a more permanent radiator installation

If you’re planning to use the space regularly (for example as a home office, workshop, or gym), having electricity installed is usually a worthwhile investment. It not only allows for heating, but also lighting, tools, aircon and other essentials that make the space far more practical and comfortable to use.

• Further reading: How efficient are electric radiators?

Work out how much heat you need

Not all garages and sheds are the same, so it’s important to understand your heating requirements before choosing a radiator.

Factors that affect this include:

• The size of the space (including ceiling height)
• Level of insulation
• Number and condition of windows
• Construction type (brick, timber, etc...)
• How you intend to use the space

Using our heating calculator will give you a clear idea of how many Watts (W) or British Thermal Units (BTUs) you need, helping you choose a radiator that can comfortably heat the space. On the Trade Radiators website, heat outputs of electric radiators are displayed in Watts (W) and heat outputs of hot water radators are displayed in BTUs.

Why electric radiators are ideal

Electric radiators are one of the easiest and most effective ways to heat garages and sheds.

Unlike traditional radiators, they don’t rely on your central heating system, which means:

• No pipework required
• Minimal disruption during installation
• Flexible placement
• Simple operation

In some cases, electric radiators can simply be mounted on the wall (or be freestanding) and plugged into a standard 13amp socket, making them a quick and convenient option. However, for a neater and more permanent setup, it’s often better to have the radiator hardwired by a qualified electrician. This removes the need for visible cables, frees up plug sockets for tools or equipment, and is generally a safer solution, especially if you plan to install more than one radiator in the space.

Do not attempt to hardwire an electric radiator yourself. This is something that must be done safely and in line with UK regulations. A qualified electrician will ensure the wiring, load capacity, and circuit protection are all correct, reducing the risk of electric shock, fire, or damage to your system.

An electrician can also advise on the best positioning, ensure the circuit can handle the load, and install smart features such as timers or thermostats if required.

Electric radiators also offer consistent, controllable heat, often with built-in thermostats and programmable settings, making them ideal for spaces you don’t use all the time but want to warm up quickly when needed.

• Further reading: Are electric radiators expensive to run?

Choosing the right electric radiator

There are several types of electric radiators available, and the best choice will depend on your space, layout, and how you plan to use it.

Electric panel radiators

If you’re looking for a straightforward, no-fuss heating solution, electric panel radiators are a great place to start.

• Clean, simple design
• Quick to heat up
• Often made from aluminium for excellent heat conductivity
• Ideal for general garage or shed use

They’re a reliable and cost-effective way to bring consistent warmth into your space.

Electric vertical radiators

If horizontal wall space is limited, especially in sheds or small garages, an electric vertical radiator can be a great choice.

• Makes use of vertical wall space
• Frees up floor area
• Modern, stylish appearance
• Surprisingly powerful for their size
• Perfect for garden offices or hobby rooms where layout matters.

Electric cast iron radiators

For those wanting something a bit more robust, or with a bit of character, electric cast iron radiators are becoming increasingly popular.

• Extremely durable (great for workshop environments)
• Excellent heat retention
• Strong heat output
• Available in a wide range of finishes

Many models can be used freestanding or wall-mounted, giving you flexibility in tighter or more awkward spaces.

Electric column radiators

If you like the traditional look of cast iron radiators but want something a little lighter and more streamlined, electric column radiators are an excellent alternative.

• Classic, timeless design
• Lighter and quicker to heat up than cast iron
• Strong, even heat output
• Available in a range of sizes and finishes

Typically made from steel, electric column radiators offer a nice balance between style and practicality. They bring a bit of character to a garage or shed, which is great if you’re creating a home office or hobby space, without the weight and bulk of cast iron.

• Further reading: The best electric radiators

Garage and shed radiators at TradeRadiators.com

Once heating is sorted, your garage or shed becomes far more than just a storage space, it can be turned into a fully usable part of your home, whether that’s a home office, workshop, gym, hobby room or simply a place to relax. Adding effective heating doesn’t just improve comfort, it also unlocks the full potential of the space and allows you to use it all year round. 

At Trade Radiators, we offer an extensive range of high-quality electric radiators designed to suit garages, sheds, and garden rooms of all shapes and sizes. From simple, practical solutions to more design-led statement pieces, our collection combines performance, efficiency, and style to help you get the most out of your space.

With a wide choice of sizes, finishes, and radiator types available, it’s easy to find the perfect fit for your needs, so you can create a warm, comfortable environment you’ll actually want to spend time in.