How to Heat a Pergola: 7 Safe Ways to Stay Warm Outdoors (UK Guide, 2026)

To heat a pergola safely, a wall or beam-mounted electric infrared heater is the best option for most UK gardens. It warms people directly rather than the air, has no open flame or fumes, and can be fitted under a wooden roof when you follow the maker's clearance guidance. Gas patio heaters and fire pits can work too, but only under an open-sided pergola with generous ventilation and overhead clearance. Below we compare all seven ways to stay warm, what each costs to run, and which are genuinely safe under cover.

In this article

• What is the safest way to heat a pergola?
• 7 ways to heat a pergola
• Pergola heater types compared
• How much does it cost to run a pergola heater?
• How to trap heat so it lasts
• Frequently asked questions

What is the safest way to heat a pergola?

The safest way to heat a pergola is a mounted electric infrared heater. Because it runs on electricity, there is no open flame and no carbon monoxide, which matters under a timber roof. Infrared warms objects and people directly instead of heating the air, so it works well in a semi-open structure where warm air would otherwise drift away. Choose an IP-rated (weatherproof) model, fix it to a post or rafter above head height, and keep the clearances the manufacturer lists.

Anything with a flame needs more care. Gas patio heaters and fire pits give off carbon monoxide and need real ventilation, so they belong under an open-sided pergola, never a fully screened or enclosed one. As a rule, keep any flame source at least 3 feet from combustible materials such as timber posts, cushions and fabrics, and follow the clearance in the product manual.

7 ways to heat a pergola

Here are the main options, from the easiest and safest to the ones that need the most caution.

1. Mounted electric infrared heater (best overall)

Fixed to a beam or post, an infrared heater delivers instant, directional warmth to the seating area below. No fumes, no refuelling, no flame. A 2kW unit comfortably covers roughly 3m of seating, which suits an Essentials 3x3m pergola. This is the option we recommend for wooden and covered pergolas.

2. Freestanding electric infrared heater

A portable, stand-mounted version of the above. Slightly less tidy than a fixed unit and it takes floor space, but you can move it to follow the group and take it under cover when not in use. Still flame-free and safe near timber.

3. Gas patio heater

The classic mushroom or pyramid heater throws out a lot of warmth and needs no wiring, which is handy for a pergola with no power run to it. The trade-offs: it burns LPG, so it produces carbon monoxide and needs ventilation, and it needs clearance of roughly 2 to 3 feet from the roof and walls (more if those are combustible). Use it only under an open-sided pergola, never a closed-in one.

4. Chiminea or wood-burning fire pit

Lovely for ambience, but the strictest on safety. Sparks, smoke and intense rising heat mean you want open sides and generous overhead clearance, typically 6 feet or more above the flame, and ideally a spark guard. Keep it well away from timber and soft furnishings. Under a low or partly closed pergola, skip it.

5. Bioethanol burner

A real flame with a key advantage: bioethanol gives off no carbon monoxide, so it copes far better in a sheltered spot than gas or wood. Output is gentle and it is more about atmosphere than blasting heat, but it is a tidy, flueless option for a table or corner.

6. Electric-heated furniture and accessories

Heated cushions, throws and even under-table heaters take the edge off without warming the whole space. Cheap to run and completely flame-free, they pair well with an infrared heater on the coldest evenings.

7. Trap the heat you already have

The cheapest heating is the warmth you keep. A solid or louvred roof stops warm air escaping straight up, and side screens or panels block the wind that steals it. Add an outdoor rug and blankets and a modest heater will do far more work. More on this below.

Pergola heater types compared

Use this to match a heater to your pergola and how enclosed it is.

Heater type	Safe under a wooden roof?	Warmth style	Running cost	Best for
Mounted electric infrared	Yes, with clearance	Instant, directional	Low to medium	Covered and wooden pergolas
Freestanding electric infrared	Yes	Directional, movable	Low to medium	Flexible seating layouts
Gas patio heater	Open sides only, needs clearance	High output, ambient	Medium	Open pergolas with no power
Chiminea or wood fire pit	Open sides, 6ft+ clearance	Radiant, ambience	Low (fuel)	Open, tall structures
Bioethanol burner	Yes, no carbon monoxide	Gentle, ambience	Medium (fuel)	Atmosphere on a table
Heated cushions and throws	Yes	Personal, contact	Very low	Topping up on cold nights

How much does it cost to run a pergola heater?

An electric infrared heater is cheaper to run than most people expect, because it warms bodies directly rather than wasting energy on the air. At a UK electricity price of roughly 30 to 35p per kWh in 2026, a 2kW infrared heater costs about 60 to 70p per hour at full power. In practice, models with a thermostat or lower heat settings often average closer to 40 to 55p per hour, and a smaller 1.5kW unit less again.

Gas works out somewhere similar per hour depending on LPG prices, but you carry and store bottles. Wood and bioethanol are priced by the fuel you burn rather than a meter. For most gardens, a thermostatic infrared heater used only while you are sitting out is the most controllable and lowest-fuss choice.

How to trap heat so it lasts

Whatever heater you choose, the structure does half the work. Warm air rises and wind carries it off, so a pergola that slows both keeps you comfortable for longer on less power.

• Add a roof. A solid, slatted or louvred roof stops heat escaping straight up and keeps rain off, which matters as much as warmth in a British autumn.
• Fit side panels or screens. Blocking the prevailing wind on one or two sides makes the biggest difference of all, and doubles as privacy.
• Zone the seating. Pull furniture together under the heater rather than spreading it to the edges.
• Layer the soft touches. An outdoor rug, cushions and a basket of blankets let a modest heater feel far warmer.

If you are still planning your structure, it is worth choosing one that already includes a roof and the option of screened sides. Our pergola bundle guide walks through the themes and sizes, and the hot tub pergola guide covers screening a spa. For evening warmth, pair your heating with soft light from our pergola lighting ideas.

Frequently asked questions

Can you put a patio heater under a pergola?

Yes. Electric infrared heaters are the safest because they have no flame or fumes and can be mounted under a wooden roof with the maker's clearance. Gas patio heaters can be used too, but only under an open-sided pergola with good ventilation and clearance from the roof, as they give off carbon monoxide.

What is the safest heater for a wooden pergola?

A wall or beam-mounted electric infrared heater. It produces no carbon monoxide and no open flame, warms people directly, and stays clear of timber when fitted at the recommended height. Look for an IP-rated weatherproof model.

How much does it cost to run an electric patio heater?

At around 30 to 35p per kWh in 2026, a 2kW infrared heater costs roughly 60 to 70p per hour at full power, and often 40 to 55p per hour with a thermostat or lower setting. Because infrared warms bodies rather than air, you get more comfort per unit than fan or convection heaters outdoors.

Can you have a fire pit under a pergola?

Only with real caution. A wood-burning fire pit or chiminea needs open sides and generous overhead clearance, usually 6 feet or more above the flame, plus a spark guard and at least 3 feet from any timber or fabric. Never use gas or charcoal fires in an enclosed or fully screened pergola because of carbon monoxide. Bioethanol is the safest flame option as it gives off no carbon monoxide.

Do pergola side panels help keep heat in?

Yes, significantly. Blocking wind on one or two sides is the single biggest thing you can do to hold warmth, because moving air strips heat away fastest. Panels and screens also add privacy and shelter from rain.

What size heater do I need for a pergola?

As a guide, a 2kW infrared heater comfortably covers about 3m of seating, which suits a 3x3m pergola. For a larger 4x3m structure, use a higher-output unit or a second heater to cover the full area evenly.