In our 55 years of experience optimising customers living space, we’ve learned a thing or two about garden office heating.

Keeping your garden office warm in the winter and cool in the summer is extremely important.

You’ll want access to a productive and optimally heated workspace that can be used 365 days a year.

Garden Office Heating Summary

For most people, the optimal office temperature is between 20 and 25 degrees celsius. 

Based on our experience, the best and most efficient way to achieve this temperature in a garden office is with an electric oil filled radiator, underfloor heating system or an air conditioning unit, depending on your budget.

In the rest of this article, we take a deeper dive into these heating methods and what type is best for you and your needs.

What is the optimal temperature for a garden office?

The perfect temperature for a productive workplace has been in contention for hundreds of years, with genuine stories of colleagues falling out over disagreements.

Not paying attention to this can have detrimental effects on productivity, having financial implications for businesses of all sizes.

We all, employers especially, need to take office room temperature more seriously.

Lucky for you, if you have a home garden office, you can optimise your perfect working temperature to your liking.

I know you’re only interested in keeping your garden office warm in the winter but listen to this; according to the BBC, “around 2% of office hours in the UK are wasted by battles for climate control, costing the economy more than £13 billion each year”.

Maintaining an optimal room temperature is vital for job satisfaction and maximising the hours in your working day.

Whether you run an online E-commerce business or a freelance graphic designer business, ensuring your garden office is perfectly heated is important.

From the findings of multiple studies, and our experience working in garden offices, the optimal temperature for an average work office – writing emails, making phone calls, creating content – is somewhere between 20 and 25 degrees celsius.

Factors affecting optimal workplace temperature

Optimal working temperature between 20 and 25 degrees will be suitable for the majority of the population.

However, there are a number of factors that affect optimal workplace temperature within and outside this range, including your personal preferences and genetic makeup. Here are a few of them factors:

  • Gender: Women reportedly work better in an environment that is 2-3 degrees warmer than men because they may have lower metabolic rates.
  • Weight: A person’s weight and body mass index can affect their perception to room temperatures. Typically, the heavier you are, the more warm you’ll feel, vice versa.
  • Age: The older you are the more reactive to colder temperatures you’ll be.

Of course, these are only general rules and may not apply to your situation. We recommend using trial and error to find your perfect workspace temperature.

Something to consider…

Your garden office should be properly built and insulated in the first place, so that it is warm in the winter and cool in the summer naturally.

At Garden Office Buildings, we use structural insulated panels (SIPs) in all of our garden offices.

They’re the best option for energy efficiency in our experience, consistently delivering lower U-values than a traditional timber build (the lower the U-value, the greater the insulative property of a material)

Garden Office Heating Methods

Now let’s get into the practical information that you need to efficiently heat your garden office to your optimal temperature.

There are a multitude of heating methods for a garden office but we’ve kept this list short and concise as we believe that these are the best methods for price, efficiency and running costs.

Electric Convection Heater

Arguably the most common type of portable heater you’ll see in the UK, the electric convector heater is a reliable and speedy way of heating any sized garden office all year round.

They rely on the circulation of air within a room, as air is blown over a heating element within the convection heater, and then re-circulated.

The average running cost per hour (based on standard meter and 2 kW heat output) is around 28p for an electric convection heater.

Pros Cons
Inexpensive to buy (£15 +) Air can become dry with long term use
Instant heat and will heat an average garden office with no problems Some may produce a slight humming noise
Timing options available Must avoid placing objects nearby
Free standing and wall mounted options  

Many garden office companies will provide an electric convection heater as standard. They don’t require installation and are narrow, lightweight and easy to move around.

Electric Oil-Filled Heater

Next up is the electric oil-filled heater. Back in the day, these types of heaters were heavy and bulky and commonly installed in basements.

Nowadays they’re portable, lighter, and usually come equipped with wheels for easy transportation.

They work by using an electric heating element submerged within the oil, which heats the oil and circulates it around the heater.

Some units have a setting that allows minimum and maximum temperatures to be set, so your room can maintain its ideal temperature.

The biggest benefit is that they use heat-trapping oil which means there’s no need to refill them. This also means that they retain their heat even after being switched off.

The average running cost per hour (on standard meter + 1.5 kW of heat output) is around 21p for an electric oil filled radiator, nearly a third cheaper than the electric convection heater.

There are many brands on the market but it doesn’t matter too much in our opinion. We recommend checking out amazon or Screwfix for a good range of oil-filled heaters.

Pros Cons
Inexpensive to buy (£30 +) Takes a bit longer than a convection heater to warm up a room
Oil never needs replacing Bulkier and heavier than a convection heater
Continues to stay warm after being turned off Limited style and colours available
Practically silent, as no fans are used  
Timing options available  
Doesn’t dry air out like a convection heater  

Overall, electric oil filled radiators are a solid option for any sized garden office. They’re cheap and the fact they don’t dry the air out as a convection heater does is a massive advantage over the electric convection heater.

Underfloor Heating

Now that we’ve covered both of the portable heating options, next we have a heating method that requires installation during the construction phase of a garden office.

More and more garden office suppliers are providing underfloor heating as an option, with some more expensive providers using it as standard.

It’s installed between the timber subfloor and the visible internal flooring inside the garden office, and typically uses an electric mesh element to heat the floor.

Underfloor heating is more expensive to install but gives you maximum control over timings and temperature limits, whilst also permitting maximum flexibility over furniture positioning as underfloor heating doesn’t take up any floor space.

It’s a more premium option, as it will heat a room much like traditional central heating does, but is obviously more pricey to install.

You’ll need to be certain during the design phase that you want to go ahead with this type of heating, as it’s a pain to fit at a later time.

Installation costs are roughly £60 to £90 + VAT per sq metre for supply and installation of electric underfloor heating.

Using this estimate, installation costs of underfloor heating costs for a medium-sized garden office of 10 sq metres will cost anywhere from £600 to £900 + VAT.

In London and South East England this will probably be a little more.

In terms of running costs, according to, a 10sq metre garden office will cost 11.81p an hour to run. This is obviously much cheaper than the previous two options, but it comes with a bigger initial cost.


Pros Cons
Low running costs Expensive to install (£500 +)
No physical footprint which gives you maximum flexibility over furniture positioning Maintenance can be complicated
A great long-term heating solution  
Full timing and temperature setting controls  

Air Conditioning (AC)

Finally, the trusty air conditioning unit. The biggest benefit here is that you have climate options for heating and cooling, so you only need to invest in one method of temperature control.

There are a few types of AC options available:

Portable AC Units

  • Cheapest AC option, starting at around £300 for a decent unit. Can be picked up from your local hardware store like Screwfix
  • Easy to move around your garden office for wherever you decide to sit
  • A window will need to be left open in order to vent the resultant heat
  • Tend to be a little noisier than installed units

Installed/Domestic AC Units

  • More expensive and must be installed by a registered gas engineer. Cost around £1,000 and above for an indoor unit in your garden office
  • Typically wall-mounted so they don’t take up any floor space
  • Like underfloor heating, it’s best to decide if you want one during the design phase, as AC unit installation requires making holes in walls.
  • These types of AC systems come in different levels of complexity, depending on the number of units that you require. For a typical garden office, you’ll need the simplest form, a single room application. This will consist of a single indoor unit and a single outdoor unit, perfect for a garden office sized space.

For both portable and installed systems, running costs can be difficult to quantify accurately as cooling requirements are not as specific as heating. However, the average indoor 2kW unit may cost you around 8p per hour to run.


Pros Cons
Heating and cooling in one Expensive to install (starting at £300 for portable unit and £1000 for installed system)
Improves air quality through filter system Installed units must be installed and maintained by a registered gas safe engineer
Consistent room temperature can easily be achieved through setting controls  
Wall mounted options take up no floor space, giving full flexibility over furniture positions  

Honourable Mentions

  • Electric Fan Heater
  • Infrared heater
  • Wood burner

Garden Office Cooling Methods

Heating a garden office in the colder months is typically the main concern that garden office owners have.

However, in the UK, there may be a few weeks of the year where we’re lucky enough to have temperatures of 20 degrees and above. During these times, your garden office may get a bit stuffy and hot, much like your main house does.

Now we are going to discuss different garden office cooling methods that you can use to keep your garden office cool on a hotter than average day.

Basic Electric Fan

Not much needs to be said about this type of cooling method. You probably already have one of these crammed under your bed or in the loft, ready for deployment once a year when it becomes unbearably hot at night.

They do a decent job of cooling a person down but aren’t particularly effective at keeping a whole room cool.

If you don’t have an electric fan already, don’t bother buying one and instead skip to our next suggestion.

Air Conditioning Unit

This is probably the best option for keeping a garden office cool in the summer and is superior to a basic electric fan.

Opening Doors and Windows (+ use blinds/curtains)

This is an obvious one, but you’d be surprised at how many people don’t simply open the doors and windows of their garden office during the summer.

Furthermore, if you are lucky enough to have south-facing windows in your garden office, consider investing in some good blinds/curtains to block the light coming through. This will significantly reduce the amount of heat that comes into the room.


As made clear in our introduction, we believe that the best and most economical way to achieve an optimal temperature in your garden office is through one of the following methods, depending on your budget:

  • Electric oil-filled radiator
  • Underfloor heating system
  • Air conditioning unit.

The latter two options are more expensive to install, but provide a more comfortable and reliable source of heat.

A basic electrical convection heater is also a decent contender as they are cheap and provide instant heat. However, the other options mentioned above, especially the latter two, are better for long term use.


These are all great methods for perfecting your garden office environment, however, your garden office should be built properly and insulated so that the use of these methods is minimized and your office is comfortable for most of the year without them.

If you’re keen to add as much value to your property as possible, then underfloor heating or air conditioning will be the most attractive to prospective buyers. We wrote more about that in this article.

All of our Garden Office Buildings come with underfloor heating as an optional extra, as we believe it is the best option if you’re serious about adding a year-round garden office to your home.