A detached garage is a fantastic thing… until you need to think about heating it.

There’s nothing better than a fully seperated space for storage, working on projects, and of course storing cars. But being seperated from home means you often need an entirely seperate heating solution.

Thankfully there are some great options for heating a detached garage. Not just heating it well, but not costing too much in the process.

In this article, we’ll cover the best ways to heat a detached garage – including tips and advice to make the most of your heating system.

What’s The Best Way To Heat A Detached Garage?

Depending on the size of the detached garage and ventilation, you should opt for either a propane, oil, or infrared heater. If you’ve got good insulation and a free outlet, infrared is best for heating a section of a garage while an oil heater is best to heat the whole garage. If it’s a little drafty though, a propane heater with good ventilation is by far the most powerful detached garage heater.

That being said – there’s a lot more detail than that! Not to mention we haven’t covered the most important topic in this whole conversation.

Read on and let’s dive into the details about the best way to heat a detached garage.

You Need to Start with Insulation

While you may be tempted to skip this step and jump right into adding a heat source, don’t!

Insulation is relatively inexpensive, and it’s incredibly energy efficient. Meaning you will get your money back. It will work to keep your detached garage cooler in the summer and warmer in the winter. It works by creating a barrier against heat loss and gain wherever you add it.

Simply put, you will spend less to heat your garage because heat won’t escape past the insulation barrier.

The Best Types of Insulation for a Garage

Frankly, you can use any type of insulation you would use to heat your house.

Having said that, you may have more or less sensible options depending on whether you have a finished garage.

Fiberglass Insulation

If your garage is unfished—there is no drywall—and you have visible wall studs and ceiling joists, the best bet is likely fiberglass insulation. It’s not fun to work with, but it’s the most common choice for a garage. Not to mention most homes.

Cellulose Insulation

If your garage walls have been finished—they are drywalled—then you should consider cellulose. This type of insulation is used in pre-existing cavities. It’s manufactured from recycled newspaper and then treated with a fire retardant.

Strategically placed holes are made in the wall and the cellulose insulation is blown in with the use of a machine.

Rigid Foam Insulation

As the name suggests, these are rigid boards of insulation.

They come in 4 x 8-foot sheets and are available from ½ to 4 inches thick. These boards are a great option for insulating the garage door. Also, consider this for the floor if you’re planning on using your detached garage for additional living or office space. Lay the foam boards down, cover with a subfloor, then add your choice of flooring.

One last note on insulating your detached garage. I touched on it above, but it bears specific mention. Insulating the walls, ceiling, and floor—if necessary—of your space without dealing with the garage door as well is pointless. There are special kits you can buy for the job or you can just use the foam boards mentioned above.

Now let’s add heat!

What’s the Best Type of Heater for A Detached Garage?

Let me start off by saying the following will be somewhat subjective. Not because one type may be better than another, but depending on where you live, availability and popularity may play into what someone chooses. And availability and popularity may be based on the cost to run the heater, not how well it works.

With that in mind, here are the best heaters for your detached garage. Or even your attached garage.

Propane Heaters

Many people wonder if propane heaters are safe to use indoors, or more specifically in their garage. So let’s deal with that first.

Like any other potentially dangerous appliance, propane heaters are safe as long as they are used properly. A propane heater is no more dangerous than the furnace you have in your home, and you don’t even think twice about having one of those.

Here are a few safety tips:

  • Choose the appropriate size for your space
  • Make sure it carries an Underwriter’s Laboratory (UL)
  • It should have overheat protection and auto shut-off features
  • Install on a non-combustible surface
  • Never place anything on top of it
  • Read the manual!

Here is a resource that has a more extensive list of safety tips.

Propane Heater Benefits

  • They’re easy to install
  • Most models are portable
  • Affordable
  • Available in sizes that will heat a variety of spaces, large or small

Infrared or Radiant Heaters

Just so there isn’t any confusion, these are the same technology. Many people assume they are different types of heaters, but the only thing that’s different is the name.

Radiant or infrared heat works in the same way the rays from the sun work. Heat is pushed—or radiated—from the source out into the room. As long as it is placed within the distance that a manufacturer says the source will cover, everything within that vicinity will be heated.

There are several different styles of heaters, but the most popular in garages are ceiling mount units. They are out of the way and don’t take up any of your precious floor or wall space.

Radiant Heater Benefits

  • They heat quickly
  • Very quiet operation
  • Efficient
  • Can be ceiling mounted

Oil-Filled Space Heaters

If operating expenses are a concern, then this type of detached garage heater may be your best bet.  They use significantly less energy than the radiant technology mentioned above—and they’re typically cheaper to buy.

The technology behind them is a mix of thermal convection and radiant heating. They pull cooler air from around the unit, circulate it through the oil-filled fins, and then push the warmed air out.

There is a downside, though. These types of heaters will take the longest to heat up your space.

Oil-Filled Space Heaters Benefits

  • Less expensive to operate
  • They still put out heat even after they are turned off
  • Less expensive to purchase

How Can I Heat My Detached Garage Cheaply?

Of the options mentioned above, the cheapest heater to run will probably be an infrared heater, but if you want to heat the whole garage then an oil-filled space heater may be the better option.

Having said that, there are a few things you want to watch out for. Be sure the unit you want to buy is rated to cover the area you need it for. If you buy one that’s too large, it will use more energy and cost you more to operate. If you buy one too small, it won’t heat your space efficiently.

Whichever route you decided to go based on your own needs, make sure you take the first step of insulating your garage. It will cost you more upfront, but it will save you in the long run since your heater won’t need to work as long and as hard to keep your space warm.


If you live in a cold climate, adding heat to your detached garage is just good sense.

Even if you only use your garage to park your car in, heat is a protection for your battery and will lengthen its lifespan. And if you are using your garage as a work or living space—well, I likely don’t need to explain to you why heat is a good idea!

You can pick any of the above-mentioned types of heaters with confidence, knowing they will do the job you need them to do.

Thanks for stopping by.  While you’re here, why not check out some of our related posts below?