Insulated Cabin Advantages – Why You Need an Insulated Log Cabin

We’ve already done a post breaking down all the benefits of owning a garden log cabin. Still, from log cabin owners and people looking to buy one, we keep hearing the same question.

Do I need to insulate a log cabin?

So we’re going to put it to bed once and for all and break down the importance of insulation. Below, we’ll go through the benefits of insulating a garden cabin, how to insulate one, and whether or not it’s worth doing.

All that and more after the jump!


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Key takeaways:

  • In a traditional log cabin, the logs are the insulation
  • You need to insulate every point of heat loss in your building’s thermal envelope
  • Insulating your log cabin starts with a good base and flooring
  • Insulating a garden cabin might cost a bit more up front but it can save you money in the long term
  • Insulating your cabin is a good idea if you use it year-round or as a home office
log cabin in the woods meme
Credit: Pinterest

Why buy a log cabin?

A garden log cabin can be whatever you want it to be. It can be a place for work, for working out, or simply to relax. Plus, being out in the garden and sunshine could even positively affect your physical and mental well-being.

Log cabins make for energy-efficient garden buildings. The timber in a log cabin acts as a natural insulator with thermal properties which slows heat transfer between the interior and cold temperatures outside. Timber’s thermal mass varies with log thickness but can reduce heating and energy costs in your choice of garden cabin.

And a garden log cabin can be the perfect place for a gym, home office, or little salon. This is especially true if you do want to use your garden cabin year-round. If that’s the case, then keeping it warm in winter and cool in summer is something log cabins excel at.

This is because the wood itself is a natural insulator. Not only that, direct light from the sun can actually heat your log cabin (somewhat).

This means that:

  • Wood gets warmed by sunlight
  • Wood retains warmth well
  • Wood insulates your log cabin’s interior temperature against the cold
  • Wood slowly releases warmth due its thermal mass

Now, granted, even thick logs aren’t enough to fend off harsh winter temperatures alone. But you’re probably not looking at a ‘proper’ log cabin like in the movies – dusted with snow and made from freshly felled trees.

So how do you get those insulation properties without using 50mm-thick logs?

blue log cabin reverse apex roof with snow falling
Log cabins – great for year round use. @northinglikehome/Instagram.

Insulated Garden Cabin

As we say, chances are you probably don’t live in the arctic circle. So you probably are looking at a range of reasonably priced log cabins.

Still, you might be wondering – why insulate a garden cabin? After all, it rarely snows in England, and the weather isn’t that bad. (Yeah, right!).

Well, even for the inclement weather and temperatures that we face, insulating your log cabin can help you get the most out of it.

Insulating a garden cabin can:

  • Allow for efficient year-round heat exchange
  • Keep your log cabin warm in winter and cool in summer
  • Boost your log cabin’s usability (and potentially even value!)

So if you want a warm and cosy garden building for winter, it’s worth considering. If (like so many of us) you’ve transitioned to working from home and you don’t want to freeze, insulation might be the answer.

Why Insulate a Log Cabin?

To explain objectively why anyone might want to insulate a log cabin, we’re going to have to get a bit technical.

So bear with us; we’ll go slowly.

For a start, a wooden log cabin will naturally contract and expand slightly with climate changes throughout the year. So your best bet is to start with a log cabin made from tongue and groove panels. They offer a water- and airtight seal with enough room to accommodate expansion without warping or splitting.

Next, by insulating a log cabin, you could reduce the energy consumption you spend heating it. In turn, you’ll give off a smaller carbon footprint. (And probably get a smaller utility bill in the long run).

But the main reason you’d want to insulate your garden cabin is to because of something we call the thermal envelope.

thermal envelope and heat loss circular graph
Credit: Tuin

Thermal Envelope

The thermal envelope is everything about your building that shields it from the outdoors. This includes:

  • Vapour membranes
  • Walls and roof assemblies
  • Insulation (roofing and flooring)
  • Window glazing
  • Caulking

Basically, anything that aims to stop heat from moving from your garden cabin to outside. All these elements make up the thermal envelope.

So why is insulation so important?

Well, various studies have shown that:

Walls, windows, and gapsAccount for around 35% of heat loss
Floors Account for about 10% of heat disappearing
Roof and floors combinedAccount for as high as 70% of heat loss in your cabin

So are you doing anything to combat that? 

If not, then at best, you might be a bit chilly. At worst, you could be pouring money down the drain on heating or even putting clients off from coming to your home office.

But how do you figure out a suitable level of insulation to combat this? Well, this is where it gets technical. It’s all down to the R- and U-value of your outdoor garden building.

R-VALUEIs a measurement of heat flow resistance through a given surface (like wood).
Once you have your R-value, you can work out your U-value.
The higher a buildings R-value, the better.
U-VALUEIs a measurement of heat loss in watts when the temperature outside your building is at least one degree lower.
Your U-value will take into account the sum of certain parts. For example, your double-glazing’s U-value will account for glass and air.
In this case, the lower your U-value the better.

Ok, so you want a high R-value and low U-value in garden cabin. But what does that really mean?

R-value is the thermal resistance properties of your building’s envelope materials (like walls and insulation).

U-value is the insulating performance of elements like glass.

So you want thick or insulated walls to retain heat in winter and double-glazed windows in your log cabin to let it out gradually in summer.

Take a look at the table below for R- and U-values by log thickness.

Realistically, we wouldn’t worry about trying to work out your cabin’s values too much. Simply put, for a better energy rating in your log cabin, you want to slow down the escape of heat through surfaces.

In general, insulating your log cabin can be a one-time outlay that improves practicality without compromising on aesthetics. So how do you go about doing it?


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How to insulate a log cabin

If you can’t find a ready-insulated garden log cabin you could always check if your supplier sells insulation kits.

Below, we’ll break down into section what this entails for insulating each part of your cabin’s thermal envelope.

But an insulation kit (depending on how comprehensive) might include:

  • Stanley knife for cutting
  • Foil tape to cover gaps and joins
  • Foil-backed insulation rolls
  • Heavy-duty staple gun for application
  • Kingspan or Celotex insulation boards
  • Vapour or dampproof membrane
  • Fibreglass rolls or batts 

How to insulate a log cabin roof

We’ve written before about how to damp proof and insulate a shed. A lot of these general rules will apply to your log cabin also.

But the reason your log cabin’s roof is such a problem area is that hot air rises. And while timber has a high thermal mass, heat will still dissipate quicker in an area with a bigger heat difference.  

So to insulate a log cabin roof:

  • Opt for tongue and groove roof cladding for a tight seal
  • Lay a vapour barrier
  • Create a roof batten frame to hold insulation in place
  • Cut and fit insulation boards
  • Seal gaps with insulation tape
  • Place and fix roof cladding over insulation boards
  • Affix roofing: shingles, felt, or EPDM (a waterproof rubber polymer sheet)

You may have to adjust this if you still want visible trusses in your log cabin.

timber log cabin with double glass doors on a wood base
Credit: Nicholas Duggan

How to insulate a log cabin floor

Our log cabins floors are made of tongue and groove boards that slot together and are nailed to wooden floor joists.

This creates a thermal barrier. But, between your flooring and the ground, there are still opportunities for significant heat loss. This is because the ground is essentially infinite. So it can keep absorbing heat away from your garden cabin.

You can slow this process by building your log cabin on a concrete base (which also has a high thermal mass). However, this is more costly than a typical wooden sub-floor.

So instead, think about laying a damp-proof membrane beneath your log cabin. This will help to stop rising damp and be the first building block in insulating your floor.

On top of that, lay your timber sub-floor with a gap to allow for airflow. However, in the gaps between your floor joists, you might think about laying more Celotex insulation sheets.

Cut them to size so that they fit flush with no gaps. Then seal the joins between sheets with foil insulation tape. Make sure there’s no ground contact and then either screw into or glue the Celotex.

Once you’ve properly insulated your log cabin floor you can help reduce heat transfer by laying carpet or rugs. This will all help to combat heat transfer to the ground, which is a massive heat drain.

Celotex insulation boards in between shed wall studs
Credit: Southern Timber

How to insulate a log cabin’s walls

Anywhere where there is a gap in your log cabin ideally needs to be insulated. Of course, this is more likely with ‘proper’ traditional log cabins out in the wilderness.

For example, Garden Buildings Direct’s log cabins use tongue and groove panels to create a tight seal. Any gaps around your garden cabin’s door/s or window/s should be sealed, though.

To do this, use an expanding insulation foam or caulk around the frames. You can also reduce heat egress by opting for double glazing on your log cabin. 

You’ll also see the benefits of double glazing in the summertime – when your log cabin doesn’t heat up like a greenhouse! Make sure to also use a draught excluder at the base of your door frame. (Even adding curtains can help to insulate your log cabin!).

As for the walls, you can:

  • Check whether you need a vapour membrane:

    Does my shed need a vapour barrier Garden Buildings Direct infographic with three tiles for different sheds and climates with icons and arrows regarding air flow, insulation, and vapour barriers
    Use this infographic to decide if your wooden shed needs a vapour barrier.

  • Use fibreglass or natural wool batts or foil-backed insulation roll
  • Fill the cavities in between your wall studs
  • Cover with MDF boards or plasterboard nailed to your studs

How to heat a log cabin

Now, depending on where you live or even just how cold you get, you still might want to heat your log cabin. This should be part of your bigger plan to insulate your cabin rather than a last-ditch attempt.

This is because heating alone will inevitably cost you more over time than the initial outlay to insulate your log cabin. And if you don’t insulate it, it’s a bit like pushing water uphill.

You’ll be creating a greater heat differential between your log cabin’s inside and outside. On top of that, you won’t have anything to regulate this temperature.

Check out this post if you want to learn more about installing utilities in your log cabin. Running something like a tubular heater or low-energy radiator might be a good idea.

Insulated Cabin Advantages: Key Takeaways

If you’ve done all that, you might be thinking you could start to live in a log cabin. And you wouldn’t be far wrong.

Insulating your log cabin can help you make the most of it with year-round use. By regulating your garden cabin’s interior temperature, you can reduce heat loss and potentially save yourself heating costs.

To recap:

Insulated cabin = Higher thermal density

On its own, wood has impressive insulating properties. As an insulator, it prevents heat transfer between your log cabin’s interior and the external environment. This means that when the temperature outside dips, the heat from the interior of the insulated cabin remains stable.

That ultimately means a warmer log cabin even when it’s cold out.

On the other hand, wood also has a high thermal density. And the thicker the timber, the better it retains heat itself. Adding to your log cabin roof, flooring, and walls with insulation only increases its R-value.  

Log cabins in general are a healthy space

If you feel like you need to get away from the family or work without going away, an outdoor building is a perfect getaway.

Or, if you want to add value to your property, an extra room, and a new space to hang out with your family, it fits that bill too.

If you run a home business or work from home, you don’t want to be freezing in winter and sweating in summer. Simply insulating your log cabin can help with that. And an outdoor building, in general, can get you out into the garden and sunlight and give you a bit of peace!

Insulating your log cabin is cost-efficient 

Insulating a log cabin is energy-efficient and by default cost-efficient too.

An insulated log cabin is cheaper to maintain and won’t sting you for as high an energy bill. Heating a log cabin can be a losing game if you don’t have a proper base or floor insulation. That’s because the earth is a massive heat drain and will draw heat away from your cabin.

BillyOh Outpost Log Cabin insulation specs infogrpahic
BillyOh Outpost Specs

An insulated cabin means less humidity

If you’re storing things like gym equipment or electronics in your log cabin, the last thing you want is moisture. And that’s exactly what humidity leaves behind.

So instead of allowing your log cabin to turn into a sweatbox in summer, think about insulating it. Small hacks like adding double-glazing or a draught excluder can help to regulate interior and exterior temperature.

This makes it harder for condensation to form, which can be a problem with wooden structures in hotter weather.

Top tip: We suggest investing a little extra to add roof gutters. Not only are they easy to install, but they also do a great job in keeping your log cabin dry, ensuring it’ll last longer.

Should I Insulate My Log Cabin?

Hopefully, this guide has given you even food for thought to come up with an answer to that question.

But just to reiterate:

  • If you’re planning to use your log cabin year around
  • If you’re storing valuables in your garden cabin
  • If your log cabin’s timber isn’t thick enough to properly insulate it
  • If you want to add value to your log cabin
  • If you intend to have people stay over in your log cabin
  • And if you just don’t like being cold!

Then the answer to that question is probably yes. But it’s not a necessity – you could always save yourself some trouble and buy an insulated log cabin.

Just make sure to follow this guide and add to all areas of your garden cabin’s heat envelope. Insulate your floors, walls, and roof. Then, caulk and seal where necessary and install rugs, curtains, and a draught excluder.

And if you want to know a bit more about log cabins, check out our advanced guide here.

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FAQS

An insulated log cabin will stay warmer in winter and cooler in summer. This is because the insulation will increase your building’s thermal density, raising its R-value. This means less heat will escape in winter but also that your garden cabin’s inside temperature will be regulated.

Yes - log cabins can be insulated at all heat loss points in your garden building’s thermal envelope. These points include flooring, walls, roof, and door and window frames. Start by raising your log cabin on a suitable base off the ground to protect from rising damp.

 

  • Install Celotex insulation boards between your floor joists and roof trusses.
  • Line walls with foil-backed insulation roll and cover with MDF or plasterboard.
  • Then caulk or use expanding foam around any gaps in your window frame.
  • Finish with a draught excluder for your door and think about installing low-level ambient heating.

Generally, log cabins will fall under ‘permitted development’ in your garden, depending on their size and use. This may change if the proposed cabin exceeds 50% of your garden or is intended as a permanent living quarter. For more information - see this guide.

This will depend largely on your budget and how necessary insulating your log cabin is for you. For example, if you live in a colder climate or use your log cabin year-round as an office, your need increases.

 

The two biggest areas of your cabin’s thermal envelope to cover are the floor and the roof. Build a suitable base for your log cabin and raise it off the ground, which acts as a heat drain. Celotex or Kingspan boards are highly recommended for flooring insulation. You can also replicate this method for your roof.

 

If you want, less critical insulating steps might be to install double-glazing. Or, cheaper alternatives include laying carpet or rugs and installing things like curtains, a tubular heater, and a draught excluder. Alternatively, you could buy a pre-insulated log cabin.