Complete Barndominium Insulation Guide: 5 Types (2024)


Barndominiums (a cross between “barn” and “condominium”) are a combination of living and recreational spaces contained within a low-maintenance metal structure.

They’re renovated agricultural buildings or new structures designed in the rural style.

Either way, you must use insulation to make them habitable, reduce energy costs, and comply with the building codes before moving in.

Generally, agricultural buildings don’t have insulation, and barndominium kits don’t automatically include insulation in the package, mainly because different climate zones need different insulation thicknesses.

So, it’s up to you to have suitable insulation. Failure to get the insulation right will make your living space too hot or cold.

This article explains the importance of insulating your barndominium so you can live comfortably no matter how hot or cold the climate is.

Understanding Barndominium Insulation

How heat moves

Firstly, let’s understand how heat travels. There are three separate methods of heat flow:


Conduction is how heat moves through solid materials.

A good example is how a coffee cup’s outside surface gets hot to the touch when filled with hot coffee. The heat has traveled through the cup wall.


Convection is heat moving and circulating through fluid materials like gases and liquids.

Hot gases and liquids are lighter and less dense than cold ones, so they rise as warm air rises in a room, allowing cold, dense air to fall and take its place.


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Infrared heat radiation travels in a straight line from a radiant object like glowing coals or the sun. Radiant heat warms anything in its path or can be reflected.

Dark objects absorb radiant heat, while light-colored and reflective objects reflect the heat away.

How insulation works

Heat always tries to move from warmer to cooler areas until there is no longer a temperature difference. Therefore, heat moves from outside a house to inside during summer and from inside to outside during winter.

To maintain a comfortable temperature all year round, you must find a way to interrupt this heat flow. The solution is to use insulation or reflective barriers (they aren’t the same thing, and we’ll discuss these later ).

Insulation reduces or blocks the heat flow from one place to another. Remember that heat transfer can take place by convection, radiation, and conduction. So we must provide something to block each type.

Prevent convection heat loss by blocking gaps and holes in walls, ceiling, and floor spaces. However, you must also ensure that blocking these points doesn’t cause water condensation, which causes rust or rot depending on the materials.

Prevent conduction heat loss by placing a thermal barrier in the way. Surprisingly, one of the most efficient heat flow barriers is motionless gas, usually air.

Fiberglass and foam trap layers of air or air bubbles within themselves, preventing heat movement.

Window manufacturers use the same principle in double-glazing. They trap motionless, dry gas, or a vacuum, between two glass layers so heat cannot cross.

We can stop radiant heat by placing a reflective object in its path. However, create an air gap between it and other solid surfaces to prevent condensation.


Warm air holds more water vapor than cool air. So when warm air touches a cold surface, it rapidly cools and deposits the vapor onto the surface as water droplets.

If condensation continues, it causes rot and fungal growth, so we must remove or prevent condensation from forming.

Whenever we insulate or reflect heat, there’s a chance of condensation forming, so install heat barriers using the correct procedures, usually by professionals.


How effective insulation prevents heat flow is measured as thermal resistance or R-Value. High R-Values are good insulators, whereas low R-Values are poor insulators.

R-Values depend on several factors:

  • Insulation type
  • Thickness
  • Density

We’ll discuss these in more detail later.

The amount of insulation and R-Value you need to maintain a comfortable indoor temperature depends on your climate. For example, homes in Alaska need a higher R-Value than homes in Florida or Hawaii.

Furthermore, R-Value also depends on your home’s heating and cooling system, the part of the house you intend to insulate, and how much moisture is in the air.

Fortunately, the federal government has provided many online resources to help you determine the best methods to maintain your home’s temperature.

There is also a map to help determine your climate zone and estimate what R-Values you need. For more information about your climate zone and insulation, click the 2021 International Energy Conservation Code.

Choosing insulation

Many insulation types are available. But, to choose the right one, you need to know what part of your house you intend to insulate and what R-Value you want.

You might want to consider costs, ease of installation, and whether it’s a professional or DIY job. However, remember that with government funding, you’ll probably have to use a government-approved contractor.

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Generally, installing more insulation in layers increases the R-Value. But, as the thickness increases, its weight compresses the layers underneath, thus reducing the insulation’s effectiveness.

Professional contractors have the training to know when to stop adding layers, so trust their judgment on whether to switch to a different, possibly more expensive insulation material.

Then there’s the question of using a radiant barrier. (Remember radiation?)

Radiant barriers reflect the heat radiation away from your home rather than absorbing it. Therefore, materials such as this don’t have an R-Value as such. Instead, they reduce heat gain.

Generally, radiant barriers complement insulation and should be used together.

Insulation Materials

Many insulating materials are available, and you should determine which is best for your barndominium. Rigid foam boards or spray-on foam trap gas bubbles within the solidified foam.

In comparison, bulk materials like fiberglass, cellulose, and others trap layers of air between their fibers, reducing heat flow.

Benefits of Effective Insulation

You must design and install your barndominium’s insulation professionally for maximum effectiveness. Dry, motionless air is one of your barndominium’s best and most readily available materials to reduce heat transfer across exterior surfaces.

Typically, correctly selected insulation operates by trapping air within a matrix. In the same way, you feel warm in bed with layers of blankets.

Similarly, you’re wrapping your barndominium in a big, snug comforter.

Barndominium insulation

Correctly installed insulation has several benefits:

Noise reduction

As well as reducing heat loss, insulation prevents sound from entering your home.

Like thermal insulation, good acoustic insulation depends on the material thickness and how much air is trapped inside.

Vapor barrier

Some insulation types, like fiberglass batts and rigid foam sheets, provide a barrier against moisture-laden air.

Because barndominiums are primarily made from metal, they suffer from condensation, which eventually causes rust and other issues.

Reduced energy costs

Because barndominiums don’t have internal load-bearing walls, designers use large floor-to-roof spaces, with ceilings following the roof pitch. Therefore, there’s often little or no loft space below the main roof structure.

Convection causes hot air to rise into the vaulted ceilings away from where the heat is needed. Generally, heat escapes through the roof during the winter, while during the summer, the air in this space becomes too hot for comfort.

However, suppose you install high R-Value insulation between the ceiling and roof. In that case, you reduce the energy needed to maintain a stable temperature in your home during all seasons.

Assessing Insulation

All leading countries recognize the advantages of reducing domestic energy usage. Therefore, it’s unsurprising that the US building codes specify minimum home insulation specifications depending on your climate zone.

It’s essential to comply with these local laws, and a building code inspector will inspect your insulation for compliance. If you don’t comply, you must put things right and probably have a financial penalty too.

Ensure you know the local law and building codes required for insulation and vapor barriers and comply with them.

Regional climate and insulation requirements

The 2021 International Energy Conservation Code (IECC) splits the country into various climate zones with specific insulation requirements, given as R-Values.

From the document’s information, a professional can calculate the different insulation thicknesses in various parts of your barndominium.

Insulation audit

Although you can hire a professional to do a home energy audit, it’s also something you can sometimes do yourself.

Find air leaks

Look for holes that produce drafts and seal them. For example, baseboards and where the walls meet the ceiling.

Other places to look for drafts include:

  • Where plumbing and electrical cables penetrate walls, floors, and ceilings
  • Around faucets
  • Cracks in exterior mortar
  • Cracks in foundations and sidings
  • Check around door and window frames
  • Check where doors and windows fit into their frames

Use an appropriate material for sealing, such as mortar, DIY polyurethane foam, caulk, tape, and weather-strip. These places lose heat by convection.

So seal air gaps before insulating, and if the holes are around a heat-producing device, use a non-combustible sealant.


Sealing drafts is not the same as preventing ventilation. Any room that gets heat from burning fuel; natural gas, fuel oil, propane, wood, or coal, also needs adequate oxygen for combustion to reduce the amount of carbon monoxide produced.

Generally, each 1,000 Btu heat requires 1 sq. in. of vent opening. If you need help, contact a qualified and registered heating engineer.

Loft insulation

Check how much insulation you already have and compare this amount with the minimum building codes require.

Ensure the insulation depth doesn’t block any baffle vents that allow free air circulation. If you need help, ask an insulation professional.

Wall and floor insulation

Assessing this insulation is tricky if you don’t have the correct tools.

In this case, hire a professional insulation contractor to determine the insulation. They will probably use thermography (infrared scanning) to find heat leaks.

Vapor barrier

When inspecting the attic’s insulation, check for vapor barriers under the existing insulation.

These prevent condensation from causing problems.

5 Types of Barndominium Insulation

There are several insulation types used in a barndominium.

Leave it to a professional to determine the insulation for your circumstances.

Fiberglass Blanket or Batt

You see fiberglass blanket rolls in DIY stores. They often come with a vapor barrier already attached to one side.

Alternatively, batts are solid fiberglass slabs often used on walls and under floors.


  • Simple installation
  • Paper-backed fiberglass provides a vapor barrier
  • Requires simple installation tools
  • DIY friendly
  • Affordable
  • Used in new-build or retrofitted
  • Easy one-person installation


  • Slow installation
  • Produces glass dust, harmful if inhaled or in skin contact. Use a face mask, goggles, and gloves.


$1.00-$2.50/sq. ft.

Spray Foam

Spray foam is popular for new build projects as it’s fast.

However, it requires specialist equipment and a trained operative, so can be expensive.

Two types of spray foam suitable for use in barndominiums:

  • Open-cell foam – expands as it cures
  • Closed-cell foam – denser than open-cell and forms a vapor barrier when cured


  • Closed-cell foam doesn’t need additional vapor barriers
  • Speedy installation
  • Seals joints, fill gaps, and insulates simultaneously
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  • Needs specialist equipment & trained operatives, so not usually DIY friendly
  • Usually used in new-build projects as retrofit is complex


Prices vary significantly due to different types of foam. However, expect $1.50-$55.00/sq. ft.

Loose-fill or Blown-In Insulation

Option 1: Cellulose

Loose-fill insulation is shredded cellulose extracted from recycled paper. It’s cheap, easily used, and works better in colder climates.

Cellulose is sold in bales, fed into a shredder/hopper, and blown into cavities.

  • Inexpensive
  • Effective insulator
  • Easily installed
  • No fumes
  • Needs specialized equipment, but is DIY friendly
  • Messy installation
  • Produces fine cellulose dust, so use a dust mask.
  • Requires vapor barrier
  • Compacts under its weight, therefore reducing its R-Value
  • Needs chemical treatment against pests

$1.00-$2.00/sq. ft.

Option 2: Fiberglass

Loose fiberglass is also blown into cavities using a hopper.

It has a more insulating value by weight and doesn’t compress like cellulose.

  • Easily installed
  • Inexpensive
  • Doesn’t compact, so maintains its R-Value
  • DIY friendly
  • Needs specialized equipment, but is DIY friendly
  • Doesn’t need treatment against pests
  • Messy installation
  • Produces glass dust, so use a dust mask, goggles, and skin protection.
  • Needs an additional vapor barrier

$1.50-$2.50/sq. ft.

Radiant Barrier

Not an insulation but a highly reflective material, reducing heat radiation transmission. Used in conjunction with suitable insulation.

Typically, used under roof tiles or siding so heat doesn’t enter the barndominium structure.


  • Saves 5-10% on cooling costs
  • Impervious to moisture
  • Doesn’t support mold or bacteria growth
  • Non-toxic, without harmful dust
  • Helps keep your loft cooler
  • Reflects 90% of radiant heat away from your barndominium interior. Reduces temperature by up to 30⁰F.
  • In a new build project, install the radiant barrier as part of the roof deck


  • Only reduces radiation
  • Use it with insulation
  • Only effective in sunny climates
  • Keep in contact with an air space
  • Dust build-up may reduce efficiency
  • Not as efficient in colder climates


$0.30-$3.00/sq. ft.

Rigid Board

Also called sheet foam, it’s available in handy sizes to suit the required R-Value.


  • 4’x8’. sheets of 1″-4″ thick
  • Quick installation
  • Inexpensive
  • Easily cut with a handsaw
  • DIY friendly
  • No significant dust problem
  • Includes radiant barrier


  • With an R-Value of 6-24, sheet foam is one of the lowest insulation materials
  • Requires additional vapor barrier


$1.50-$3.50/sq. ft.

Best Practices for Installing Insulation

Each insulation type requires proper installation techniques to ensure they work efficiently and without problems.

There are several best practice techniques available to help your insulation work efficiently.

Keep materials clean and dry

If you store insulation in the open air, ensure it doesn’t become contaminated by dirt, concrete, or other foreign substances and protect them from rain.

Wet fiberglass and cellulose become soggy and don’t trap enough air within the matrix. Some foam products absorb moisture like a sponge, evaporating in-situ, damaging other materials, and encouraging mold and rot.

Careful handling

Insulation materials arrive on-site wrapped in waterproof packaging to keep them clean and dry. If mishandled, the pristine material becomes damaged.

Be careful when stacking to prevent compressed bottom layers and protect lightweight materials from strong winds. Manual handling equipment can easily damage foam slabs, so ensure they remain on a pallet until installation.


Cut rigid slabs carefully to fit cavities accurately.

Generally, using a handsaw for foam slabs and fiberglass batts won’t cause problems.


Before installation, seal all gaps and joints to prevent water, insects, and wind ingress.

Use various sealing methods depending on the insulation.

Follow instructions

Follow the manufacturer’s instructions to meet warranty conditions at all times.

Further information

For further information, look at this document from PassivHaus for handling and installing insulation good practices.

They’re a European modular housebuilding company, but the details are the same worldwide.

DIY vs. Professional Insulation Installation

Most installation methods are DIY friendly, even though some require specialist equipment.

Materials that produce dust require protective equipment like dust masks, eye, and skin protection. Furthermore, wear old clothes to prevent contamination.

You can only use an approved contractor with a government-backed construction loan for your barndominium project. Get advice from your lender before starting.

Before beginning the insulation project, assess what materials and equipment you need and whether it’s within your capabilities. If you have any doubts, hire a professional.

Although insulating your home yourself will cost significantly less, consider using a contractor, as they have significant advantages.

Using an insulation contractor

  • Some contractors specialize in barndominium insulation.
  • Choose a contractor experienced in the preferred insulation type.
  • Read as many reviews as you can.
  • Select bonded, insured companies that can operate in your state.
  • Use contractors trading longer than five years.
  • Get references for previous jobs. Speak to their referees about professionalism and whether they’ve seen energy savings since installation.
  • Ignore the lowest quote, as the quality may be poor. Use a mid-range quote.
  • Ask for a detailed quote using only approved materials.
  • Ensure you have a contract and warranty in writing before the project starts.
  • Never pay the total price upfront. Agree to a payment plan with the contractor.

Seasonal Insulation Tips

To get the best possible performance from your insulation, you must ensure it’s in good order. Generally, you can’t check hidden insulation’s condition, but a thermographic scan will highlight places where you’re losing heat.

At least once a year, check the following:

Drainage pipes

Although drainage pipes don’t continually hold water, so aren’t usually at risk.

In regions with extreme temperatures, they sometimes crack. Protect them from low temperatures and direct sunlight using proven materials and standard construction methods.

Water pipes

When water freezes, it expands, splitting pipes and faucet seals. When the ice thaws, water leaks from the splits, flooding your home and causing significant damage to your belongings and the barndominium’s structure.

Insulate the pipes properly so there’s no exposed surface. In areas with very low temperatures, you can install trace heating cables to prevent pipes from cooling below freezing point.

Attic or loft space

Heat rises through the barndominium and collects at the highest point, especially if you have open vaulted ceilings.

If ceilings were insulated correctly during the building phase, there shouldn’t be any problems now. But, if you can access the roof space, inspect corners and shallow areas where blown insulation may have settled incorrectly.

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Also, check for compressed fiberglass blankets, which will reduce the R-Value. Use DIY aerosol polyurethane foam to seal small cracks and fill hard-to-reach cavities.

Check the vapor barrier is intact, with no signs of condensation, rot, or fungal growth. Finally, don’t block any vents without discussing this with an expert.

Exterior Walls

The existing walls of your barndominium should already have insulation to comply with your area’s building codes.

Therefore, a thermal scan is all that necessary to ensure it’s operating correctly.

Weather-stripped Doors and Windows

All exterior doors and windows must have weather strips to prevent drafts and heat loss. Ensure weather-stripping is in good condition.

Otherwise, replace them. Check that window shutters open and close correctly, and create a weatherproof seal.

Double glazing

Double or triple-glazed windows are great for keeping the warmth indoors.

However, if there’s condensation or misting inside the glass unit, the seal has deteriorated, and they’re no longer working as intended. Replace the sealed window units with new ones.

Ceiling Insulation

Some properties have complex layouts and additions.

Check that every ceiling has insulation.


Floors open to the outside air, such as those above open crawlspaces or in contact with uninsulated foundations, need insulation.

Outdoor plumbing

Like indoor plumbing, exterior pipes, and faucets need protection too.

Generally, it’s easy to insulate external pipes and install frostproof faucets.

Air Leakage Points

Light switches and fixtures allow warm air into the wall cavity.

Seal them with aerosol foam.


Equip working flues with chimney caps to prevent downdrafts.

If you no longer use the chimney, seal the flue with balloons or plugs. Have a professional install an insulated liner for an old working chimney.

Eco-Friendly and Sustainable Insulation

If you prefer eco-friendly insulation, choose from several options from two distinct categories:

  • Natural insulation, made without using manmade chemicals. These won’t release toxins into your home and will biodegrade at the end of their lifespan. However, don’t use these in brick or block construction, nor cavities below the damproof course, as they will collect moisture.
  • Recycled insulation uses manmade materials, removing the need for end-of-life processing and using new resources.

Sheep wool

Wool is a sustainable resource and has useful insulating characteristics. It’s one of the best natural fibers, absorbing and releasing moisture while remaining dry.

Commercially, use sheep wool slabs like mineral wool.

  • Its thermal conductivity is similar to mineral wool.
  • Made from keratin, which reacts with and neutralizes air pollutants such as formaldehyde to improve indoor air quality.

Recycled Insulation

Recycled insulation includes some made from recycled PET, the plastic used in plastic bottles.

It’s impervious to water and has a similar thermal conductivity to mineral wool.


Straw insulates in the same way as wool or fiberglass slabs. It creates air pockets which form a thermal break.

Use straw as:

  • A structural insulating material, able to accept plaster
  • A roofing insulating material in the form of thatch
  • Infill into a timber-frame wall used as insulation and a base for plaster


More expensive than other eco-insulations, its thermal conductivity is comparable and is entirely sustainable.

The fibers come from hemp plant stalks and are used as a quilted insulation blanket or mixed with plaster or concrete for insulated construction material.


Cork is a naturally occurring tree bark with impressive thermal characteristics and damp resistance.

However, it suffers from over-harvesting.

Wood Fiber

This is a byproduct of the lumber and furniture-making industries. Wood fiber insulation is available as:

  • Wool-like rolls
  • Rigid boards
  • Semi-rigid boards


Typically, cellulose insulation is recycled paper treated with boric acid to prevent insect, rodent, and fungal infestation. It’s loose-blown into framed wall cavities.

Cellulose has good thermal conductivity making it one of the most economical insulations.


Typically made from recycled clothing. Like cellulose, it’s treated with boric acid to prevent infestation.

It’s available in rolls or as loose-blown. However, its thermal conductivity isn’t as good as mineral wool.

Troubleshooting and Common Issues

You need to know what can go wrong with insulation and how to fix them.

Over time, insulation installed in your attic may deteriorate. Age, environment, or lack of maintenance could cause problems. But, whatever it is, you must restore it to its original condition.

Inadequate Insulation

Installing insulation incorrectly can cause areas without insulation.

This results in condensation, accumulated moisture, sheltering pests, and high electricity bills from lost heat.


Top up or replace attic insulation.

Alternatively, hire a contractor. You’ll get a warranty too.

Uneven Attic Insulation

If insulation isn’t layered evenly across the attic floor, it will reduce its effectiveness and efficiency.


It can be challenging to get even-depth insulation. So, hire an insulation contractor. Then, the material is at the correct depth.

Blocked Attic Ventilation

Attics need good ventilation to reduce condensation and associated problems.

Installing insulation haphazardly can block vents, causing mold and fungal spores. This affects many people’s breathing, especially if inhaling it over long periods.


During installation, ensure the vents don’t become blocked and keep clear of insulation.

Compacted Insulation

Almost everyone uses their attics for storage.

However, don’t allow boxes to crush the insulation, removing air pockets and reducing its R-Value.


Remove heavy boxes from on top of the insulation.

If possible, place them on shelves or other attic storage solutions.

Pest Infestations

Because people don’t venture into an attic often, pests prefer to live in its relative shelter.

Attics with inadequate insulation and unfinished vents are ideal for rodents, birds, insects, and spiders.


If you notice pests in your attic, gaps in and around the vents and inadequate insulation will occur.

Fix these problems; if this doesn’t work, call a pest exterminator.

Ice Damming

Ice damming in colder climates can be severe.

In winter, snow thaws and subsequently refreezes into ice along the edge of the roof, which can cause damage to the roof’s structure.


One of the causes of ice damming is inadequate insulation.

Hire a specialist ice-dam removal contractor to fix the problem.


Whether your barndominium is a new-build kit or a renovated barn, you need insulation to save energy and prevent condensation issues.

Knowing which insulation to use for various parts of the structure and how to install them is a job only a contractor can do. Inadequate insulation isn’t only contrary to your local building codes. It also makes your barndominium’s inside temperature uncomfortable and increases energy costs.

You can use several online federal government resources to advise insulating your home. Furthermore, several state and federal grants or loans help with the cost.

Finally, when insulating your barndominium, research everything you can about the options and how to install insulation. When you’ve done this, you’ll have a home with a comfortable temperature that won’t cost a fortune to heat or cool. What are you waiting for?

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