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Tiny House Insulation Options: What is the Best Insulation for a Tiny House?

Written by Amanda Emery | Dec 24, 2025 1:00:00 PM

The right insulation in your tiny house can make the structure more comfortable, and as energy-efficient and eco-friendly as the rest of your life.

You have many options when choosing the best insulation for your tiny home. Your choices include denim, foam board, fiberglass, and spray foam. Each has its own set of pros and cons, so it comes down to your needs.

RetroFoam of Michigan has insulated thousands of homes across Michigan’s Lower Peninsula, and some of those are tiny homes. We understand the want a homeowner has to reduce their carbon footprint, so we’re here to help.

In our continued efforts to educate homeowners, we have compiled a list of the most common tiny house insulation options. We will take a look at each insulation material and its pros and cons.

Key Points: Tiny House Insulation at a Glance

• The right insulation impacts comfort, energy efficiency, and sustainability in a tiny home, not just temperature control.
• Denim insulation is eco-friendly and non-toxic, but it's heavier and slow to dry if it gets wet.
• Foam board insulation offers moisture resistance and flexibility in thickness, but seams must be sealed carefully to prevent air leaks.
• Fiberglass insulation is budget-friendly and DIY-friendly, but it still allows air movement and loses effectiveness when wet.
• Closed cell spray foam provides both insulation and an air seal, making it a strong option for tiny homes with limited space.
• Cost, building codes, and long-term performance should all be weighed before choosing an insulation type.
• Not all insulation options are DIY-friendly, especially when air sealing and moisture control are critical.

Tiny House Insulation Options

There are so many options for one tiny house, but below we will discuss some of the more common options and what they offer.

Denim Tiny House Insulation

Blue jeans are more than a fashion choice; denim is also an insulating option.

Denim insulation is made from recycled textile fibers, formed into batts. The material is also a green option, as it doesn’t contain any chemical irritants, according to Tumbleweed Tiny House Company.  

Denim Insulation Pros:

  • Uses a renewable energy source in production.
  • Non-toxic.
  • Well-suited as a DIY project.

Denim Insulation Cons:

  • Twice the weight of fiberglass batts.
  • Hard to cut if it doesn’t fit perfectly in the cavity.
  • Takes a long time to dry out if it gets wet.

Foam Board Tiny House Insulation

Foam board insulation is a rigid panel that is made up of either polystyrene, polyisocyanurate, or polyurethane.

The boards come in a variety of thicknesses, lengths, and facings, which makes it easy to properly fit for your tiny house insulation project.

Foam Board Insulation Pros:

  • Expanded polystyrene board is the only foam board that doesn’t use HCFCs in its production.
  • Rigid foam board insulation is made to be water-resistant.
  • Foam board insulation can be installed as a DIY project in open cavities, so before you put the drywall up.

Foam Board Insulation Cons:

  • The joints between the boards must be taped or caulked to prevent airflow.
  • Polyisocyanurate foam boards can lose insulating ability over time.
  • The foam boards must be custom-cut to fit the cavity where they are installed.

Fiberglass Tiny House Insulation

Fiberglass insulation consists of extremely fine glass fibers and is available as blankets or batts for tiny home insulation.

Fiberglass as an insulator can slow the spread of air movement.

Fiberglass Insulation Pros:

  • Can be done as a DIY project.
  • Can be cheaper than other materials.
  • Suited for standard stud and joist placement that is free from obstructions.

Fiberglass Insulation Cons:

  • Still allows for air movement, which can lead to uncomfortable rooms and high energy bills.
  • Can trap allergens and dust.
  • If it gets wet, it loses insulating capabilities, which can lead to mold growth.

Spray Foam Tiny House Insulation

Closed cell spray foam is a spray-applied plastic that creates continuous insulation, as well as an air seal.

Closed cell is a great fit for tiny homes because it has a very low expansion rate.

Closed Cell Spray Foam Insulation Pros:

  • Creates an air seal.
  • Is energy efficient as it will keep your heating and cooling appliances from running constantly.
  • Doesn’t retain water.
  • Doesn’t serve as a catalyst if there is a fire.

Closed Cell Spray Foam Insulation Cons:

  • Is more expensive than other insulation options.
  • Some spray foam brands have an odor following installation that could last hours or, in some cases, days.
  • Not recommended as a DIY project.

Best Insulation for a Tiny House

When choosing the best insulation for your tiny house, there is more to consider than just the material alone.

The first thing to consider is whether your material options will meet code in your city, county, or state. Building insulation codes vary by place, so make sure you know what will and will not pass before you get started, and that you are on the same page as your building code inspector.

Your budget, expectations, and needs also play a huge role. It is important to weigh these factors before you make a final decision. You have decided on the tiny house life, so you should pick tiny house insulation that meets your needs and ideas.

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Frequently Asked Questions About Tiny House Insulation

What is the best insulation for a tiny house?

There isn't a one-size-fits-all answer.

The best insulation for a tiny house depends on your budget, local building codes, and performance expectations. Many tiny homeowners choose closed cell spray foam because it insulates and air seals in one step, which is especially valuable in small spaces.

Is spray foam insulation good for tiny homes?

Yes, spray foam insulation can be an excellent choice for tiny homes.

Closed cell spray foam has a low expansion rate, resists moisture, and creates an air seal that helps maintain consistent indoor temperatures and improve energy efficiency.

Can I insulate a tiny house myself?

Some insulation options, such as denim, fiberglass batts, and foam board, can be DIY-friendly when installed correctly.

Spray foam insulation, however, is not recommended as a DIY project due to the equipment, safety considerations, and precision required.

What insulation option is the most eco-friendly?

Denim insulation is often considered one of the most eco-friendly options because it's made from recycled textile fibers and contains no chemical irritants.

Spray foam can also be energy-efficient long-term by reducing heating and cooling demands.

Does tiny house insulation need to meet building code?

Yes.

Even tiny houses must meet local, county, or state building codes. Insulation requirements vary by location, so it's important to check code requirements and coordinate with your building inspector before choosing a material.

Why is air sealing important in a tiny house?

Tiny homes have less square footage, which means air leaks have a bigger impact on comfort and energy efficiency.

Insulation options that reduce air movement -- like spray foam -- can help prevent drafts, moisture issues, and uneven temperatures.