How to Insulate a Barn Conversion

insulate a barn conversion

Converting a barn is a great way to create a unique and beautiful home. However, barn conversions come with their own set of challenges – especially when it comes to insulation. Originally designed for agricultural purposes, barns aren’t built with human comfort in mind. This often leads to substantial heat loss if not properly addressed. Understanding how to effectively insulate your barn conversion is vital to creating a home that is comfortable to live in all year round.

Why is insulating a barn conversion so challenging?

Most barns were originally built for storage purposes or to house animals. Original doors and windows, often poorly fitted, are common culprits for letting heat escape and cold air enter. Additionally, some of the features we love about barns – their soaring ceilings and vast open spaces – can also be their Achilles’ heel in retaining heat. Warmth rises and easily escapes through inadequately insulated roofs.

Which parts of my barn conversion require insulation?

To comply with building regulations, you need to install the appropriate level of insulation across your barn conversion.

Barn roofs

Insulating a barn roof can be challenging. Often, barn roofs are removed to make necessary alterations, a process that can be both costly and time-consuming. Some homeowners opt to use spray-applied polyurethane foam instead. This foam can be sprayed directly onto the underside of roof tiles.

Vaulted ceilings

If your barn features vaulted ceilings and you intend to include them in your final design, you will likely need to place insulation between the rafters and potentially underneath them, if necessary.


Barn walls can vary from solid brick or stone to timber, each requiring different insulation strategies. For stone or brick walls without a cavity, insulation must be added internally to preserve the exterior look. This often involves installing a layer of insulation material directly onto the inner surfaces of the exterior walls. While some homeowners prefer the interior exposed brick or stone look, practicality may necessitate covering these surfaces with partition walls that better accommodate insulation materials.

Timber walls

Timber walls in barns are usually easier to handle. The existing timber cladding can be removed, allowing for the addition of insulation and a breathable damp-proof membrane before reapplying the original cladding. This process helps maintain the barn’s authentic character while significantly improving its thermal performance.


Insulating barn conversion floors typically involves excavating the existing floor to lay a damp-proof membrane and rigid insulation boards, which may be combined with underfloor heating for added comfort.


A lot of barns only have small windows, originally intended for ventilation purposes only. Many homeowners opt for large, double-glazed windows that not only minimise heat loss but also flood the space with natural light. Floor to ceiling windows are a popular choice for many barn conversions, as they work to modernise the building as well as having insulating benefits.

How can I insulate a barn conversion?

Here are some examples of ways you could insulate a barn conversion. Every barn conversion is unique, so it’s not a one-size-fits-all situation. You’ll need to work together with barn conversion specialists and the characteristics of your barn to find the best way to do the job.

Spray foam insulation

Ideal for barn conversions, spray foam provides excellent thermal performance and seals gaps and cracks effectively. It’s versatile enough to be applied to walls, roofs, and floors, accommodating the irregular surfaces and awkward nooks often found in barns.

Multifoil insulation

Used for internal wall insulation, these products reflect heat and create an air barrier to prevent moisture penetration. Often used alongside rigid board insulation.

Rigid foam boards

These are suitable for areas with flat surfaces and provide good thermal resistance. Easy to install, rigid foam boards are a straightforward solution for sections of your barn that are less irregular.

Additional things to consider before you insulate a barn conversion


Insulating a barn conversion involves ensuring good air quality in addition to keeping the cold out. Consider integrating systems to manage air flow efficiently throughout your barn conversion, preventing future issues of dampness and mould while retaining warmth within your space.

Compliance with building regulations

Any insulation you install in your barn conversion must meet specific building standards. This involves selecting the appropriate materials and installation techniques that achieve the required thermal performance without compromising the building’s character.

Barn conversion insulation made easy with Astrum Construction

The quality of your barn conversion insulation is the difference between a cold, drafty space or a warm and inviting home. Regardless of the insulation method you use, you must work together with the unique structure of your barn to maintain its original character.

Ready to take the next step in your barn conversion journey? As barn conversion specialists with over two decades of experience, we can help you with everything from restoration work on the structure of your barn to stylish finishing touches. Contact us to explore how we can tailor insulation solutions and breathe new life into your rustic retreat.

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