--- title: "Insulation boards: types and benefits" description: "Insulation board types and benefits: learn about PIR, XPS, and EPS boards, their thermal conductivity (around 0.022 W/mK for PIR)." url: "https://www.fuseenergy.com/blog/insulation-board" updated: "2026-10-17" --- # Insulation boards: types and benefits Insulation boards are your home's first step towards energy abundance and unwavering comfort, laying the groundwork for a truly energy-empowered property. For homeowners, understanding these materials is key to making informed decisions that improve energy efficiency and reduce long-term costs. This guide breaks down the types, applications, and benefits of insulation boards, helping you create a more comfortable and efficient home. Considering insulation to boost your home's energy efficiency? Fuse Energy helps you make the most of your energy with clear pricing and smart tools. Click [here](https://www.fuseenergy.com/app/boarding/premises) to see how easy it is to switch. ## Understanding insulation boards ### What is an insulation board? An insulation board is a rigid or semi-rigid panel designed to reduce heat transfer through a building's walls, floors, and roofs. These boards create a thermal barrier, slowing the movement of heat between the inside and outside of a property. They are typically made from materials like polyisocyanurate (PIR), extruded polystyrene (XPS), or expanded polystyrene (EPS), each offering distinct properties for various applications. ### Why insulate your home? Insulating your home is a proactive step towards greater energy efficiency and comfort. A well-insulated property maintains a more stable indoor temperature, reducing the need for constant heating or cooling. This directly translates to lower energy consumption and smaller bills. Effective insulation also enhances comfort by eliminating cold spots and draughts, making your living spaces more enjoyable year-round. By optimising your home's thermal envelope, you're embracing a future where energy is abundant and less of a daily concern. ## Types of insulation boards ### PIR insulation boards Polyisocyanurate (PIR) insulation boards are a popular choice due to their excellent thermal performance. These rigid foam boards are made from polyisocyanurate and often feature foil facings. PIR insulation boards typically offer a thermal conductivity (lambda value) of around 0.022 W/mK, making them highly efficient. This low lambda value means they can achieve significant thermal resistance with less thickness compared to many other insulation materials. They are widely used in various applications, including pitched and flat roofs, internal and external walls, and floors. Common brands include Kingspan and Celotex. ### XPS and EPS insulation boards Extruded polystyrene (XPS) and expanded polystyrene (EPS) boards are other common types of rigid insulation. * **XPS insulation boards:** These boards are known for their closed-cell structure, which provides excellent moisture resistance and high compressive strength. This makes XPS ideal for applications where moisture is a concern, such as inverted roofs, basements, and floor insulation. * **EPS insulation boards:** EPS boards are a more cost-effective option, characterised by their lightweight, open-cell structure. While not as moisture-resistant as XPS, they still offer good thermal performance and are commonly used in cavity walls, floors, and external wall insulation systems. ### Other insulation materials While PIR, XPS, and EPS boards are prevalent, other insulation materials exist. These include mineral wool (rock wool and glass wool), which is non-combustible and offers good acoustic properties, and natural fibres like sheep's wool or wood fibre, chosen for their environmental benefits. However, for rigid board applications, PIR, XPS, and EPS remain the primary choices for their balance of performance, cost, and ease of installation. ## Key considerations for selecting insulation boards Choosing the right insulation board involves balancing thermal performance, regulatory compliance, and environmental factors. ### Thermal performance and u-values Thermal performance is measured by a material's thermal conductivity (lambda value) and a building element's U-value. The lambda value (W/mK) indicates how well a material conducts heat; a lower value means better insulation. The U-value (W/m²K) measures the overall rate of heat transfer through a complete building element like a wall or roof. A lower U-value indicates better insulation performance. The UK government's Building Regulations Part L sets minimum U-value requirements for different building elements, which insulation boards help achieve. For new constructions, these can be as low as 0.11 W/m²K for roofs and 0.18 W/m²K for walls and floors. When renovating, the requirements are slightly less stringent but still aim for significant improvements in energy efficiency. > **What is a U-value?** > > A U-value measures how easily heat passes through a complete building element, such as a wall, roof, or floor. Expressed in W/m²K, a lower U-value indicates better insulation, meaning less heat escapes through that part of the building. It accounts for all layers in the construction, not just the insulation material itself. ### Fire safety and building regulations Compliance with UK Building Regulations, particularly Approved Document B (Fire Safety), is crucial when selecting insulation materials. Approved Document B provides guidance on fire safety requirements, covering aspects like internal and external fire spread, and means of escape. Insulation materials must meet specific fire resistance and surface spread of flame characteristics, especially when exposed on walls and ceilings. For certain applications, such as in high-rise buildings, strict fire safety standards apply to insulation materials. It is essential to consult these regulations to ensure chosen materials are appropriate for the intended use and building type. ### Moisture resistance and durability Moisture resistance is a critical factor, particularly in areas prone to dampness or condensation. Using a non-water-resistant board in a damp environment can compromise its effectiveness and lead to issues like mould or structural damage. Materials like XPS offer superior moisture resistance due to their closed-cell structure. Durability ensures the insulation maintains its performance over time, resisting degradation from environmental factors or physical stress. Considering the longevity and resilience of the chosen insulation board is vital for a lasting, effective thermal envelope. ## Applications and installation best practices Proper installation is as crucial as selecting the right insulation board. Incorrect installation can lead to thermal bridges, gaps, or moisture ingress, significantly reducing effectiveness. ### Wall insulation Insulation boards can be used for both internal and external wall insulation. * **Internal wall insulation (IWI):** Boards are fixed to the interior face of external walls. This is often preferred for solid wall properties where external changes are not permitted or desired. * **External wall insulation (EWI):** Boards are applied to the exterior of a building, then rendered or clad. EWI can significantly improve thermal performance and protect the building fabric, but may require planning permission. ### Floor and roof insulation Insulation boards are also highly effective in floors and roofs. * **Floor insulation:** For solid ground floors, boards are typically laid over the concrete slab before the screed. For suspended timber floors, they can be fitted between joists or on top of the floorboards. * **Roof insulation:** In pitched roofs, boards can be installed between or over rafters. For flat roofs, they are often laid above the roof deck. Current standards require U-values of 0.15 W/m²K or better for pitched roofs and 0.18 W/m²K for flat roofs. ### Avoiding thermal bridging Thermal bridging occurs when there's a break in the insulation layer, allowing heat to bypass the insulating material. This can happen at junctions between building elements, around windows, or where structural components penetrate the insulation. To avoid this, ensure continuous insulation layers, meticulously seal all gaps and joints with appropriate tapes or foams, and consider using thermal breaks where necessary. Careful planning and execution during installation are essential to prevent these weak points in your home's thermal envelope. ## The long-term benefits of insulating your home Investing in insulation boards offers enduring advantages that extend beyond immediate energy savings. ### Reducing energy bills One of the most immediate and tangible benefits of effective insulation is the reduction in energy bills. By minimising heat loss, your heating system doesn't have to work as hard, consuming less fuel. The average UK home uses around 9,500 kWh of gas per year for heating, which can be significantly reduced with effective insulation. This reduction in energy demand means you're getting more out of every kilowatt-hour, making your energy go further and actively rejecting the "use less" narrative. ### Enhancing home comfort Beyond financial savings, insulation dramatically improves the comfort of your home. It helps maintain consistent indoor temperatures, eliminating cold spots and reducing draughts. This creates a more pleasant and stable living environment. Good insulation can also offer improved acoustic performance, reducing noise transmission from outside. Framing insulation as an investment in comfort and well-being, rather than a mere necessity, highlights its true value. ### Future-proofing your property Insulating your home is a strategic move that future-proofs your property against rising energy costs and evolving building standards. An energy-efficient home is more attractive to potential buyers, increasing its market value. Furthermore, by optimising your home's thermal performance, you're building resilience against future energy price fluctuations. This aligns with the idea that effective insulation allows homeowners to get more out of the energy they use, making every kilowatt-hour work harder for comfort and reducing energy waste. While direct insulation grants for owner-occupiers are less common, schemes like the Great British Insulation Scheme (GBIS) may offer support for eligible households, particularly those with lower incomes or less efficient homes. Insulation boards are a foundational step towards a home where energy is abundant and comfort is unwavering. By understanding the different types, considering key selection factors, and ensuring best practices in installation, you empower yourself to make informed decisions that lead to a more energy-efficient, comfortable, and future-ready property. Making your home more energy efficient with insulation is a smart move. When you're ready to take control of your energy usage, Fuse Energy offers clear pricing, real-time usage data through our app, and 24/7 human customer support. Switching to Fuse is quick and easy, helping you manage your bills effectively. Click [here](https://www.fuseenergy.com/app/boarding/premises) to switch to Fuse Energy today and discover a simpler way to power your home. You can also find out more about our mission to make energy abundant by clicking [here](https://www.fuseenergy.com/mission). --- Rates, availability, and regional off-peak windows change. Check the source page for current terms. **Disclaimer** For the avoidance of doubt, this article is provided for informational purposes only and is not intended to constitute legal or financial advice. The author and/or Fuse Energy shall not be responsible for any losses arising out of any reliance on the information contained herein.