How Can EPS Maximise Energy Efficiency? A Comprehensive Guide

EPS Insulation UK: Top 5 Energy Efficiency Benefits

Making homes more energy efficient is good for the planet. It also helps households cut energy use and reduce bills. One of the most effective ways to improve a home’s performance is good insulation. EPS insulation helps reduce heat loss and helps keep indoor spaces comfortable.

In the UK, housebuilders, specifiers and homeowners often choose EPS (expanded polystyrene) insulation because it is proven, cost-effective and easy to work with. It helps deliver strong U-values and supports compliance with Part L of the Building Regulations. EPS is also durable, meaning its performance stays stable over time.

In this guide, we explain five ways EPS insulation improves energy efficiency, across walls, roofs, floors, foundations and modern building systems like SIPs. We also explain how Engineered Foam Products and Springvale supports the construction sector with certified EPS solutions.

Top 5 ways EPS insulation improves energy efficiency in homes

1) Reduces heat loss through walls

Walls are one of the biggest areas of heat loss in many homes. EPS helps by forming a reliable insulating layer.

Common wall solutions include:

• EPS boards
• External Wall Insulation (EWI) systems
• Cavity wall solutions, including blown bead systems such as Springvale Ecobead® Platinum

Used correctly, these systems create a more continuous thermal envelope. That means less heat escapes through external walls.

2) Improves roof insulation performance

Heat rises, so roofs are another major route for heat loss. EPS roof insulation can be used on both flat and pitched roofs to help reduce heat escaping from the top of a building.

With professional installation, EPS can help improve overall fabric performance and energy ratings.

3) Creates warmer, more efficient floors

Cold floors can make a home feel uncomfortable and can increase heating demand. EPS floor insulation helps reduce cold spots at ground level.

EPS can be used in:

• solid floor build-ups
• suspended floor systems
• beam and block floors, using EPS infill between beams plus an EPS overlay above

This improves thermal performance and helps achieve required U-values for the floor element.

4) Protects foundations and reduces thermal bridging

Thermal bridging happens where insulation is interrupted, often at junctions (for example, wall-to-floor connections). These weak points can increase heat loss.

EPS foundation systems can help reduce this risk, especially when supported by:

• good detailing at key junctions
• linear thermal transmittance (ψ) values to support accurate energy modelling

These ψ-values can be used within SAP calculations, supporting stronger outcomes for EPC ratings.

5) Supports high-performance building systems

EPS is widely used in modern methods of construction. It can be part of systems that combine structure with insulation to deliver high performance.

Examples include:

• Structural Insulated Panels (SIPs)
• EWI boards
• prefabricated wall panels

These systems help designers meet tougher targets, including the direction of travel set by the Future Homes Standard and the UK’s long-term energy efficiency goals.

EPS insulation as an energy-efficient solution

• EPS floor insulation
• EPS boards for walls
• EPS Blown Bead (used in cavity wall insulation)
• EPS foundations systems (ideal for passive house builds)
• EPS Sheets (suited to EWI applications)
• EPS wall panels (suited to SIPs Panels and building prefabrication)
• EPS roof insulation (which can be cut to match the fall of the roof)

At Engineered Foam Products we supply various grades from EPS70 up to EPS500 in white and EPS70 to EPS100 in grey, with a thermal performance from 0.038 to 0.030 W/(m·K). Typically, lower grades of EPS are used for insulation and higher grades are used for civil engineering applications like GeoFill for road and rail projects, embankments and landscaping.

Properties of EPS insulation that contribute to energy efficiency

EPS insulation is produced from a mixture of about 90-95% polystyrene and 5-10% gaseous blowing agent, most commonly pentane. The raw material is expanded using steam and is injected into an aluminium tool under high pressure. 

Whether white or grey, this EPS insulation starts life the size of a grain of salt. Once the raw material has gone through the pre-expansion process, the grain swells with air, expanding up to 40 times its original size. The properties of this polystyrene insulation include: 

• High thermal resistance 
• Thermal performance that will not deteriorate over time
• Moisture resistance 
• Lightweight and easy to install 
• Durability that increases the lifespan of the product
• High compressive strength
• Reaction to Fire performance Euroclass E
• Off cuts and scrap 100% recyclable

EPS insulation offers a balanced combination of performance, cost-effectiveness and environmental benefits over other insulation materials available. 

EPS in wall insulation UK

External Wall Insulation (EWI) systems involve attaching EPS insulation boards to the exterior walls of a building, followed by a protective render or cladding. This method provides a thermal envelope around the building, improving energy efficiency and reducing heat loss.

In cases where external wall insulation isn’t possible, such as in listed buildings. EWI suppliers can provide EPS wall panels that can be fitted be to the interior walls. 

Cavity Wall Insulation (Blown Bead)

As part of the combined EFP Springvale offer, Ecobead® Platinum is a high-performance EPS cavity wall insulation system for both new build and retrofit projects. Injected as graphite-enhanced beads with a binding agent, it forms a continuous, full-fill layer within the cavity, reducing gaps, cold spots and heat loss through the external walls.

With a declared thermal conductivity of 0.033 W/(m·K), Ecobead Platinum helps designers achieve excellent wall U-values and support compliance with Part L of the Building Regulations. Springvale also provides linear thermal transmittance (ψ) values for key junctions, calculated in line with conventions such as BR 497; these ψ-values are then used by energy assessors within their SAP calculations to model overall heat loss and demonstrate that new homes meet the required energy performance standards. The system is installed by approved contractors, is quick to apply, generates minimal on-site waste and is designed to perform for the life of the building.

Ecobead Platinum is moisture-resistant, inert and 100% recyclable at end of life, making it a robust, low-maintenance solution for specifiers looking to balance thermal efficiency, buildability and sustainability in modern cavity wall construction.

EPS Roof Insulation

EPS insulation can be installed on both flat and pitched roofs. In flat roofs, EPS insulation boards are placed above the roof deck and below the waterproof membrane. In pitched roofs, the insulation can be fitted between and over the rafters, or above the ceiling joists and systems like Springvale’s Warmsqueez / Warmsark are specifically designed for this, with Warmsqueez installed between rafters and Warmsark installed under or over rafters, available in white or Platinum EPS grades to help achieve required U-values.

Each technique can deliver enhanced thermal efficiency when specified correctly and installed professionally. Building surveyors use SAP calculations to generate an EPC (Energy Performance Certificate), which provides a rating for the building’s energy performance and insulation plays a critical role in improving that overall score.

EPS Floor Systems

EPS floor insulation can be installed over a concrete slab, or below a concrete slab to provide insulation from the ground up. It can also be installed above a concrete suspended floor. EPS floor insulation provides great energy efficiency, contributes to a more comfortable home environment, and offers excellent moisture resistance.

In beam and block flooring systems, grey EPS infill panels are positioned between the beams with a grey EPS overlay sheet on top to enhance thermal efficiency and improve the overall energy performance of the building. Different depths of the overlay sheet can be used to achieve the necessary ‘U’ value. The ‘U’ value measures heat loss through a building’s fabric and is regulated by building codes.

What is grey insulation?

Grey or Graphite is an advanced EPS insulation material that incorporates graphite particles to enhance its thermal properties over the standard white EPS. It reflects radiant heat, which leads to improved energy efficiency and lower energy costs. Grey EPS can be installed in thinner layers, which makes it ideal for space-limited applications.

EPS foundation insulation

When EPS is used as part of a house foundation system to encapsulate the concrete slab you can achieve a passive house standard that uses 90% less energy for heating and cooling compared to traditional homes, which can have a significant impact reducing running costs.

EPS insulation can be installed on either the interior or exterior of the foundation walls or under the concrete slab of the foundation to help protect against structural damage and provide a thermal barrier between the cold foundation walls and the indoor environment. 

SIPs and energy efficiency

Structural insulated panels (SIPs) consist of EPS insulation sandwiched and glued between two sheets of Oriented Strand Board (OSB). SIPs can be used in walls, floors and roofs and easily slot together to offer exceptional energy efficiency properties. They combine insulation with structural strength to provide lightweight yet high-performance solutions for sustainable building.

SIPs with EPS insulation boast a high thermal resistance that can help reduce thermal bridging. This results in more consistent temperatures in the building and can help further reduce energy consumption and costs. 

Future of energy efficiency: Innovations in EPS insulation

EPS insulation is playing a crucial role in the UK’s Future Homes Standard by supporting the government’s goal of achieving net-zero carbon emissions for new homes by 2050. Its excellent thermal efficiency helps meet stricter energy performance requirements, while its A+ BRE rating ensures sustainability. Additionally, EPS contributes to lowering heat loss and improving airtightness in building envelopes, which are key factors in reducing energy consumption. The materials recyclability and compliance with building standards make it ideal for future low-carbon construction solutions.

More and more are council planners looking to ensure that new builds and extensions contribute positively to the environment around them. Builders and architects now more than ever need to ensure they have considered mitigations as part of any planning application. 

EPS insulation can assist with the planning application by significantly enhancing the thermal efficiency of the new dwelling’s envelope. It can help achieve a high SAP rating by minimising heat loss and maintaining consistent indoor temperatures, reducing energy demand. EPS also support air-tightness, which complements building design for further lowering energy input by reducing drafts and uncontrolled airflow. Combined with an Air Source Heat Pump (ASHP), EPS insulation further enhances energy efficiency, making the heating systems more effective by minimising energy losses.

Why Choose EPS?

EPS offers a cost effective alternative to PIR (Polyisocyanurate) and Phenolic insulation and performance doesn’t deteriorate over time.

EPS is a versatile and cost-effective option for maximising energy efficiency within our buildings. Its high thermal resistance, moisture resistance and durability make it an ideal choice for various applications, including wall, roof, floor and foundation insulation.

By choosing Expanded Polystyrene insulation, homeowners and construction professionals can get a step closer to meeting the requirements set out in Part L of the Building Regulations for England and Wales (Conservation of Fuel and Power) by providing high thermal performance, reducing heat loss and improving energy efficiency in buildings, which lowers energy consumption.

In relation to Part O (Overheating), our EPS materials help maintain thermal balance by minimising excessive heat transfer, reducing the need for excessive heating in well-insulated homes. EPS thus supports sustainable building practices and regulatory compliance and significantly reduces energy consumption of the buildings we work and live in.

Engineered Foam Products (EFP) and Springvale are now one team. Two industry leaders united to drive innovation and sustainability in the delivery of EPS solutions for the construction sector. With a deep expertise in advanced foam manufacturing, we combine strengths to enhance quality, reliability and capabilities for our customers.

EFP Springvale unites the UK’s largest EPS/EPP capability with certified systems, in-house design/prototyping and a wider national coverage. We support the construction industry to deliver compliant thermal performance, lighter and faster installs, and geofoam solutions for civils.

Please get in touch should you have a requirement for our materials and services.

Tags: Construction, Energy Performance, EPS Insulation