Insulated Foundation System

Prefabricated insulated foundation system that wraps the entire foundation in EPS, reducing the wall to floor thermal bridge and enabling ground-floor U values from 0.09 W/m²K - 0.11 W/m²K.
Climate Change Mitigation Solutions Embodied carbon

Problem Addressed

Building foundations, particularly the wall-to-floor junction, are a key source of energy loss due to thermal bridging, where conductive materials such as concrete or steel allow heat to escape through the building envelope. These bridges can account for up to 30% of total heat loss, undermining thermal performance and increasing energy demand. They can also lead to condensation, mould growth, structural issues, and occupant discomfort.

Substructure construction is also one of the most complex and resource-intensive stages of the build process, requiring multiple trades, significant manual handling, and careful coordination. Ongoing skilled labour shortages in groundworks can contribute to delays, increased costs, and reduced productivity, while the physical nature of the work introduces additional health and safety risks.

From an environmental perspective, foundations are typically material-intensive, with concrete volumes contributing significantly to embodied carbon. Poor thermal detailing at this stage can also increase operational energy demand, making foundation design a critical challenge for both construction efficiency and whole-life carbon performance.

Solution Overview

KORE’s Insulated Foundation System wraps the entire foundation in a continuous layer of EPS, effectively reducing the wall‑to‑floor thermal bridge and enabling ground-floor U‑values as low as 0.09 W/m²K. It’s fully engineered and prefabricated, reducing groundworks and substructure times by approximately 20% and traditional concrete use by up to 40%, and it lowers embodied carbon by up to 30% compared to conventional strip foundations. The system has also achieved NSAI and BBA certification.

Components of the system may also be manufactured with KORE Low Carbon EPS. This lowers the embodied carbon of the EPS insulation by up to 90% in the manufacturing of the raw material, through replacing a portion of fossil-based feedstock with renewable inputs derived from plant or waste sources. This does not compromise performance, the insulation functions the same, but there is a cost premium of the feedstock to make the low carbon EPS.

There are various on-site benefits, including reducing the labour requirements for the sub-structure, which typically involves multiple trades and significant manual handling, as it can be installed like a jigsaw reducing the time onsite and increasing repeatability and efficiency. The system is also weather resistant so can be installed in wet and damp conditions reducing delays due to bad weather. As well as this it reduces on-site health and safety concerns due to it being lightweight and manufactured using no harmful chemicals meaning it is non-toxic and can be handled on-site without specialist equipment.

From a waste and circularity standpoint, the system can also reduce waste to landfill by up to two-thirds, when compared to traditional strip foundations. Both the conventional and low carbon products can be recycled at the end of its useful life, again promoting product circularity and reducing waste. Approximately 50% of the EPS insulation can be recycled at end of life. This would be made up of the lower layers of insulation that are not in direct contact with concrete. To maximise reuse potential it is advised to use a separation layer between the concrete and the foundation system this will increase the recyclable EPS material to approximately 85%. Alternatively, the system can be mechanically broken apart, and once it is ensured that the EPS is clean and free of concrete it can be recycled. The EPS also contained recycled content, which is typically 10% for the structural products and 18% for the lower density products.

KORE EPS comes with a full third-party verified Environmental Product Declaration by the Irish Green Building Council and EPD Ireland. KORE was the first EPS manufacturer in Ireland to receive this certification, which was updated again in 2024. Components of the system may also be manufactured with KORE Low Carbon EPS (mentioned above), further reducing the embodied carbon of the product.

Company name

KORE Insulation

UK availability

Yes

Solution launch date

2010

Links

Read more

Case Study

At Silken Park in Citywest, Dublin, KORE’s Insulated Foundation System played a pivotal role in delivering one of Ireland’s largest certified Passive House developments. The project, led by Durkan Residential and BBA Architecture, used KORE’s high-performance EPS system to wrap the building’s foundation in continuous insulation.

This approach eliminated thermal bridging at the wall-to-floor junction, significantly improving airtightness and reducing heat loss at the most vulnerable part of the building envelope.

The system resulted in exceptionally low u-values of 0.10 W/m²K. According to Passive House Plus Magazine, Phase 3 of Silken Park (3 bedroom, semi-detached) achieved a BER rating of A2 and a Y-Factor of 0.02, offering a virtually thermal bridge free building envelope. In addition, depending on the layout and the construction of each home, the air changes per hour varied from 0.20 to 0.29 ACH @ 50Pa.

In the UK, the Duneridge Co‑Housing Development at Findhorn Eco‑Village in Scotland is a community‑led residential project that demonstrates how a strong fabric‑first approach can support low‑energy, low‑carbon housing. The scheme prioritises energy efficiency, thermal comfort and long‑term sustainability through careful detailing of the building envelope, with particular emphasis on minimising heat loss at foundation level.

KORE’s Low Carbon Insulated Foundation System was specified for the project, achieving a floor U‑value of 0.10 W/m²K, helping to significantly reduce heat loss while also addressing embodied carbon at an early stage of construction. This performance‑led approach aligns with the wider environmental ethos of Findhorn Eco‑Village and provides a clear UK example of how high‑performance foundation systems can contribute to low‑energy residential developments.

The full case study can be viewed on the KORE Insulation website.

Links to additional case studies:

Silverbrook Housing Development

Lyreen Meadows Housing Development

Duneridge Co-Housing Development at Findhord Eco-Village

Facts and Figures

0.09 to 0.11 W/m2K

ground U-Values

Up to 30%

less embodied carbon compared to traditional strip foundations

~40%

reduction in concrete compared to traditional foundations

Related

A Better Built Environment with the UK Green Building Council

UKGBC brings together hundreds of organisations across the built environment to accelerate practical, ambitious policy and industry action for a decarbonised, nature-positive, climate-resilience UK. We work with industry, local authorities and government to shape evidence-based policy that delivers warmer homes, lower bills, good jobs, healthier places and stronger communities.
Policy Document