Slab Edge Insulation and H1 Compliance: What You Need to Know

With MBIE’s recent announcement to remove the Schedule Method for insulation compliance from the H1 Insulation Requirements by the end of 2025, slab edge insulation becomes even more valuable. Designers using the Calculation or Modelling Methods can optimise performance in key areas like slab edges to meet H1 requirements more efficiently.

What is Slab Edge Insulation?

Slab edge insulation is applied around the perimeter of a concrete foundation to reduce heat loss through the edges of the floor slab. While under-slab insulation targets heat escaping from below, the slab edge is where the majority of thermal loss occurs, especially in colder climates.

According to BRANZ, “thermal modelling has shown that approximately 80% of the heat lost from a concrete floor slab is at the edge and that the thermal resistance does not significantly improve by fully extending the insulation under the slab or by increasing the thickness of the insulation under the slab.” This makes slab edge insulation one of the most effective strategies for improving a home’s thermal performance.

Why Slab Edge Insulation Matters

• Improved Thermal Efficiency: Minimises edge-related heat loss, helping to maintain stable indoor temperatures.

• Lower Energy Use: Less heat escapes means less energy required for heating and cooling, resulting in cost savings.

• Better Moisture Control: Reduces the chance of condensation forming at floor edges, protecting the structure from mould and dampness.

Built Into SuperSlab+

At Allied Concrete, we offer slab edge insulation as part of our SuperSlab+ system, a high-performance foundation designed to meet H1 compliance, especially under the more flexible Calculation and Modelling pathways now recommended by MBIE. Using QuickSet or QuickEdge, this solution is not only cost-effective and simple to install, but also compatible with standard formwork systems, helping reduce both installation time and on-site waste.

Supporting Smarter Foundation Design

Whether you’re working on a residential build or planning a multi-unit development, Allied Concrete has the expertise and systems to support your foundation needs, including thermal advice and insulation options that align with H1 requirements.

To learn more about SuperSlab+, including our integrated insulation solutions, visit our SuperSlab+ product page or contact our team today.

Ready to Design for H1 Compliance?

DesignHub makes it easy. Created specifically for specifiers by Allied Concrete, DesignHub offers direct access to professional engineering and design services, helping you get concrete foundations and floors designed right, first time. 

Request a free design consult or SuperSlab+ spec through DesignHub.

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