Specify with Confidence – EXPOL

EXPOL is New Zealand’s trusted name in polystyrene insulation, backed by over 45+ years of industry experience, BRANZ appraisals, and a commitment to ongoing R&D and sustainable manufacturing.

Our Technical Team supports you from concept to compliance, with proven methods that optimise slab design for cost-efficiency without compromising thermal performance. With nationwide distribution through merchant networks and a reputation for reliability, EXPOL is the smart choice for architects who demand real performance and real support.

Long-Term Advantages
of Slab Insulation

No Changes Required in Construction Methods: Simplifies implementation.
Maintains Performance Over Time: Slab insulation remains effective with no slumping.
Retrofitting Challenges: Slab insulation must be installed during construction; retrofitting is difficult and costly.
Enhanced Wall Insulation Performance: When paired with slab edge insulation.
Reduced Risk of Mould: Warmer slab edges minimise condensation.
Improved Thermal Performance: Decouples the building from ground temperatures.
Future-Proofs Homes: Aligns with New Zealand’s emission reduction targets.

Save on Build Costs – Insulate the Slab First

EXPOL’s thermal modelling indicates potential build cost reductions of up to $4,400 on a typical 180m² single-storey home, without compromising on performance or code compliance.

Cost-Saving Strategy Highlights:

Roof Insulation Reduction: Decrease from R6.6 to R3.3.
Slab Insulation Enhancement: Increase from R1.5 to R2.0 or higher.
Overall Savings: Potential savings between $1,600 to $4,400 for a 180m² single-storey home.

Achieve Compliance
and Reduce Costs

Estimated Cost Savings by Climate Zone

* Estimated cost savings are based upon a single story 180m2 home, with cost to build $3,271 + GST / m2. Cost savings are achieved by reducing roof insulation levels and increasing slab insulation levels, using the H1 / AS1 Calculation Method to comply with the New Zealand Building Code.