Thermal Performance Report – James Fricker (2024)
Independent Thermal Engineering Verification
ThermaDoor’s R-values are not manufacturer claims — they are independently calculated by a registered thermal engineer to AS/NZS 4859.2:2018.
R1.43
Winter Assembly R-Value
R1.39
Summer Assembly R-Value
AS/NZS 4859.2:2018
Verified Standard
ThermaDoor is Australia’s original and only purpose-made garage door insulation with independently verified Total Assembly R-values — the only measure that reflects real-world thermal performance in a garage door. This page presents the full independent engineering report prepared by James M Fricker Pty Ltd, a Registered Professional Engineer, confirming the thermal performance of the 35mm ThermaDoor system to AS/NZS 4859.2:2018 — the Australian Standard referenced by NCC 2019 and NCC 2022.
For builders, energy assessors, and industry professionals, this ThermaDoor R-value report provides the verified, compliant performance data needed to specify an assembly R-value for a garage door with complete confidence.
Why Wall and Ceiling R-Values Are Misleading for Garage Doors
When insulation is sold for walls and ceilings, the R-value quoted often refers to either the material R-value or an assembly R-value calculated for those specific spaces. While these figures are accurate for their intended use, they are fundamentally misleading when applied to garage door insulation. Here is why.
A material R-value is a laboratory measurement of the insulation product itself, in isolation, without consideration of the application. It does not account for how the product will perform once installed in a real-world structure.
An assembly R-value (or Total R-value) for a wall or ceiling accounts for the entire structure, including the insulation, framing, and air gaps. These spaces often allow for very large air gaps and incorporate materials (like timber framing or brickwork) that provide some inherent thermal resistance. When insulation is added to a wall, it works with the existing structure, and the combined assembly R-value is higher than the insulation alone.
A standard garage door starts at R0.0. It provides no inherent thermal resistance whatsoever. The steel or aluminium skins and frame conduct heat directly, meaning the door assembly — as a whole — offers zero resistance to heat transfer before any insulation is applied. This is not a minor technicality. It means that any product claiming a wall or ceiling assembly R-value, or even a high material R-value, and applying that figure to a garage door application is overstating performance. The starting point for a garage door is not neutral — it is zero, and the steel frame actively undermines the insulation.
Furthermore, when insulation is simply adhered to the interior face of a garage door panel, the metal frame remains fully exposed and continues to conduct heat unimpeded. This is thermal bridging. As defined by the Australian Building Codes Board (ABCB), a thermal bridge is an unintended path of heat flow that bypasses insulation in favour of a more conductive material. The whole garage door acts as a thermal bridge, a factor not taken into account in material R-values. Because steel conducts heat roughly 1,500 times more efficiently than foam insulation, thermal bridging in a garage door will significantly reduce a material R-value once installed.
The only accurate measure of garage door insulation performance is a Total Assembly R-value calculated for the complete door system — including the door skins, air gaps, foil, insulation, and framing — in accordance with AS/NZS 4859.2:2018. ThermaDoor is the only garage door insulation in Australia that has been tested and verified to this standard.
The Australian Standard Behind Verified Garage Door Insulation R-Values
The R-value of garage door insulation in Australia is governed by a specific standard that most product brochures never mention: AS/NZS 4859.2:2018 — Thermal Insulation Materials for Buildings: Part 2: Design. Understanding this standard is essential for anyone specifying insulation for NCC compliance.
Prior to 2018, Australian insulation standards focused primarily on material R-values — the thermal resistance of a product measured in isolation under controlled laboratory conditions. This approach was adequate for simple applications but failed to capture the complexity of real building assemblies, where heat does not travel only through the insulation but also through framing, fixings, and other conductive elements.
AS/NZS 4859.2:2018 was introduced to address this gap. The standard establishes the methodology for calculating Total R-values and System R-values for complete building assemblies. Critically, it incorporates the calculation method from NZS 4214 (Methods of Determining the Total Thermal Resistance of Parts of Buildings), which accounts for the effect of thermal bridging on overall thermal performance.
The standard is referenced directly in both NCC 2019 and NCC 2022, making Total R-value calculations — with thermal bridging accounted for — the benchmark for energy efficiency compliance. The Australian Building Codes Board (ABCB) states clearly that Total R-values must account for thermal bridging in steel and metal-framed construction types.
The practical impact is significant. A product with a material R-value of R1.5 installed in a steel-framed assembly may deliver a Total Assembly R-value considerably lower than R1.5 once thermal bridging in the garage door is factored in. The gap between the claimed material R-value and the actual assembly R-value for a garage door can be substantial — and for garage doors, where the entire structure is metal, that gap is at its widest. ThermaDoor is the only garage door insulation in Australia with an independently verified assembly R-value calculated to this standard.
How Thermal Bridging Affects Garage Door Insulation Performance
Thermal bridging is defined by the Australian Building Codes Board (ABCB) as “an unintended path of heat flow between the outside and inside of the building envelope.” It occurs wherever a highly conductive material interrupts or bypasses the insulation layer.
In a garage door, thermal bridging is not an edge case — it is the dominant characteristic of the assembly. The entire door is constructed from steel or aluminium: the outer skin, the inner skin, the horizontal rails, the vertical stiles, and the hinges. Every one of these elements conducts heat at a rate many times greater than the insulation material between them.
The ABCB notes that thermal bridges “can significantly reduce the effectiveness of the insulation (thermal resistance) of the façade by essentially bypassing the insulation in favour of a more conductive material.” For a garage door, this effect is compounded by the fact that the door starts at R0.0 — unlike a wall, there is no existing thermal mass or structural resistance to offset the bridging.
This is why ThermaDoor was engineered as a complete system — not simply a foam insert. The 35mm M Class EPS panel is paired with a reflective foil facing and an unventilated reflective air gap, which together create a multi-layer thermal barrier that significantly reduces the impact of the metal frame. The result is a verified assembly R-value for a garage door that reflects genuine, real-world performance, mitigating the severe effects of thermal bridging in the garage door.
NCC 2025 Compliance: Condensation and Garage Door Insulation
The trajectory of Australian building standards is clear. NCC 2022 introduced mandatory thermal bridging requirements for metal-framed walls, roofs, ceilings, and floors in residential buildings, requiring that Total R-values be calculated in accordance with AS/NZS 4859.2:2018. NCC 2025 extends and tightens these requirements further, with a particular focus on condensation management — including mandatory ventilated wall cavities in Climate Zones 6, 7, and 8, and updated membrane permeability requirements across all climate zones.
Condensation occurs when warm, moist air contacts a cold surface and water vapour condenses into liquid. In a garage door assembly, the cold metal skin is precisely that surface. Without a moisture barrier within the panel assembly, condensation can form behind the insulation, leading to mould growth, structural degradation, and indoor air quality issues — the very problems NCC 2025 is designed to address across the building envelope.
ThermaDoor addresses this risk through the inclusion of construction-grade sisalation foil laminated to the face of the EPS panel. Sisalation is a Class 1–2 vapour barrier, providing strong resistance to moisture vapour movement through the assembly. Within a closed garage door panel — which is not subject to the same external wall membrane requirements as a house frame — this vapour barrier function reduces the risk of moisture-laden air reaching the cold metal door skin and condensing.
It is important to note that the sisalation foil is not the primary thermal element of the ThermaDoor system — that role belongs to the 35mm M Class EPS, which delivers the bulk of the verified garage door insulation R-value. The foil contributes to thermal performance through its low-emissivity surface (emissivity 0.03, as recorded in the Fricker report), which reduces radiant heat transfer across the reflective air gap. Together, the EPS and sisalation foil function as an integrated system: the EPS provides bulk thermal resistance, the foil provides radiant resistance and moisture protection, and the air gap amplifies both.
As energy efficiency expectations continue to rise — with NatHERS 7-star ratings now mandatory for new homes under NCC 2022 — the thermal performance of every element of the building envelope comes under greater scrutiny. The garage door, which can occupy up to one-third of a home’s front façade, is no longer a component that can be overlooked in energy assessments. Builders and energy assessors who specify ThermaDoor today are specifying a product already aligned with the direction of the NCC — one with verified, compliant assembly R-values, an integrated moisture barrier, and thermal bridging fully accounted for.
The James Fricker Engineering Report: Verified Assembly R-Values
The following independent ThermaDoor R-value report was prepared by James M Fricker, F.AIRAH F.IEAust CPEng NER APEC Engineer IntPE(Aus), a Registered Professional Engineer (Victoria PE0005355) and Chartered Professional Engineer of Engineers Australia. Mr Fricker is one of Australia’s most respected thermal performance engineers, with extensive experience in insulation assessment to Australian and international standards.
The report (Report i424b, dated 13 May 2025) determines the Overall Total Thermal Resistance (Total R-Value) of the 35mm M Class EPS ThermaDoor™ system for both winter and summer conditions, calculated in full accordance with AS/NZS 4859 Parts 1 and 2:2018.
© ThermaDoor Pty Ltd | thermadoor.com.au
This report is the intellectual property of ThermaDoor Pty Ltd. It is published here in full in accordance with the conditions of the report. Results may not be quoted without reference to the engineering assumptions contained within. This report may not be reproduced, altered, or misrepresented in any form. Unauthorised reproduction or doctoring of this report is strictly prohibited and may constitute a breach of copyright and professional standards.
Calculated by James Fricker, F.AIRAH F.IEAust CPEng NER APEC Engineer IntPE(Aus) — Registered Professional Engineer (Victoria PE0005355).