Thermal Performance Report – James Fricker (2024)
ThermaDoor Independent Thermal Engineering Verification
ThermaDoor’s R-values are not manufacturer claims — they are independently calculated by a registered thermal engineer to AS/NZS 4859.1 & 2:2018.
R1.43
Winter Assembly R-Value
R1.39
Summer Assembly R-Value
AS/NZS 4859.1/2:2018
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 4859.1 & 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 Most Garage Door Insulation R-Value Claims Are Misleading
Key Points
- Standard garage doors start at R0.0 — steel conducts heat, it does not resist it
- Most garage door insulation products either quote no R-value at all, a material R-value that ignores thermal bridging, or a wall/ceiling assembly R-value that does not apply to garage doors — all of which overstate real-world performance
- Some products quote a wall or ceiling assembly R-value as their garage door performance figure — a number calculated for a completely different structure with different framing, air gaps, and thermal mass. When applied to a steel door assembly, those figures overstate real-world performance, because the steel frame thermally bridges the insulation and reduces the contribution of the insert.
- AS/NZS 4859.2:2018 now requires Total Assembly R-values that account for thermal bridging through the steel frame
- ThermaDoor is the only garage door insulation in Australia with an independently verified Total Assembly R-value calculated 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.
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, creating 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 — with thermal bridging fully accounted for.
ThermaDoor is the only garage door insulation in Australia with an independently verified Total Assembly R-value calculated to AS/NZS 4859.2:2018 — with thermal bridging fully accounted for.
NCC Alignment, 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. Subsequent NCC editions extend and tighten these requirements further, with a particular focus on condensation management — including mandatory ventilated wall cavities in higher climate zones 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. ThermaDoor addresses this through the inclusion of construction-grade sisalation foil laminated to the face of the EPS panel — a Class 1–2 vapour barrier that reduces the risk of moisture-laden air reaching the cold metal door skin and condensing.
The sisalation foil also 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 35mm M Class EPS, the sisalation foil, and the unventilated air gap 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.
Home Energy Rating looks at the home as a whole, not one product in isolation. But where a garage is attached to the home, sits below or beside living areas, or affects heat transfer into adjoining rooms, the garage door can become part of the energy-performance conversation. As NatHERS minimum star ratings continue to rise, the thermal performance of every element of the building envelope — including the garage door, which can occupy up to one-third of a home’s front façade — comes under greater scrutiny. ThermaDoor gives builders, homeowners, and energy assessors verified garage-door assembly R-values and product documentation to review when assessing a suitable sectional or tilt garage door.
ThermaDoor does not guarantee a NatHERS or Home Energy Rating result. Rating outcomes depend on the whole home, including design, orientation, glazing, insulation, ventilation, air leakage, garage connection, and assessment method.
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.
View the full engineering report:
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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).