Peter is a licensed builder with over 45 years of experience in the construction industry. In 2012, his expertise in energy efficient construction inspired the invention of ThermaDoor Premium garage door insulation - the original purpose made garage door insulation in Australia.
If you’re trying to keep your garage cool in summer in Australia, you’re not alone. Every year, thousands of homeowner’s battle garages that turn into ovens, making the rooms above or beside them unbearably hot and forcing air-conditioning to run nonstop just to cope. A standard uninsulated metal garage door has an R-value of R0.0, meaning zero protection against heat transfer, and is often the single biggest reason your garage reaches extreme temperatures on hot days.
The good news? There is a proven, cost-effective solution that stops heat at the source and makes your garage dramatically cooler, more comfortable and usable all summer long without air-conditioning hacks, fans, or expensive renovations.
Australian garages routinely reach 50–80°C inside on hot days, especially if the garage door faces west or north, is a dark colour, or is made from bare sheet metal.
The garage door is the single largest source of heat gain in the entire space.
A standard uninsulated garage door has an R-value of R0.0 — meaning zero thermal resistance. It behaves like a giant oven door, letting heat pour directly into the garage and into the rooms beside and above it.
Common signs your garage is overheating:
Feels like an oven in the afternoon
Bedrooms above or beside are unbearably hot
Air-con running constantly without results
Tools, food storage, or gym equipment heating up
Paint and plastics starting to warp
Pets refusing to use the garage
Sound familiar? You’re not alone.
Insulate the garage door properly to stop heat at the source
One of the most powerful cooling improvements comes from insulating the garage door itself.
Proper insulation stops heat from radiating into the garage and helps regulate temperatures in the surrounding rooms.
Real outcomes experienced after insulating the garage door
✔ Homeowners commonly report ambient temperature improvements of 10–15°C after insulating the garage door
✔ Bedrooms next to the garage feel noticeably cooler
✔ Air-con workload is reduced
✔ Garage becomes usable again (gym, workshop, storage, playroom)
When insulation is designed and built specifically for moving panel lift or tilt garage doors and installed correctly, the results are dramatically better and far safer than repurposed wall or foil products.
Not all insulation products are designed for garage doors. Many products on the market claim impressive numbers using surface temperature readings or roof/wall insulation repurposed for garage doors, but without verified assembly R-values or correct installation, the real-world performance is nowhere near as effective.
Foil glued directly to metal or PIR wall panels introduce performance and safety issues — including loss of the air gap, added weight, moisture absorption and potential motor damage.
The right garage door insulation must be:
| Requirement | Why it matters |
|---|---|
| Purpose-built for garage doors | Handles movement & vibration safely |
| Installed with air cavity | Delivers real thermal performance |
| Mechanically fixed – not glued | Doesn’t fall off or damage the door |
| Lightweight & motor safe | Won’t strain the motor or springs |
| Verified R-values to Australian standards | Real performance, not guessing |
| Suitable for Australian climate | Heat, humidity & storm-safe |
Purpose-built garage door insulation — not wall, floor or ceiling products repurposed
| Feature | Benefit |
|---|---|
| R1.47 (winter) / R1.40 (summer) | Real dual-season thermal performance backed by thermal engineering reports |
| Mechanically fixed — no glue | Protects air gap & structural integrity |
| Laminated vinyl front | True premium finish that increases durability & lasts years |
| Lightweight & motor-safe | Springs adjusted & door balanced to accommodate for even the most minimal additional weight |
| DIY or Fully Installed | Options for every budget |
| Australian-made | Built for our climate, heat and humidity |
Work out without the sweat-box heat. Stay cool and comfortable even on 40°C days.
Beat the summer heat and keep your workspace cool, quiet and focused — no more sticky Zoom calls.
Enjoy real downtime in a space that stays cool all summer — the perfect escape from the heat.
Protect your projects from extreme heat and create in comfort all summer long.
Keep the kids cool and safe from heat stress — a comfortable room they’ll actually want to play in.
Reduce heat stress for pets with a cooler, safer space when temperatures soar.
ThermaDoor is available Australia-wide as:
DIY Kits
Supply & install
If you want to keep your garage cool in summer in Australia without relying on air-conditioning, ThermaDoor is the proven solution.
Get a fast, free quote – DIY or professional installation Australia wide
Yes. When installed correctly with an air cavity and lightweight panels, insulation dramatically reduces heat transfer and improves ambient temperature.
Typically 10–15°C cooler ambient depending on climate, door colour, orientation & construction.
Yes — professionally installed insulation includes spring adjustment to maintain safe balance and protect your motor.
Yes — we deliver DIY kits nationwide and have installers in major regions.
Australian Building Codes Board (ABCB) — Housing Energy Efficiency Handbook (PDF)
Housing Energy Efficiency Handbook – ABCB Australian Building Codes Board
Covers insulation requirements, including garages and attached spaces (see Clause 13.2.7).
Your Home (Australian Government) — Insulation (materials & standards)
Insulation – Your Home YourHome
Explains how insulation materials must meet AS/NZS 4859 for Australia/NZ, and the difference in R-value units.
Queensland Building and Construction Commission (QBCC) — Standards & Tolerances Guide (Queensland)
Standards and Tolerances Guide – QBCC qbcc.qld.gov.au
Details how building standards in Queensland reference the National Construction Code (NCC) and relevant Australian Standards for building work.
ABCB — Part 13.4 Building Sealing – NCC 2022 (Housing Provisions)
Part 13.4 Building Sealing – NCC 2022 National Construction Code
Explains requirements for sealing external doors and openings, which is relevant when insulating a garage door to prevent air leakage.
Business Queensland — 7-Star Energy Standard for Houses & Townhouses
7-Star Energy Standard – Business Queensland Business Queensland
Explains how new houses (and their attached garages) must comply with energy-efficiency standards, which links to garage door insulation relevance.
Call, text, or send an enquiry below to see if we have an installer in your area.
