3 Car Garage: Triple Garage Sizes, Designs, and Colorbond Options in Australia (2025 Guide)

30 Oct Caravan Storage Solutions

What size is a triple garage in Australia?

A 3 car garage (also called a three bay garage or triple garage shed) typically spans 8.4–10.8 metres wide with 6–8 metres depth. Height depends on vehicle clearance and door type.

  • Common triple garage width: 9.0 m, 9.5 m, or 10.5 m
  • Typical depth: 6.0 m to 7.5 m for cars; 8.0 m+ if adding a workshop
  • Roller door openings: 2.4–3.0 m wide each, 2.1–2.7 m high
  • Eave height: 2.7–3.6 m (allow more for 4WDs, roof racks, or a hoist)

For caravans or boats, lift the eave height to 3.0–3.6 m and specify 3.0 m door height. If you need extra shade or boat overhang, consider a 3 bay shed with awning along one side.

What are the best shed materials for Perth’s climate?

Perth’s hot summers, coastal air, and strong sea breezes favour high-spec steel and coatings. Most premium steel sheds Perth builds use BlueScope COLORBOND or ZINCALUME cladding with hi-tensile galvanised frames.

Colorbond vs Zincalume — Which is better for WA conditions?

Feature COLORBOND (incl. Ultra/Matte) ZINCALUME
Corrosion resistance Excellent; choose COLORBOND Ultra near marine environments Very good; may weather faster near coast
Heat performance Thermatech solar reflectance reduces heat gain Highly reflective when new; dulls over time
Colour range Wide architectural colours to match homes Metallic silver-grey only
Cost Higher material cost; premium appearance More affordable
Best use Residential triple garage, coastal, design-led builds Budget rural sheds, internal linings, non-coastal

For coastal WA or exposed regional sites, specify COLORBOND Ultra cladding, galvanised or hot-dip galvanised columns, and stainless fixings. Add an insulation blanket or insulated roof panels to reduce radiated heat.

Related research and guidance:
Bureau of Meteorology climate data,
CSIRO building science,
Australian Steel Institute.

Which roof style suits a three bay shed?

  • Gable roof (10–25° pitch): Classic look, great drainage, good door clearance at centre. Best for taller vehicles and heavier rainfall.
  • Skillion roof (single pitch): Contemporary, simple gutters, ideal for solar PV orientation and lean-to awnings.

In high-wind regions, steeper roof pitches and stronger portal frames improve performance. A 3 bay shed with awning on the lee side adds shaded parking or a covered work zone.

How do wind ratings affect a triple garage?

Australian sheds must be site-specifically engineered to AS/NZS 1170.2 (wind actions). Wind Regions A–D and Terrain Categories change the required member sizes, hold-downs, and door bracing. Cyclone-prone areas (Region C/D) require upgraded frames and wind-locked doors.

  • Non-cyclonic (Region A/B): metro Perth, Adelaide, Sydney, Melbourne
  • Cyclonic (Region C/D): coastal QLD, WA north coast — choose wind-rated sheds for cyclonic areas

Added 2024 WA wind-rating compliance notes — For Perth and regional WA, ensure the engineering certificate references NCC 2022, AS/NZS 1170.2:2021, AS/NZS 4600 (cold-formed steel), AS/NZS 4100 (steel structures), and manufacturer span tables. This is essential for council-approved sheds WA.

How to get council approval for a 3 car garage

How to Get Council Approval for Your Custom Shed in WA

  1. Check local planning rules: setbacks, maximum height, streetscape and bushfire BAL if applicable.
  2. Order site-specific engineering: wind region, terrain, topography, and footing design.
  3. Prepare documents: site plan, elevations, slab plan, door schedules, colour schedule.
  4. Lodge a Building Permit application with a Certificate of Design Compliance (private certifier or council).
  5. Book mandatory inspections: footings, slab, and final.

For other states, processes are similar. Refer to your local council and the NCC 2022. Helpful resources:
Housing Industry Association,
Master Builders Australia.

Popular 3 bay shed designs and use-cases

  • Triple garage with workshop: 9.0 × 7.5 m gable, 3 roller doors + rear PA door, 900 mm bench space at rear.
  • Three bay shed with awning: 9.5 × 7.0 m skillion, 3.0 m × full-length awning for shaded work or boat parking.
  • Garage + storage: 10.5 × 6.0 m with an internal dividing wall for tools, bikes, and farm machinery storage.
  • Garage with carport: Enclose two bays; add a front custom carports Melbourne-style cantilever for the third vehicle.

Real build examples

Case Study 1 — Custom Colorbond Garage in Perth

A 9.5 × 7.5 m gable triple garage, Woodland Grey COLORBOND, 2.7 m eave height, anticon roof blanket, epoxy garage floor, and vermin flashing. Engineered for Region A, TC2, concrete slab on ground with integrated edge thickening for portal base plates. Perfect for a workshop-ready 3 car shed.

Case Study 2 — Cyclone-rated sheds QLD

In coastal QLD (Region C), a 9.0 × 7.0 m triple garage with wind-locked roller doors, upgraded purlins, additional cross-bracing, and hold-downs. External fasteners upgraded to Class 4, COLORBOND Ultra cladding. This is a model of cyclone-rated sheds QLD compliance.

Case Study 3 — Rural sheds NSW

10.5 × 8.0 m three bay shed with awning for tractor and ute, ZINCALUME walls, COLORBOND roof, 15° pitch for rain and leaf shedding, sarking and whirlybirds for condensation management. A practical rural sheds NSW solution.

5-Step Buying Guide for Custom Sheds in Australia

  1. Define the brief: vehicles, workshop space, caravan clearance, and future storage needs.
  2. Pick materials: COLORBOND for coastal/architectural, ZINCALUME for budget. Compare Colorbond vs Zincalume for your location.
  3. Choose the structure: portal frame spacing, eave height, door sizes, and a 3.0 m awning if needed.
  4. Engineer for site: wind region, terrain, soil class; specify site-specific engineering and ShedSafe accredited systems.
  5. Plan approvals and build: engage a slab contractor, organise delivery (DIY shed kits or install), and book inspections.

Doors, windows, and smart add-ons

  • Roller doors vs panel-lift: Roller doors suit high wind locks; panel-lift offers premium looks and sealing.
  • Personal access doors and windows: Cross-ventilation for fumes and heat; add security mesh where needed.
  • Electrical and lighting: Plan circuits, LED high-bays, 15 A outlets for welders, and EV chargers.
  • Insulation and condensation control: Anticon blanket or insulated panels, sarking, and ridge ventilation.
  • Lean-to awnings: Create shaded bays; perfect for a 3 bay shed with awning for outdoor work.
  • Storage systems: Mezzanine floors (check load limits), racking, and bicycle mounts.

Compliance checklist for a triple garage

  • NCC 2022 and local planning rules
  • AS/NZS 1170.2 wind actions, AS/NZS 4100 and AS/NZS 4600 steel design
  • AS 3600 concrete for slab/footings; engineer’s slab design
  • BAL assessment in bushfire-prone areas
  • Coastal corrosion strategy: COLORBOND Ultra, galvanised or stainless fixings

Energy and comfort tips:
Energy.gov.au guidance on insulation and ventilation can improve comfort in steel buildings.

Frequently asked questions about 3 car garages

What is the minimum triple garage width?

8.4 m is a tight fit for three small cars. Most homeowners choose 9.0–10.5 m for easier access and storage.

Do I need a permit?

Yes, most councils require a building permit and site-specific engineering. We supply permit-ready plans for council-approved sheds WA and across Australia.

Can I DIY a triple garage?

Yes, many choose DIY shed kits. For complex builds, sloping sites, or cyclonic areas, use licensed installers.

What roof height for 4WDs and racks?

Set eave height at 2.7–3.0 m with a 2.4–2.7 m door opening. Measure your tallest setup including racks and aerials.

Colorbond or Zincalume?

COLORBOND for coastal and design-led homes; ZINCALUME for budget rural applications. See our comparison above.

Technical terms you’ll hear (quick definitions)

  • Portal frame: The primary steel frames that carry roof and wall loads.
  • Terrain Category (TC): Surrounding roughness affecting wind speed at your site.
  • Importance Level (IL): Building risk category that adjusts design loads.
  • Vermin flashing: Perimeter flashing to seal cladding-to-slab gaps.
  • ShedSafe: Industry accreditation for engineered steel sheds.

Why homeowners choose our triple garages

  • Australian-made steel with high-tensile frames and galvanised purlins
  • COLORBOND or ZINCALUME cladding with manufacturer warranties
  • Site-specific engineering for wind regions A–D, snow loads where applicable
  • Roller doors with wind locks and heavy-duty tracks
  • Custom options: mezzanines, awnings, windows, and workshop fit-outs

Whether you’re after custom Colorbond garages Perth, affordable carports for Australian homes, or farm machinery storage, we design and deliver to suit your site.

Standards, reports, and useful resources

  • Australian Standards: AS/NZS 1170.2 (Wind actions), AS/NZS 4100, AS/NZS 4600, AS 3600
  • “2024 Australian Steel Market Outlook” — market conditions and local supply
  • “2024 HIA Outdoor Structures and Home Improvement Report” — demand trends for sheds
  • Industry info:
    HIA resources and
    Master Builders insights

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