Double Garage: Standard Sizes, Dimensions, Prices and Buying Guide (Australia, 2025)

30 Oct Caravan Storage Solutions

What is the standard double garage size in Australia?

If you’re parking two cars side-by-side, the most common double garage dimensions in Australia are:

  • Standard: 6.0 m (L) x 6.0 m (W) x 2.4–3.0 m (H)
  • Popular upgrade: 6.0–7.0 m (L) x 6.5 m (W) x 3.0 m (H) for 4WDs and roof racks
  • Door opening: One double roller 4.8–5.2 m wide, or two singles 2.4–2.7 m each

For utes and 4WDs with lifts, consider a 2.7–3.0 m wall height. If you’re adding a workshop bench or storage, go to 6 x 7 m or 6 x 9 m to keep clear car doors and circulation.

Definition — Double garage: A two-bay (two car) garage typically classed as NCC Class 10a, often built in Colorbond steel with roller doors and concrete slab.

How wide is a double garage?

Standard double garage width in Australia: 6.0 m. If you have large SUVs or want shelving, go wider:

  • Comfort width: 6.5 m
  • Premium width: 7.0 m (great for a small workshop or bikes)

Minimum clear door width to feel roomy is 5.0–5.2 m for a single double door. Two singles give flexibility and better thermal performance when opening one bay at a time.

How big is a double garage with a workshop?

Popular combos for a double garage and workshop:

  • 6 x 9 m: 6 x 6 m for cars + 3 m workshop bay
  • 7 x 8 m: Extra depth for benches and mower storage
  • 6 x 10.5 m: Allows a rear roller door to backyard or farm machinery storage

Add a 3.0 m awning to create covered work space without fully enclosing more floor area.

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

In WA’s hot, coastal environment, durable cladding and correct coatings matter.

Colorbond vs Zincalume — Which is better for WA?

Feature Colorbond Steel Zincalume
Coating Painted alloy/zinc coating with baked-on colour Aluminium-zinc alloy (no colour)
Corrosion resistance Excellent; choose Ultra/Metallurgical coatings near coasts Very good; needs more maintenance near surf coast
Colour options Wide range, heat-reflective light tones Silver only
Price Higher Lower
Warranty Up to 20–36 years (conditions apply) Up to 20–36 years (conditions apply)
Best for Street-facing garages, premium builds, coastal suburbs Budget builds, rural sheds inland

Always confirm BlueScope warranty zones and washing maintenance if you’re within ~1 km of breaking surf.

Roof style and heat

  • Gable roofs vent heat better and suit whirlybirds or ridge vents.
  • Monopitch (skillion) looks modern and is easier near boundary walls.
  • Light Colorbond colours reduce heat load in Perth and inland WA.
Pro tip: Insulated roof panels or bulk insulation + sarking can reduce internal temperatures by as much as 5–10°C in summer depending on ventilation and colour. See guidance at Energy.gov.au.

Added 2024 WA wind-rating compliance notes: Perth metro typically uses non-cyclonic design (AS/NZS 1170.2 Region B; terrain category varies by site). Coastal or hill sites may require higher pressure coefficients and extra fixings. Ask for site-specific wind speed and council-approved sheds WA documentation.

Double garage dimensions, doors and heights

Common double garage measurements

  • Width: 6.0–7.0 m
  • Length: 6.0–9.0 m
  • Wall height: 2.4–3.6 m (3.0 m suits roof racks and small boats)
  • Roller door height: 2.1–2.7 m (go 2.7 m for lifted 4WDs)
  • Roller door width: 4.8–5.2 m (double) or 2.4–2.7 m (singles)

Slab and structure

  • Slab: Typically 100 mm thick, 25 MPa concrete with mesh (engineer to soil class)
  • Footings: Thickened edge beams or piers to engineer’s detail
  • Framing: Galvanised RHS/C-Section steel portal frames
  • Drainage: Full perimeter fall, high-capacity gutters and downpipes

Definition — Wind region (AS/NZS 1170.2): Australia is divided into Regions A–D. QLD coast and NT top end are cyclonic (C/D), much of inland is A, Perth and parts of WA are B (non-cyclonic). Design uplift pressures and fixings depend on region and terrain.

How much does a double garage cost in Australia?

Indicative 2025 pricing for a Colorbond double garage (6 x 6 m, non-habitable Class 10a), noting steel and freight markets remain volatile:

  • DIY double garage kit: $7,500–$13,500+ (non-cyclonic, no slab)
  • Installed shell (ex slab): $12,000–$22,000
  • Turnkey with slab, doors, gutters: $18,000–$35,000+

Allow extra for cyclonic design (cyclone-rated sheds QLD can add 20–40%+), coastal corrosion upgrades, custom windows, insulation, electrical, and council fees. For a double garage and workshop (e.g., 6 x 9 m), budgets from $24,000–$45,000+ turnkey are common.

References: HIA outdoor structures insights, Australian Steel Institute, and the latest Bureau of Meteorology climate data for regional design considerations.

DIY shed kits vs custom-built: what’s right for you?

DIY shed kits (double garage kit / two bay shed)

  • Cheaper upfront; ideal for experienced owner-builders
  • Lead times are often shorter; great for rural sheds NSW and 2 car shed replacements
  • Requires safe lifting, accurate set-out, and compliance paperwork

Custom-built (installed)

  • Engineer-certified plans, faster approvals, and warranty-backed install
  • Easier to meet NCC and AS/NZS wind/bracing requirements
  • Recommended for boundary builds, sloping sites, and wind-rated sheds for cyclonic areas

How to get council approval for your custom shed in WA

Step-by-step (typical for metro councils)

  1. Request site-specific engineering to AS/NZS 1170.2 (wind), AS 4100 (steel), and NCC 2022.
  2. Prepare drawings (site plan, elevations, slab details) and a builder’s quote.
  3. Lodge a building permit application (BA1/BA2 in WA) with energy and drainage notes if required.
  4. Allow 10–25 business days for assessment (varies by council workload).
  5. Schedule inspections (slab pre-pour if required; final completion).

Note: Bushfire-prone sites may trigger AS 3959 bushfire construction rules, especially near vegetation. Boundary walls require fire and stormwater checks. Similar processes apply in VIC, NSW and QLD—terminology and forms vary by state.

Design ideas for a premium double garage

Layouts

  • Two-bay shed with rear roller door to yard
  • Double garage with carport awning for boat/trailer
  • Double garage and workshop with 1–3 windows and PA door
  • 2 storey garage / two story garage concept with mezzanine storage (seek certification)

Specifications

  • Colorbond colours to match house roof and gutters
  • High-cycle roller doors; smartphone openers
  • Anticon or insulated panels to reduce condensation
  • Ridge vent + whirlybirds for hot climates (Perth, inland WA)

Definition — Mezzanine: A partial intermediate floor for storage. Loads, stairs, and head height must be engineer-certified; adding habitable space may change your building classification.

Local case studies

Perth (Region B) — Custom Colorbond double garage in Scarborough

  • Size: 6.5 x 7 m x 3.0 m, gable roof, Colorbond Surfmist
  • Doors: Two 2.7 m high rollers for lifted 4WD; rear PA door to lane