4 Car Garage Shed: Custom Colorbond Garages Built for Australian Conditions
Excerpt: Looking to fit four vehicles, a workshop and storage without compromising street appeal? This guide covers 4 car garage shed sizing, Colorbond vs Zincalume, WA/QLD wind ratings, council approvals, pricing, and whether to go DIY kit or turnkey install—plus real Aussie case studies and a quick buying checklist.
What is a 4 car garage shed?
A 4 car garage shed (also called a 4 car garage, 4-bay garage, or 4 stall garage) is a custom steel building designed to house four vehicles with room for tools, bikes and a workshop bay. In Australia, most premium builds use Colorbond steel cladding over galvanised portal frames, engineered to AS/NZS standards and local wind regions.
Typical inclusions: B&D-style roller doors or sectional doors, personal access (PA) door, vermin flashings, gutters and downpipes, anti-condensation blanket or insulation, and a 100–120 mm concrete slab with thickened edge beams.
- Ideal for: family fleets, project cars, caravan/boat storage, farm machinery storage, or combining a garage and hobby workshop.
- Scalable: Many clients expand to a 5 or 6 car garage using additional bays or higher eaves for 4WDs with roof racks.
What Are the Best Shed Materials for Perth’s Climate?
For a custom-built double or 4-bay garage in Perth and across WA, durability and heat management are critical.
- Cladding: BlueScope Colorbond (including Colorbond Matt) resists UV and heat; coastal sites may upgrade to Ultra for corrosion zones.
- Frames: Galvanised cold-formed steel designed per AS/NZS 4600; hot-dip galvanising boosts coastal performance.
- Fasteners: Class 4 screws for coastal/corrosive environments.
- Roof: High-tensile steel sheeting; consider 15° gable for ventilation or skillion for modern streetscapes.
Added 2024 WA wind-rating compliance notes: Many Perth suburbs are N2–N3; coastal and hill sites may require N4. Check your site-specific wind classification and terrain category in engineering.
What size 4 car garage shed should I choose?
Clear-span designs maximise parking space and manoeuvrability. Common sizes for a four-bay car shed:
- 12 m (L) x 7.5 m (W) x 3.0 m eave, 4x 3.0 m roller doors
- 12 m x 9 m x 3.2 m eave, 4x 3.0–3.3 m doors, workshop bench at rear
- 15 m x 7.5 m x 3.6 m eave for 4WDs with racks or a boat
Door options: individual roller doors, two large sectional doors, or a combination with one high-clearance bay for a caravan. Add PA doors and windows with awnings for cross-flow ventilation.
Flat vs Gable vs Skillion: Which roof suits a 4-bay garage?
| Roof Style | Pros | Considerations | Best for |
|---|---|---|---|
| Gable (10–20°) | Classic look, good runoff, supports ridge vents | Slightly taller ridge; may affect height limits | Suburban homes, rural sheds NSW and VIC |
| Skillion (single pitch) | Modern aesthetic, easy solar PV orientation | Wind uplift needs careful detailing in N3/C regions | Custom Colorbond garages Perth, contemporary builds |
| Flat (low pitch) | Lower profile, simpler guttering | Strict drainage detailing; not ideal for heavy leaf areas | Compact lots, carports Melbourne infill |
Colorbond vs Zincalume — Which is better for WA conditions?
| Feature | Colorbond | Zincalume |
|---|---|---|
| Finish | Painted, wide colour range incl. Matt | Metallic silver-grey (AZ150 coating) |
| Heat reflectance | Solar-reflective colours reduce heat gain | Good emissivity; add insulation for comfort |
| Coastal performance | Colorbond Ultra for severe marine | May require higher maintenance near surf |
| Cost | Slightly higher | Budget-friendly |
| Street appeal | High — matches home palette | Industrial look |
Both are genuine BlueScope steels with manufacturer warranties when installed to specification. For coastal and high-UV areas in WA and QLD, Colorbond Ultra or high-performance coatings are recommended.
How much does a 4 car garage shed cost in Australia?
As a 2024–2025 guide (materials and labour vary by region):
- DIY kit (Colorbond cladding, engineered): $19,000–$32,000
- Installed shell (slab extra): $28,000–$45,000
- Turnkey (engineering, council, slab, build): $45,000–$75,000+
Drivers: wind rating (N2 vs N3/C2), height, door automation, insulation, coastal upgrades and slab thickness. According to the 2024 HIA Outdoor Structures and Home Improvement Report, material volatility and labour shortages continue to affect timelines and pricing across steel sheds in Perth, Brisbane and regional centres.
How to Get Council Approval for Your Custom Shed in WA
Step-by-step approvals and engineering
- Confirm zoning/overlays and setbacks with your local council or certifier.
- Obtain site-specific engineering to AS/NZS 1170.2 (wind), AS 4100/AS/NZS 4600 (steel), NCC Volume Two, and AS 3959 if in a bushfire area (BAL assessment).
- Lodge a building permit (BA application in WA) with drawings, engineering, energy/insulation notes and stormwater plan.
- Book footing/slab inspections where required; pour a 25–32 MPa slab 100–120 mm with thickened edge beams and SL72 mesh as specified.
- Final inspection and occupancy/use sign-off.
council-approved sheds WA need compliant height, boundary setbacks and on-site stormwater disposal. In QLD’s coastal north, insist on cyclone-rated sheds QLD with C2/C3 engineering, extra hold-downs and cyclonic-rated roller doors.
DIY Shed Kits vs Turnkey Installed
| Option | Pros | Considerations | Who it suits |
|---|---|---|---|
| DIY shed kits | Lower cost, flexible timing, rewarding for handy owners | Requires tools, lifting gear, construction know-how; more time | Owner-builders, rural sites with tradie mates |
| Supply & install (shell) | Faster, professional finish, warranty-backed | Slab and approvals may be separate | Busy homeowners, investors |
| Turnkey (council + slab + build) | One contract, minimal hassle, predictable timeline | Highest upfront cost | Time-poor owners, premium projects |
Thermal Comfort, Ventilation and Energy
- Insulation: Anticon blanket under roof sheets, wall batts or insulated sandwich panels in hot climates (Perth, Adelaide).
- Ventilation: Ridge vents, whirlybirds, and louvred windows; cross-ventilation keeps workshop temps down.
- Solar and power: Pre-wire conduits; skillion roofs suit PV arrays; LED high-bays for efficient lighting.
Pro Tip: Did you know using insulated roof panels can reduce internal shed temperatures by up to 10°C in summer? Combine with light Colorbond colours and ridge ventilation for best results.
Build Examples from Around Australia
Perth, WA — custom Colorbond garages Perth
12 m x 9 m x 3.3 m gable, Colorbond Monument walls with Surfmist roof, 4x 3.0 m automated roller doors, Anticon 60 mm, 120 mm slab with thickened edges, N3 wind classification. Completed as a turnkey install, including stormwater to 90 mm downpipes and soak wells.
Townsville, QLD — Cyclone-rated four-bay
12 m x 7.5 m skillion, C2 wind region engineering, cyclonic door kits, extra hold-down brackets, screw patterns per AS/NZS 1170.2. Zincalume cladding with internal foil blanket; mesh screens to reduce debris ingress during storms.
Regional NSW — Rural shed with mixed-use
15 m x 9 m American barn style: 4 car garage bays plus tractor bay. Rural sheds NSW spec with higher eaves, PA doors, vermin-proofing, and water tank capture from large roof area.
Keyword clusters we service
- Location: steel sheds Perth, custom carports Melbourne, rural sheds NSW, Brisbane skillion carports, Adelaide garages
- Technical: Colorbond vs Zincalume comparison, wind-rated sheds for cyclonic areas, BAL bushfire garages, ShedSafe accredited designs
- Usage: farm machinery storage, garage workshop fitout, affordable carports for Australian homes, DIY shed kits, American barn sheds
5-Step Buying Guide for Custom Sheds in Australia
- Scope your use: four vehicles, boat bay, or workshop? Decide eave height and door clearances.
- Select materials: Colorbond colourways, Ultra/coastal upgrades, Class 4 fasteners.
- Engineering: Confirm wind region (N2–N4 or C2/C3), terrain category, footings and slab spec.
- Approvals: Prepare site plan, drainage, energy/insulation notes; lodge permit with stamped engineering.
- Build program: Choose DIY vs installed, book slab pour, confirm lead times and door automation.
FAQs
What wind rating do I need?
Most metro sites are N2–N3. Elevated, escarpment or coastal exposures may require N4. Northern QLD often requires C2/C3. Your engineer will verify per AS/NZS 1170.2 and the Bureau of Meteorology wind region map.
Can I turn a 4 car garage into a 6 car garage later?
Yes. Use modular portal frames and allow slab dowels for future bays. Ensure roof drainage and downpipe capacity can be extended.
Do I need a termite barrier under the slab?
In many regions, yes. Chemical or physical barriers at slab penetrations protect the garage and any future habitable fitout.
Roller doors or sectional doors?
Roller doors are robust and cost-effective; sectional doors offer better sealing and architectural styles. Both can be wind-rated for cyclonic areas.
Technical Spec Notes and Standards
- Design actions: AS/NZS 1170 series (wind, dead/live loads)
- Steel design: AS 4100 (hot-rolled), AS/NZS 4600 (cold-formed)
- Bushfire: AS 3959 (BAL), where applicable
- NCC Volume Two compliance, energy and condensation management
- BlueScope material warranties when installed to spec
Popular Upgrades
- Automation for 4x doors, smartphone control
- Workshop fitout: benches, 15 A GPOs, compressed air lines
- Skylights or translucent polycarbonate panels
- Ridge vent and whirlybirds for passive cooling
- Internal lining to create a hobby space or home gym
Why Australian owners choose our 4 car garage sheds
- Site-specific engineering for wind and terrain
- BlueScope Colorbond and Zincalume with manufacturer-backed warranties
- Local council know-how for faster approvals
- Options from DIY shed kits to complete turnkey installs