Shed Plans Australia PDF: 2025 Guide to Colorbond Steel Sheds, Carports, Approvals and Costs

27 Oct Custom Sheds

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What Are the Best Shed Materials for Perth’s Climate?

Perth summers are hot and dry, with coastal sites facing salt-laden winds. For a custom-built double garage in Perth or steel sheds Perth, most homeowners choose Colorbond cladding and roofing over Zincalume in coastal or urban environments due to superior paint performance and colour retention.

Quick definitions

  • Colorbond: Painted, pre-finished steel by BlueScope with baked-on coating, available in Australian colours and Ultra/SS for marine zones.
  • Zincalume: Aluminium-zinc alloy coated steel (e.g., AZ150). Bare-metal look; great value inland.
  • Wind rating: The design pressure your shed must resist per AS/NZS 1170.2 or AS 4055; includes regions A–D (cyclonic in C–D).

Colorbond vs Zincalume — Which Is Better for WA Conditions?

Criteria Colorbond Zincalume
Coastal resistance Use Colorbond Ultra/SS within ~200–400 m of surf; strong paint system for salt spray Not recommended in marine splash zones
Heat reflectivity Light colours reduce heat gain; pairs well with sarking/Anticon High reflectivity initially; may dull over time
Aesthetics Wide colour range; premium look for custom Colorbond garages Perth Bare-metal, industrial look
Cost Higher upfront Lower upfront
Best use Residential sheds, coastal, architectural projects Inland rural sheds and farm machinery storage

Related: Colorbond vs Zincalume comparison, corrosion categories (C1–C5), and affordable carports for Australian homes.

Free Shed Plans Australia PDF: What’s Inside

This guide doubles as a printable shed plans Australia PDF to help you brief engineers and builders. It’s ideal for DIY shed kits, rural sheds NSW, or custom carports Melbourne.

  • Plan set: Floor plan, elevations, sections, portal frame set-out
  • Footing and slab schedule: Edge thickenings, piers, hold-down anchors
  • Member sizing: Columns, rafters, C-purlins and Z-girts
  • Cladding/roofing: Colorbond or Zincalume profile, gauge, and fixings
  • Door schedule: Roller doors (windlock), PA doors, sliding barn doors
  • Accessories: Vermin flashing, sarking/Anticon, insulation, gutters/downpipes

Example standard sizes and notes

Type Nominal size (WxL) Roof Wind region Notes
Single garage 3.6 m x 6.0 m Gable 15° A, B 100 mm 25 MPa slab, M12 chemset anchors
Double garage 6.0 m x 7.0 m Gable 10° A, B Windlock roller doors, Anticon 60 mm
Rural machinery shed 12.0 m x 6.0 m Gable 10° A, B, C (engineered) Open bays; increased bracing; hot-dip anchors
Skillion carport 6.0 m x 6.0 m Skillion 3° A, B, C (engineered) Galv RHS posts; concealed box gutter option

All sample plans must be finalised by an engineer to AS/NZS standards and NCC 2022. Wind, terrain, and shielding may change member sizes.

How to Choose the Right Shed for Your Site

1) Start with wind region, terrain and shielding

Australia uses wind Regions A–D (per AS/NZS 1170.2). Region C and D are cyclonic (many coastal QLD/NT sites). Terrain Category 2 (TC2) is typical for suburbs. Shielding from nearby buildings reduces pressures. Added 2024 WA wind-rating compliance notes: coastal WA sites need careful check of Region B vs C boundary, local topography, and corner zone fixings.

Wind design cheat sheet

  • Standards: NCC 2022, AS/NZS 1170.2 (wind loads), AS/NZS 4600 (cold-formed steel), AS 4100 (steel structures)
  • Ensure cyclone tie-downs for wind-rated sheds for cyclonic areas
  • Use windlock roller doors and extra bracing in corner and edge zones

2) Consider corrosion and coastal exposure

Marine zones often require Colorbond Ultra/SS, heavier coatings, stainless fixings, and additional vermin flashing to seal edges. Inland farm machinery storage can use Zincalume AZ150 with galv fixings.

3) Pick the roof form

Roof type Pros Cons Best for
Gable (10–15°) Strong, great drainage, classic look More ridge/valley detailing Garages, American barn kits Australia
Skillion (2–5°) Modern profile, simple structure Higher uplift on leading edge Carports, lean-tos, coastal minimal design

4) Doors, access and height

For caravans or boats, set eave height at 3.0–3.6 m. Choose windlocked roller doors in cyclonic or exposed sites. Add a 910 mm PA door for safety egress.

5) Thermal comfort and condensation

Use sarking plus Anticon blanket or insulated panel roofing. Ventilation (ridge and eave vents) helps in QLD humidity and Perth heat.

Pro Tip: Using insulated roof panels can reduce internal shed temperatures by up to 10°C in summer. See energy efficiency guidance from Energy.gov.au.

Council Approvals and Building Codes by State

How to Get Council Approval for Your Custom Shed in WA

  1. Confirm R-Codes and local planning overlays (setbacks, site coverage, height).
  2. Get wind region/terrain from a WA engineer or council mapping.
  3. Prepare a certified engineering package to AS/NZS 1170.2 and AS/NZS 4600.
  4. Lodge BA2/BA3 forms (certified) with site plan, elevations, structural details.
  5. Check bushfire (BAL) if near vegetation; add ember protection as required.

Ask for council-approved sheds WA designs to shorten approval time.

NSW: DA or Complying Development (CDC)

Many rural sheds NSW qualify for CDC if they meet Exempt/Complying criteria (size, height, setbacks). Otherwise, submit a DA with engineering and BASIX if applicable.

QLD: Cyclone regions and Form 15/16

In Region C/D, always specify cyclone-rated sheds QLD with certified tie-down schedules, door windlocks, and bracing. You’ll need Form 15 (design) and Form 16 (inspection).

VIC: Bushfire BAL and overlays

Check BAL rating for flame zone or ember exposure. In BAL 29 and above, consider non-combustible cladding and ember seals. For custom carports Melbourne, verify eave projection and stormwater to legal point of discharge.

Design and Engineering Specs to Look For

  • Frames: Cold-formed steel portal frames to AS/NZS 4600; hot-dip galv baseplates.
  • Members: C-purlins and Z-girts sized to wind pressures; check lap lengths and bridging.
  • Footings/slabs: Typical 100 mm 25 MPa slab with N12 bars; pier or pad footings for high loads; M12–M16 chemset anchors.
  • Cladding: 0.42–0.48 BMT wall sheets; 0.48–0.60 BMT roofs in high wind/cyclone zones.
  • Fasteners: Class 4 screws in coastal areas; stainless where specified.
  • Open-front sheds: Extra bracing/columns due to uneven pressures.
  • Doors: Windlock roller doors; sliding barn doors for wide bays.
  • Moisture: Sarking and Anticon, sealed penetrations, vermin flashing.

Real Build Examples Across Australia

Perth: Custom-built double garage in City Beach

  • Size: 6.5 x 7.0 m, gable 10°, Colorbond Ultra (Surfmist)
  • Region B coastal; Class 4 fasteners; Anticon 60 mm
  • Outcome: 5–7°C cooler interior; corrosion warranty compliance

NSW Central West: Rural machinery shed

  • Size: 12 x 9 m with 4.2 m eaves, 3 open bays
  • Zincalume roof/walls, Z-girts, gravel floor with concrete footings
  • Outcome: Cost-effective storage for tractors and hay sheds add-on

Far North QLD: Cyclone-rated carport

  • Size: 6 x 6 m skillion; Region C tie-downs and windlock doors avoided by open sides
  • RHS posts with bolted knee braces; 0.48 BMT roof
  • Outcome: Passed engineering and council first go

Cost Guide 2025: DIY Kit vs Custom-Built

Prices vary by wind rating, height, doors, and site works. Use these ballparks to plan, then obtain an engineered quote.

Type DIY Kit (excl. slab) Installed (incl. slab) Notes
Single garage (3.6 x 6 m) $3,500–$6,500 $9,500–$15,000 Region A/B; add 10–25% for coastal/cyclone
Double garage (6 x 7 m) $6,500–$11,500 $15,000–$28,000 Colorbond increases cost vs Zincalume
Rural shed (12 x 6 m) $10,000–$20,000 $28,000–$55,000 Open bays cheaper; enclosed = doors/windows
Carport (6 x 6 m) $2,200–$5,500 $7,500–$14,000 Cyclone detailing costs more

Note: Material and labour costs continue to reflect volatility noted in the 2024 Australian Steel Market Outlook and the 2024 HIA Outdoor Structures report.

Frequently Asked Questions

Can I build a shed without council approval?

Sometimes. Small sheds/carports may be exempt or complying. Check local size/height/setback rules and obtain engineering where required.

Do I need cyclone rating in SE QLD?

Parts of coastal QLD are Region C. Get your exact wind region and design to AS/NZS 1170.2 with cyclone tie-down schedules.

Is a 100 mm slab enough?

Often yes for domestic garages. Heavier loads or poor soils may require thicker slabs, beams or piers. Engineer sign-off is essential.

Colorbond Ultra or standard Colorbond?

Use Ultra or Stainless near surf or severe marine environments. Standard Colorbond suits most inland and suburban sites.

What’s the best roof for a carport?

Skillion for modern look and simpler build. Gable for stronger drainage and classic styling.

Can I add a mezzanine later?

Yes, if your portal frames and footings are designed for the extra load. Plan ahead for stair location and headroom.

5-Step Buying Guide for Custom Sheds in Australia

  1. Define use: vehicles, farm machinery storage, workshop, or home business.
  2. Confirm site data: wind region, terrain, shielding, BAL, soil class.
  3. Choose materials: Colorbond vs Zincalume, roof type, insulation, doors.
  4. Get engineering and a detailed quote: members, fixings, tie-downs, slab.
  5. Apply for council approval and book installers or plan your DIY shed kits timeline.

Resources and Standards

Keyword clusters for better planning

  • Location: steel sheds Perth, custom Colorbond garages Perth, rural sheds NSW, custom carports Melbourne
  • Technical: Colorbond vs Zincalume comparison, wind-rated sheds for cyclonic areas, portal frame design, C-purlins Z-girts, NCC 2022 compliance
  • Use cases: farm machinery storage, American barn kits Australia, hay sheds, skillion roof carport, double garage 6×6
  • Compliance: council-approved sheds WA, cyclone-rated sheds QLD

Disclaimer: This article provides general guidance only. Always obtain site-specific engineering and council approvals before construction.