2 Floor Sheds in Australia: Design, Wind Ratings, Colorbond vs Zincalume, Costs & Council Approval

18 Oct Commercial Sheds

Whether you call it a 2 floor shed, 2 storey shed, two story shed, or a storage building with a loft, going vertical is the smartest way to maximise your block. Below we cut the fluff and show you how to spec, price, and approve a premium Colorbond steel shed for Australian conditions.

We cover: steel sheds Perth, custom Colorbond garages Perth, rural sheds NSW, shed builders Brisbane, DIY shed kits, affordable carports for Australian homes, cyclone-rated sheds QLD, barn sheds Victoria, and more.

What is a Two Floor Shed and Who Is It For?

A two floor shed is a Class 10a non-habitable steel building with two usable levels—either a full second storey or a mezzanine/loft for storage. Popular uses include:

  • Workshop shed with mezzanine for parts storage
  • Double garage with upstairs “shed room” or studio (non-habitable unless reclassified)
  • Boat or caravan storage shed with loft for gear
  • Farm machinery storage with an overhead platform for spares
  • Lined sheds for clean, dust-controlled hobby spaces
Definition: Mezzanine
A partial intermediate floor inside the shed, often open to the ground level and designed for storage or light use.
Definition: Portal frame
The primary rigid steel frame (columns and rafters) that carries roof and wind loads.
Definition: BAL rating
Bushfire Attack Level (AS 3959) classification that determines ember and heat protection measures for certain sites.

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

Perth’s long, hot summers and high UV demand roof and wall products that resist fade, heat and corrosion. Most premium builds use BlueScope steel in either Colorbond or Zincalume, profiled as corrugated or Trimdek and fixed with Class 4 screws (AS 3566).

Colorbond vs Zincalume — Which is Better for WA Conditions?

Feature Colorbond Steel Zincalume Steel
Coating Pre-painted over alloy coating (AS/NZS 2728) Aluminium-zinc alloy coating (AS 1397)
Heat reflectance High with light colours; Thermatech helps lower surface temps Good reflectance when clean; dulls over time
Aesthetics Colorbond palette to match new builds and heritage homes Industrial look; paint later if desired
Coastal performance Use Colorbond Ultra near surf coasts (check distance limits) Good, but still observe marine setbacks and maintenance
Best use-case Premium two storey shed or custom-built double garage in Perth Budget-friendly DIY shed kits and farm outbuildings

Pro Tip: Did you know using insulated roof panels can reduce internal shed temperatures by up to 10°C in summer? Pair roof insulation (R2.5+) with breathable sarking and ridge ventilation for the best result.

For energy and heat guidance see the Bureau of Meteorology climate summaries and energy advice at Energy.gov.au, plus CSIRO research on urban heat (CSIRO).

How Do Wind Ratings and Codes Affect a Two Storey Shed?

Every 2 story shed must be engineered to the NCC (BCA) and key Australian Standards:

  • AS/NZS 1170.2 Wind actions (wind regions A–D, terrain category, shielding)
  • AS/NZS 4600 Cold-formed steel structures and AS 4100 Steel structures
  • AS 1562.1 Sheet roof and wall fixing
  • AS 1397/AS/NZS 2728 Material and paint performance
  • AS 3959 Construction in bushfire-prone areas (BAL)
  • AS 2870 Residential slabs and footings (for concrete slabs)

Added 2024 WA wind-rating compliance notes: Most Perth metro sites are non-cyclonic Region A. Typical designs fall into N2–N3 depending on exposure and height. Two floor sheds have higher uplift and lateral loads than single-storey—so expect heavier base plates, extra knee bracing, and closer purlin/girt spacing.

Definition: Importance level
Most sheds are Importance Level 1 (non-critical). Some councils may require IL2. Your engineer will nominate the level.

How to Get Council Approval for Your Custom Shed in WA

Process varies by shire, but you’ll generally need a building permit and may need planning approval if you exceed size/height or encroach setbacks.

  1. Confirm planning: Check R-Codes, setbacks, and max height with your local WA council. Many compliant sheds are exempt from DA.
  2. Engineering: Obtain certified structural drawings for your wind region and soil class.
  3. Apply for Building Permit: BA1 (uncertified) or BA2 (certified). Include site plan, elevations, engineering, specs, and owner/installer details.
  4. Slab/footings: Provide an engineer’s detail to AS 2870 (piers, strip footings or thickened edge slabs).
  5. Inspections: Footings, slab, frame, and final as required by the permit.

council-approved sheds WA tip: Book a pre-lodgement chat—planners often flag height envelopes for two storey storage sheds early, saving weeks.

Other states in brief:

  • QLD: Wind region C/D in the north. “Cyclone kits” require tie-down detailing, sheeting laps, and fastener density per AS/NZS 1170.2.
  • NSW/VIC/SA: Similar NCC process via private certifier or council; BAL may influence cladding, sarking, and ember screens.

Standards and guidance: Master Builders Australia, HIA, and Australian Steel Institute.

2 Storey Shed Design Options and Sizes

Popular footprints for Australian blocks include 6×9 m, 7×12 m, and 9×15 m with wall heights from 3.6 m to 5.4 m. A mezzanine can span a bay or run full-length for a true two floor shed.

Roof types

  • Gable roof: Classic look, great for rainfall; add eaves for shade.
  • Skillion roof: Modern, cost-effective, and perfect for solar orientation.

Frames and floors

  • Portal frames in cold-formed C/Z sections sized for your wind region (N2–N3 or C2–C3).
  • Mezzanine joists: PFC or cold-formed sections; typical storage rating 2.0–3.0 kPa (engineer to confirm).
  • Stairs and balustrades to NCC Vol 2, Part 3.9.1.

Doors and access

  • Roller doors (manual or motorised), high-lift tracks for mezz clearance.
  • PA doors with compliant landing; security mesh options.
  • Vehicle-friendly bays for farm machinery storage or a custom-built double garage in Perth.

Cladding, lining and comfort

  • Colorbond cladding with Anticon blanket and R2.5–R3.2 roof insulation.
  • Whirlybirds or ridge vents; optional skylight/clearlite strips.
  • Lined sheds (ply or plasterboard) for a dust-free “shed room” or hobby space. Note: Habitable use requires a different building class and extra compliance.

Related options and keywords: steel sheds Perth, custom carports Melbourne, shed kits Adelaide, barn sheds Victoria, industrial steel buildings Australia, affordable carports for Australian homes, workshop shed with mezzanine, double garage kits, machinery sheds WA, boat shed Gold Coast, caravan storage shed, rural sheds NSW.

custom Colorbond garages Perth are often combined with a mezzanine to create a two story storage shed footprint without increasing site coverage.

Case Studies: Built for Australian Conditions

Case 1 — Two Floor Shed, Perth WA (Non-cyclonic N2)

  • Size: 7×12 m, 5.0 m eave height, gable 15°
  • Structure: Colorbond wall/roof, Z-purlins/girts, braced bays
  • Upper level: 30 m² mezzanine (3.0 kPa), ply floor
  • Features: R2.5 roof insulation, ridge vent, two 3.0 m roller doors
  • Compliance: NCC Vol 2 Class 10a, AS/NZS 1170.2 N2, BAL-12.5 (ember mesh)

Case 2 — Cyclone-Rated Two Storey Workshop, Townsville QLD (Region C)

  • Size: 9×12 m, 5.4 m wall height, skillion 5°
  • Structure: Heavier portal frames, increased hold-down bolts, dense screw pattern
  • Upper level: Full-length mezzanine for parts storage
  • Doors: Wind-locked roller doors
  • Compliance: AS/NZS 1170.2 Region C, tie-down schedules and sheeting laps per engineer

cyclone-rated sheds QLD: Expect upgraded fasteners, door hardware and bracing for pressure and debris.

Case 3 — Rural Two Storey Storage Shed, Central West NSW

  • Size: 6×9 m, gable roof, Zincalume cladding
  • Upper level: 18 m² loft for seasonal storage
  • Add-ons: 3 m lean-to for tractor parking
  • Compliance: AS/NZS 1170.2 N3 due to exposure; BAL-LOW

Costs, Lead Times and What to Budget in 2025

Indicative only (site-specific and market-dependent):

  • Two floor shed kits (frame, cladding, fixings): typically from the mid-$20k for compact footprints; larger custom Colorbond builds with full mezzanines can exceed $70k–$120k.
  • Concrete slab and footings: budget allowance based on thickness, edge beams and soil class.
  • Install: varies by region, access, and wind rating. Cyclonic installs attract premiums.
  • Lead times: 4–10 weeks from sign-off to delivery; longer in peak periods.

Market context: See HIA’s latest Outdoor Structures and Home Improvement insights and the Australian Steel Market Outlook for steel price trends (HIA).

5-Step Buying Guide for Custom Sheds in Australia

  1. Scope your use: parking vs workshop vs “shed room” with lined walls.
  2. Pick materials: Colorbond for premium look and heat performance; Zincalume for value.
  3. Engineer for location: wind region (N or C/D), BAL, soil class, terrain category.
  4. Plan approvals early: site plan, elevations, engineering, setbacks and height.
  5. Lock in ventilation and insulation: insulated roof panels or blanket, vents, and door seals.

FAQs: Two Storey Sheds in Australia

Can I live in my two storey shed?

Not without a change of building classification and extra compliance (fire, energy, amenity). Standard sheds are Class 10a non-habitable.

Are mezzanines safe for heavy storage?

Yes—if engineered. Specify the intended load (kPa) and have the mezzanine designed and certified accordingly.

Do I need insulation?

Highly recommended for Perth and inland heat. Pair roof and wall insulation with ventilation for year-round comfort.

What wind rating do I need?

Your engineer will nominate N or C/D region, terrain and shielding. Perth is generally N2–N3; northern QLD often Region C or D.

Colorbond or Zincalume?

Colorbond for premium appearance and heat reflection (especially light colours). Zincalume for cost-effective rural builds. Both use BlueScope substrate and meet Australian Standards.

Why Choose a Local, Code-Literate Shed Team

  • Engineered designs to AS/NZS 1170.2, AS/NZS 4600 and NCC
  • Custom layouts: two story storage shed, double garage with loft, machinery sheds WA
  • Help with permits and council-approved sheds WA paperwork
  • Quality fixings (Class 4), door hardware and ventilation to suit your climate

References and Further Reading

Need a quote for a two storey shed or a custom Colorbond double garage in Perth? Ask about engineered kits, install, and council approvals across WA, NSW and QLD.