Barn Sheds with Mezzanine Floors in Australia: 2025 Guide, Pricing, Approvals and Build Tips
For Australian homeowners, renovators and property investors, a Colorbond steel barn with a compliant mezzanine can double usable floor area without expanding the slab. Whether you’re planning an American barn for farm machinery storage in regional NSW, a custom-built double garage in Perth with an upper loft, or cyclone-rated sheds in QLD, this guide distils what the top suppliers offer—and goes deeper on approvals, wind ratings, and design choices for our climate.
Why choose a barn shed with a mezzanine in Australia?
A mezzanine floor dramatically increases the usable space in your barn shed, making it ideal for a wide range of purposes. In fact, mezzanine floors are a popular feature in modern barndominium designs across Australia.
Adding a mezzanine floor is a great way to maximize space in your barn shed. Quaker Barn sheds are particularly well-suited for mezzanine designs, providing ample headroom and flexible layout options.
For additional convenience and a modern touch, sliding barn doors for barn can be installed, allowing for efficient use of space both upstairs and downstairs in your mezzanine barn shed.
If you’re planning to include multiple storeys in your barndominium, explore our extensive collection of barndominium floor plans tailored for Australian lifestyles.
- Two levels, one footprint: mezzanine floors add 30–60% more usable space for storage, offices, studio or guest overflow.
- Value-add: a well-specified custom Colorbond garage Perth with mezzanine can boost resale appeal and functionality.
- Future-ready: start as a workshop; fit out the upper level later as kids’ retreat or archive room.
- Design versatility: American barn style with high centre bay and lean-to wings, or modern gable with internal stairs.
What Are the Best Shed Materials for Perth’s Climate?
Perth’s hot summers, coastal air and UV exposure demand durable cladding and roofing. Most premium steel sheds Perth are built in Colorbond or Zincalume on cold-formed steel frames (C sections/Z purlins) with high-tensile bolts and cyclone-rated fasteners where required.
Colorbond vs Zincalume — Which Is Better for WA Conditions?
| Criteria | Colorbond Steel | Zincalume |
|---|---|---|
| Finish | Pre-painted, baked-on colour range (Classic + Matt) | Galvalume metallic finish |
| Corrosion resistance | Excellent; Colorbond Ultra available for severe marine | Excellent; may show patina near coasts over time |
| Heat reflectance | High for light colours; reduces heat gain | Very high reflectance in bare metallic finish |
| Aesthetics | Architectural colours suit modern Aussie homes | Rural/industrial look |
| Typical cost (cladding/roof) | $$ (premium) | $ (more economical) |
| Best for | Residential blocks, coastal suburbs, matching Colorbond fencing/roof | Sheds set back from coast, farm structures, budget-savvy builds |
For Perth metro and coastal WA, most buyers choose Colorbond for longevity and aesthetics. Inland/regional WA projects often mix Colorbond fascia with Zincalume roof for budget control.
How do mezzanine floors in barn sheds work?
A shed mezzanine is typically a raised floor platform built off the steel portal frame using engineered joists (cold-formed C-purlins or LVL), fixed to cleats or RHS beams. Design must satisfy the National Construction Code (NCC 2022) and relevant Australian Standards.
- Typical clear heights: 2.4–3.6 m under-mezzanine; 2.1–2.7 m above (depending on ridge height and roof pitch).
- Stairs/guarding: Must comply with AS 1657 for stairs, platforms and guardrails; consider lockable stair access for safety.
- Flooring: Tongue-and-groove structural flooring or steel deck with sheet underlay; specify acoustic underlay if near bedrooms.
- Openings: Include a safety loading gate or pallet gate to safely load heavy items to the mezzanine.
Approvals and Wind Ratings by State (NCC/AS/NZS)
How to Get Council Approval for Your Custom Shed in WA
In WA, sheds generally need a Building Permit under the Building Act 2011. Steps:
- Site plan and elevations: Nominate setbacks, heights, stormwater, and finish (Colorbond/Zincalume).
- Engineering: Certified drawings to AS/NZS 1170.2 (wind), AS/NZS 4600 (cold-formed steel) and AS 4100 (steel structures), plus slab to AS 3600.
- Building surveyor: Obtain a Certificate of Design Compliance (CDC).
- Submit BA1 (certified application) to your local government with fees; or BA2 (uncertified) if your surveyor is in-house.
- Allow 10 business days typical for a certified permit. Some metro councils may request neighbour consultation if within residential codes.
Added 2024 WA wind-rating compliance notes: Most Perth suburbs are Region A (non-cyclonic) per AS/NZS 1170.2; coastal fringes and exposed hillsides can increase wind class. Your engineer will assign Terrain Category, Topographic Multiplier (Mt) and Shielding (Ms) in the design certificate.
Cyclone-rated sheds in QLD
North and coastal Queensland commonly fall in Wind Regions C and D. Specify cyclone-rated sheds QLD with:
- Increased hold-downs, strap bracing and cyclonic roof battens
- Higher capacity portal frames, purlins, and fasteners (e.g., cyclonic screws)
- Door/wind-lock kits and wind-rated roller doors
Expect higher steel weights and cost, but far greater resilience in severe weather as observed by the Bureau of Meteorology cyclonic risk profiles.
Coastal NSW, BAL bushfire zones and corrosion
- Rural sheds NSW near the coast benefit from Colorbond Ultra or additional coating systems.
- In BAL-affected areas, specify ember-resistant vents and compliant glazing; check local DCPs.
- Consider stainless fixings within 1 km of breaking surf to reduce tea-staining and corrosion.
Barn Kits vs Custom-Built: Which Suits You?
Australian buyers often weigh DIY shed kits against turnkey builds. Both can deliver premium results if engineered and installed correctly.
DIY Kit vs Custom-Built Comparison
| Aspect | DIY Barn Kits | Custom-Built by Licensed Installer |
|---|---|---|
| Cost | Lowest upfront (sweat equity) | Higher, includes labour and project management |
| Complexity | Best for straight, non-cyclonic sites | Suited to sloping sites, high wind, BAL or tight access |
| Time | Depends on skills and crew availability | Predictable timeline, fewer delays |
| Approvals | You coordinate surveyor and permits | Builder handles design certification and council |
| Finish | Great for DIY shed kits with simple mezzanine | Premium finish, integrated fit-out, electrical and plumbing coordination |
If you need a council-approved shed WA in a coastal suburb, or a cyclone-rated shed QLD, custom-built is usually smoother.
Roof Profiles for Barns: Gable vs Flat (Skillion)
Most barns use a gable centre bay with lean-tos, but some sites prefer a single-slope skillion for modern lines and easy solar PV placement.
Flat/Skillion Roof vs Gable Roof
| Criteria | Flat/Skillion | Gable (Traditional Barn) |
|---|---|---|
| Looks | Modern, minimalist | Classic barn, higher centre bay |
| Mezzanine headroom | Limited at low pitch; better at higher wall heights | Excellent under ridge for upper floor |
| Drainage | One-way fall; bigger box gutters | Two-way fall; standard gutters |
| Wind performance | Good when engineered; less eave overhang | Excellent; classic portal frame action |
| Solar PV | Great orientation flexibility | Good; depends on pitch and aspect |
Loads, Slabs and Fit-out
- Slab: Common thickened-edge raft slabs 100–150 mm with footings to engineering spec (AS 3600). For hoists or heavy racking, thicken local pads.
- Mezzanine loading: 2.5 kPa is typical for general storage; heavy archives or gym setups may need 3–5 kPa. Confirm with your engineer.
- Doors: Wind-rated roller doors or sectional doors sized for caravan and boat storage.
- Insulation: Blanket or panel insulation improves comfort and reduces condensation; consider vapour barriers in cool climates.
- Services: Pre-plan GPOs, data, plumbing, and lighting to avoid rework once the mezzanine is in.
Real Build Examples (Case Studies)
Perth — Custom Colorbond Barn with Mezzanine (9 m × 12 m)
- Use: Custom-built double garage in Perth with a 30 m² mezzanine office
- Spec: Colorbond Matt Monument cladding, insulated roof blanket, 2.7 m under-mezz clearance
For those considering alternative materials, our wooden barn guide offers expert tips and inspiration for timber barn construction in Australia.