When Dave and Sarah purchased a 2-acre block in Mundijong in early 2025, the first thing on their list — before the house renovation, before the landscaping, before anything else — was a proper workshop. Dave is a qualified mechanic who restores classic cars on weekends, and Sarah runs a small pottery studio. They needed a big, versatile space that could handle both.
This is the story of how we took their empty block from bare dirt to a fully kitted-out 18x12m dream workshop — and the lessons learned along the way that might help if you’re planning a similar build.
The Brief
Dave and Sarah came to us with a clear list of requirements:
- 18m x 12m footprint with 4.2m wall height (to fit a vehicle hoist)
- Fully enclosed with insulation throughout
- Three roller doors — one high-clearance for the hoist bay
- A partitioned section for Sarah’s pottery studio with natural light
- Mezzanine level for storage and a small office
- Full electrical fit-out with three-phase power
- Concrete slab with vehicle-grade finish in the workshop bays
They’d already spoken to two other shed companies. One quoted over the phone without visiting the site. The other visited but quoted a non-engineered kit that wouldn’t have met the wind rating for the area. Dave and Sarah found us through a recommendation from a mate in Helena Valley whose shed we’d built the previous year.
Site Assessment and Design
The Mundijong block had a couple of challenges. The site had a gentle slope of about 600mm across the building footprint, which meant earthworks and a split-level slab would be needed. There was also an easement along one boundary that affected where we could position the shed.
We visited the site, took measurements, and prepared a full CAD design showing the shed from multiple angles, including the mezzanine layout and where the internal walls would go for Sarah’s studio. Being able to see the design in 3D before committing was a big deal for Dave and Sarah — they made several changes to the internal layout based on the model that they wouldn’t have picked up from flat plans alone.
“Seeing our shed in 3D before it was built was amazing. We moved Sarah’s studio to the south side for better light, and added an extra roller door we hadn’t originally planned. Both changes made a huge difference to the finished result.” — Dave, Mundijong
Approvals and Permits
Mundijong falls within the Shire of Serpentine-Jarrahdale, and the approval process was relatively straightforward for a rural-zoned property of this size. We submitted:
- Engineer-certified structural plans
- A building permit application
- Site plan showing setbacks and easement clearance
- BAL assessment (the property is in a bushfire-prone area)
The building permit was approved in just under three weeks. We’ve found the Shire of Serpentine-Jarrahdale generally processes permits efficiently, similar to our experience with the City of Swan for builds in Bullsbrook, Henley Brook, and Ellenbrook.
The Build
Total construction time from site preparation to handover was 8 weeks. Here’s how the timeline broke down:
Week 1–2: Site preparation. Earthworks to level the building pad, compaction, and formwork for the concrete slab. The slab included a thickened edge and vehicle-grade reinforcement in the workshop bays, plus a smooth-trowelled finish in Sarah’s studio section.
Week 3: Steel frame erection. Our crew had the entire C-section steel frame up in four days. The 4.2m wall height and mezzanine structure required heavier gauge steel than a standard shed, but this is where engineering certification matters — everything is calculated for the specific wind region (N2 for Mundijong) and the structural loads.
Week 4–5: Cladding, roofing, and roller doors. Dave chose Colorbond Monument for the walls and Basalt for the roof — a combination we’ve been using a lot lately for customers across Mundijong, Byford, and the surrounding area. It gives a modern, professional look that works beautifully against the bush backdrop. Three roller doors were installed, including one at 3.6m height for the hoist bay.
Week 6: Mezzanine and internal walls. The mezzanine covers about a third of the floor area and is accessed by a steel staircase. We framed the internal partition wall for Sarah’s studio with acoustic insulation to keep the workshop noise out of her creative space.
Week 7–8: Insulation, electrical, and finishing. Full blanket insulation throughout the roof and walls, plus the three-phase electrical fit-out by our electrician. Dave had us install extra power points at workbench height throughout the workshop — something we always recommend after years of hearing customers in Darlington, Sawyers Valley, and Mundaring say they wished they’d added more during the build.
The Result
The finished workshop is, in Dave’s words, “better than I imagined.” The mezzanine office overlooks the main workshop floor through an internal window. Sarah’s pottery studio gets beautiful south-facing natural light through three large windows. And the vehicle hoist sits comfortably under the high-clearance roller door with room to spare.
Total project cost came in at just over $85,000 including the slab, full electrical, and insulation — right on the estimate we’d provided at the quoting stage. No surprise additions, no scope creep. That’s something we take pride in with every build, whether it’s an $8,000 garage in Midland or an $85,000 workshop in Mundijong.
1. Always get an on-site assessment — phone quotes miss critical details. 2. Engineer certification isn’t optional — it protects your investment and insurance. 3. Think about power points and lighting early — it’s 10x cheaper during the build than after. 4. CAD design pays for itself in avoiding costly changes during construction.
Planning something similar? Whether you’re in Mundijong, Byford, Darlington, or anywhere across WA, we’d love to chat about your project.