What size shed actually fits a Narre Warren home?
Start with what must move through the door, where people need to stand, and how a vehicle reaches the opening. A dimension that looks generous on a brochure can feel cramped once door tracks, benches, shelving and portal columns take their share.
For 2 cars and real work space, choose 6m x 7.5m at minimum.
A 6m x 6m double garage is familiar because it fits neatly into plans and gives 36 square metres. It can hold 2 normal cars, but add a 600mm deep bench, shelving, mower, bikes and swinging doors and the usable aisle disappears. If the brief genuinely includes workshop space, 6m x 7.5m gives 9 extra square metres and 6m x 9m gives 18. Our straight recommendation is 6m x 9m when the block, budget and planning controls permit it.
For a single vehicle and wall storage, 3.6m x 6m is more forgiving than a bare 3m x 6m bay. For caravan or boat storage, measure the full hitched or trailered length, including drawbar, outboard, spare wheel and anything mounted on the roof. Add at least 600mm clear walking space where access is needed, and 1m to 1.2m beside a workbench where a person will operate tools.
The right size is not always the largest structure that can be squeezed onto the title. A shed that blocks winter sun, crowds drainage, removes the only garden access or requires a three-point turn every day is oversized for its site. Our garage and workshop page shows where custom bay and door layouts make more sense than a standard rectangle.
Plan from the inside out.
Vehicle envelope.
Measure length, body width, mirror-to-mirror width and height with roof racks fitted. Then add space to open at least the driver’s door, reach the boot and walk around the vehicle. A large four-wheel drive can be close to 5m long and more than 2m wide across mirrors. Designing from a nominal parking rectangle without the mirrors is how a double garage becomes a one-car garage with expensive storage beside it.
Workshop envelope.
Draw each bench at its real depth, commonly 600mm to 750mm. Mark a 1m operating zone in front, then plot machines at their full infeed and outfeed length. A 2m timber board needs clear travel, not merely a machine footprint. If welding or grinding is planned, separate sparks from vehicles, fuel and stored chemicals and allow an extraction route.
Storage envelope.
Shelving is normally 400mm to 600mm deep. Bicycles, kayaks and garden tools project further than their wall hooks. Plan high storage around door tracks and bracing rather than over them. If a mezzanine is being considered, its columns, stair, balustrade, loads and head clearances belong in the original engineering and permit, not as a later timber platform.
The clear opening is the number that matters.
A door described as 2.4m x 2.1m does not necessarily provide that exact clear passage after guides, stops and the rolled curtain are fitted. Ask the supplier for clear drive-through width and height. For a modern four-wheel drive, roof racks or a trade van, an opening around 2.7m to 3m wide and 2.4m high is usually easier to use if the design permits it.
One wide double door gives a flexible opening, while 2 single doors leave a useful wall pier and can reduce the amount of open frontage in bad weather. The trade-off is manoeuvring accuracy. On a narrow Casey lot, the driveway centreline may dictate the door position more strongly than the internal layout.
Keep a straight apron of roughly 5.5m to 6m in front where possible. For a 90-degree approach, draw or physically test the swept path of the longest vehicle. Check gutters, eaves, fence posts, retaining walls and the house corner. A roller door motor also needs headroom, and a sectional door can occupy ceiling space wanted for a hoist.
Do not choose height from the wall sheet alone.
Overall height includes wall height, roof pitch and ridge. Door clearance is lower than wall height, and a hoist needs clear internal height below rafters, bracing, lights and the open door. Give the designer the hoist manufacturer’s minimum slab, anchor and overhead requirements. For caravan storage, measure roof-mounted air conditioning and allow for driveway slope as the vehicle crosses the threshold.
In Victoria, the familiar permit exemption for a freestanding non-masonry shed applies only when every condition is met. Floor area must not exceed 10 square metres, overall height must not exceed 3m, or 2.4m when within 1m of a boundary, and siting conditions also apply. A 3m x 3m garden shed might qualify. A garage or workshop normally exceeds 10 square metres and needs a building permit.
Exemption from a building permit does not automatically clear a planning overlay, restrictive covenant, easement or authority asset. A structure near a Casey drain can need separate consent even if it is small. Start with the Casey shed permit guide and the City of Casey service page, then have the title and property controls checked against the final footprint.
Price the size you need and one size larger.
Moving from 6m x 6m to 6m x 9m adds 18 square metres. Depending on slab, earthworks, portal design, cladding and openings, a realistic full-build difference can be around $8,000 to $16,000. That is meaningful money, but permit, mobilisation and some design costs have already been paid. A later 3m extension needs new engineering, excavation, drainage changes, cladding removal and another disruptive build, so it rarely costs only the original per-metre difference.
Ask for both options on the same specification. Keep the same Colorbond profile, steel source, slab design basis, roller doors, gutters, insulation and electrical allowances. If the larger quote uses a cheaper door or removes insulation, it does not reveal the true size premium. Review complete project ranges on our 2026 shed pricing page.
The best time to test a footprint is before design fees are committed. Mark corners with stakes, run string for wall lines and park the actual vehicles inside for a weekend. Do it once after heavy rain as well, because the dry-season location may be the winter drainage path. Open every car door, carry the mower through, and walk the proposed route from house to yard after dark.
Shed sizing questions answered.
Measure the use, block and approach together.
We can mark out the footprint, check access and likely approval constraints, then price 2 sizes on the same specification.