How to build a pergola, the Aussie weekend backyard project
Pergolas are one of the most-built outdoor structures in Australian backyards. Here's how to build one yourself, plus the council rules to check first.
Tools and materials
Tools
- Post-hole digger or hired auger
- Mitre saw or circular saw
- Cordless drill / impact driver
- Spirit level (600mm and 1.2m)
- Tape measure
- String line
- Stepladder
Materials
- 4x posts (treated pine 90 x 90mm or hardwood 100 x 100mm)
- Beams (treated pine 190 x 45mm or similar)
- Rafters (treated pine 140 x 45mm or similar)
- Post brackets and saddles
- Galvanised bolts and structural screws
- Concrete (20kg bags or premix)
- Optional: roofing iron, polycarbonate, or shadecloth
A pergola transforms a backyard. Free-standing ones are the easiest outdoor structure to DIY in Australia, no major plumbing or electrical, manageable timber sizes, and a satisfying weekend project for any confident handyperson.
This is genuine DIY territory for free-standing pergolas under the state exemption thresholds. Attached pergolas, larger structures, and anything in a heritage or bushfire area need council approval and often a registered builder.
The 5-day build (across 2 to 3 weekends)
| Day | Task |
|---|---|
| Day 1 | Mark out, dig 4 post holes |
| Day 2 | Set posts in concrete, let cure 24 hours |
| Day 3 | Fit beams between posts |
| Day 4 | Fit rafters across beams |
| Day 5 | Optional roofing (shadecloth, polycarbonate, slats) |
A fit DIYer with a helper does this in two solid weekends. Allow extra days between concrete pours and the structural work.
Standard dimensions
A typical residential pergola is 3 to 4m wide x 4 to 6m long. Most Aussie councils class anything under 20 to 25 m² as exempt (free-standing). Post height 2.4m at the high side, sometimes lower if sloping to one side for water runoff.
Materials cost for a 3 x 4m treated pine pergola
| Item | Quantity | Cost (AUD) |
|---|---|---|
| 90 x 90mm treated pine posts (3.0m long) | 4 | $60 to $90 each |
| 190 x 45mm beams | 2 at 4m | $50 to $80 each |
| 140 x 45mm rafters | 6 at 4m | $30 to $50 each |
| Post saddles and brackets | 4 sets | $20 to $40 each |
| Galvanised bolts and screws | $80 to $120 | |
| Concrete (20kg bags) | 8 bags | $80 to $100 |
| Materials total | $700 to $1,200 |
Plus roofing if adding:
- Shadecloth (90% shade with eyelets, ~$25/m²): $250 to $400 for a 3x4m pergola
- Polycarbonate (per sheet, includes glazing bars): $400 to $900 for the same area
- Colorbond roofing (with battens, gutters): $800 to $1,500 for the same area
When this becomes a builder’s job
- Pergola larger than 25 m² floor area
- Attached to the dwelling
- Higher than 3m at any point
- In a bushfire-prone area (BAL rating 12+ usually triggers specific requirements)
- In a heritage conservation area
- Closer than 600mm to a boundary
- Roofed with structural Colorbond (some councils class this as a “verandah” not “pergola”)
- On uneven ground requiring engineered footings
For standard 3x4m or 4x4m free-standing pergolas in suburban backyards, this is real DIY work.
The hidden cost: removing it later
Pergolas can be a small headache at property sale time if they were built without approval and they should have been approved. Even a free-standing 4x4m structure can technically need council approval depending on your state and council. Building inspections at sale catch unapproved structures, and the next owner may demand retrospective approval or removal.
If you’re unsure, pay $200 for a pre-DA consultation with your council before starting. Cheap insurance.
Frequently asked questions
Do I need council approval for a pergola in Australia?
Often yes. Most states allow free-standing pergolas under exempt or complying development if under 25 m² area, under 3m height, set back appropriately from boundaries, and not in a heritage or bushfire overlay. Attached pergolas (fixed to the house) almost always need approval. Always check your local council before starting. See our [decking and pergola rules guide](/guides/carpentry/decking-and-pergola-rules-by-state/) for state-by-state detail.
How much does it cost to build a pergola?
$800 to $2,000 in materials for a basic 3 x 4m treated-pine pergola. $1,500 to $3,500 for hardwood or steel framing. Add $500 to $1,500 if you're adding roofing iron or polycarbonate. Professional build from a contractor: $4,000 to $12,000 for the same size.
Can I attach a pergola to my house?
Yes but it triggers more rules. Attached pergolas usually need council approval, structural engineering for the bolting connection to the dwelling, and waterproofing where it meets the existing roof. Most states classify attached pergolas under 'addition' rules, not 'pergola' rules. Free-standing pergolas (4 posts, no contact with the house) have looser rules.
What roofing for a pergola in Australia?
Three options. <strong>Open slats</strong>: timber rafters with gaps, lets sun through. <strong>Shadecloth</strong>: stretched fabric, 70 to 90% shade, cheap, lasts 5 to 10 years. <strong>Polycarbonate</strong>: rigid translucent panels, lets light through, weatherproof, lasts 15 to 20 years. <strong>Colorbond</strong>: opaque steel, full shade, looks structural, needs falls for water runoff.