Pergolas in Pakenham & Cardinia Shire.

• Cypress + treated-pine slat pergola: the classic. Cypress posts (Murray River pine), treated pine slatted top, optional vine wire for climbing plants. Weathers silver-grey beautifully. ~$5,000–$7,500 for a 4 x 4m.
• Steel post + timber slat pergola: the modern Cardinia Lakes default. 100x100 SHS galv steel posts, merbau or spotted-gum slats overhead. Slimmer post profile, longer span available. ~$6,500–$9,000 for a 4 x 4m.
• Steel post + steel batten: contemporary minimal. Galv or powder-coated steel posts with steel battens at 100mm centres. Painted match-to-house or natural galv. ~$7,000–$10,000 for a 4 x 4m.
• Vine-wire-only pergola: stainless cable wires running between posts for a grape, wisteria or climbing rose to grow across. Lowest cost, takes 2–3 seasons to fill in. ~$4,000–$6,000 for a 4 x 4m.
• Polycarbonate-roofed pergola: sheltered but light. Bronze or opal polycarbonate over a steel or timber frame. Cheaper than Colorbond, lets light through. ~$6,500–$9,500 for a 4 x 4m. Technically a patio under Cardinia’s definition.

Material choices.

• Cypress posts: 30+ year ground-contact-rated, termite-resistant, weathers silver-grey untreated, paintable. The traditional Cardinia choice. ~$95–$140/m of post.
• Treated pine posts (H4 ground-contact): cheaper, paintable, 20–25 year life if maintained. ~$60–$95/m.
• Hot-dip-galv steel posts (100x100 SHS): structural longevity, slim profile, suits modern facades. ~$110–$160/m.
• Powder-coated steel posts: as above, painted match-to-house. ~$140–$190/m.
• Merbau slats overhead: warm red-brown, oiled finish, lasts 25+ years. Premium look.
• Spotted-gum or blackbutt slats: Australian hardwood, lighter tone. Premium.
• Treated pine slats: paintable, cheapest, needs paint touch-up every 5–7 years.

Sizing and footings.

A typical Cardinia Lakes / Officer Estate rear-yard pergola is 4 x 4m or 4 x 5m, just covering the existing alfresco slab. We use 4 posts on a 4 x 4m, 6 posts on a 4 x 5m or larger. Footings are 900mm concrete pads on Class M reactive clay (same as for carports — the soil doesn’t care that the structure is lighter). Posts bolt into stirrups cast into the footing tops, so timber posts never sit in contact with the ground.

Permit pathway for pergolas.

• Open-frame, under 20m², under 3m height, behind building line, no overlay: generally exempt from building permit under the Building Regulations 2018 schedule.
• Over 20m² or over 3m: building permit ($450–$900 fee + private surveyor $1,200–$2,000).
• Heritage Overlay (parts of Officer, Beaconsfield Upper, Pakenham CBD): planning permit + heritage advisor referral. Steel-post modern pergolas usually refused; cypress + traditional batten approved.
• Forward of building line: planning permit usually required.

Most popular Cardinia growth-corridor build.

The default 2026 Cardinia Lakes / Officer Estate pergola: 4 x 4m open-frame, 4 steel posts in Monument powder-coat, merbau slats overhead at 100mm centres with 100mm gaps, ceiling fan rough-in, integrated LED downlights, no roof. Around $7,500–$9,500 installed. Works over a poured-slab alfresco, permit-exempt at 16m², suits dark-Colorbond facades, and gives you dappled shade plus full breeze.