Building on a Bardon Hillside — The Anderson Build

The block in Bardon had a 4m drop across its 30m depth. Steep. The kind of slope that makes pool builders sigh and quote 30% extra.

The owners, the Andersons, had been getting quotes for two years. They'd lived with the idea, given it up twice, and circled back to us through a friend who'd built with Wahoo three years earlier. They were honest: this was their last attempt before they accepted the yard couldn't have a pool.

Build started in March. Finished in late May. 11 weeks total. Resort I (7×4m), modified for the slope, with retaining walls and a split-level deck. Final invoice: $79,400 including site-specific engineering.

The challenge

Bardon hillsides are spectacular but unforgiving. The Andersons' block dropped sharply from the rear of the house down toward the gully behind. The flat section near the house was tiny — maybe 4m deep — then it fell away.

Two design options:

Option A: push the pool into the slope (excavate down). Get retaining walls on the high side, pool sits below ground level on the up-hill side, emerges at deck level on the down-hill side. Expensive engineering, lots of dirt to remove.

Option B: raise the pool (build up). Build a substantial retaining wall on the down-hill side, fill behind it, put the pool on top. Less excavation but more concrete and a bigger structural challenge.

We modelled both. Option A worked out about $8,000 cheaper and visually integrated the pool into the landscape rather than perching it above. We went with A.

The engineering

Our standard structural engineer came out specifically for this site. He spec'd 250mm shell walls (instead of our standard 200mm) and 350mm thick reinforced concrete on the high-side retaining structure.

The retaining wall on the high side was actually integrated with the pool wall structurally — they share a footing and reinforcement. This is the kind of design that separates a pool that lasts from one that develops issues in 5-10 years.

Engineer inspection at steel stage passed first time. We waited an extra day for him to do a second look at the retaining tie-in. Worth the day.

The build

Excavation took longer than usual — 5 days instead of 3. The slope meant the excavator had to work in stages, and we had three truck deliveries to remove the spoil rather than two.

Steel and shotcrete went smoothly. The split-level deck around the pool was the most labour-intensive part — timber framing, multiple level changes, frameless glass at varying heights.

One detail we're proud of: the pool's high-side coping sits flush with the existing back deck. From the house, the pool looks like it's at ground level. Walk around to the side and you realise the pool's interior is 2m below the deck level on the down-hill side. The illusion of flatness is what makes the build look intentional.

The variations

Two changes during the build, both for legitimate reasons.

Variation 1: additional drainage from the retaining wall. Once the wall was up, we realised the natural water flow on the slope would push behind the wall over time. We installed a sub-soil drain at the base, $1,800. The Andersons signed off without hesitation.

Variation 2: upgrading to bluestone coping after the initial travertine sample looked too bright against the bushland backdrop. They paid the difference, $2,400. The bluestone looks fantastic.

Total variations: $4,200. Final invoice $79,400.

The result

The pool reads as part of the landscape rather than imposed on it. From the deck, you see water level with the horizon, native eucalyptus framing the view down into the gully, and a calm rectangular pool. From the gully looking back, you see the pool's down-hill structural face — clean concrete and bluestone, almost architectural.

Mr Anderson sent us a photo three months after handover. The pool is half in shadow, half in afternoon sun. The water reflects the gum trees. It looks like it's been there forever.

What this taught us

Sloping sites need experienced builders. Not because the work is impossibly hard, but because the design decisions are interconnected — retaining strategy, drainage, structural tie-ins, visual integration with the slope. A builder who's done a dozen of these will see options a generalist won't.

If you've got a sloping block in Bardon, The Gap, Kenmore, Indooroopilly or anywhere similar, don't accept 'too hard'. Talk to us about your site. We've done plenty of these.

— Cathy

Family name changed for client privacy. Project details accurate.