Can You Build a Pool on a Sloping Block in Sydney?
Completed concrete pool build by Cronulla Pools, Sydney pool builders.
Think your yard's too steep for a pool? You're definitely not alone. It's one of the most common things people say to me on the phone, usually right before they apologise for wasting my time.
You're not wasting my time. In most cases, yes, you can build a pool on a sloping block. It just changes how we build it. The pool might sit partly out of the ground, you might need retaining walls, and there's more engineering and planning involved, but that part is on us.
Sydney is basically one big hill with water at the bottom, so we build on slopes all the time, from the Shire to the Northern Beaches to the Illawarra escarpment.
How do you build a pool on a sloping block?
There are three main ways, and lots of pools use a combination.
Fully in-ground with retaining. We cut into the slope, build retaining walls on the high side and set the pool into the ground. This works best on gentle slopes.
Partly out of ground (semi in-ground). The pool is dug in on the high side and sits up out of the ground on the low side. The exposed concrete wall gets finished with cladding, render or tiles. This is the most common approach on a decent slope and honestly my favourite, because the view from the pool on the low side is usually the best bit of the whole yard.
Fully out of ground. On really steep sites, the pool can be built entirely above the ground and engineered to stand on its own. We recently built one where I could stand at the base of the wall and it was well over my head.
A concrete pool is the one that makes all of this possible, because it's built in place to fit your site. A fibreglass shell comes in set shapes and depths and needs to be supported properly all the way around.
What a slope does to the design
A slope isn't just a problem to solve, it opens up some really cool options:
Pool windows in the exposed wall on the low side
Wet edges and overflow edges looking out to the view
Raised walls you can perch on, which double as seating
Decks and terraces at different levels
A pool that runs straight off the back deck, if the levels and approvals allow it
Where the levels land matters a lot. How you step from the house to the pool, whether there's room for sun lounges, where the fence goes. Our landscape designer Luke works this out in 3D so you can see how the levels feel before anything gets dug.
Approvals on a sloping block: CDC or DA?
This is where slopes can get a bit technical. In NSW, a pool can be approved as complying development (a CDC, the fast-track path) if it meets a set of standards. One of those standards limits how far the pool can sit above the existing ground. According to the NSW Government's guide to complying development, pool coping can be a maximum of 1.4m above existing ground level, and only 0.3m wide if it's more than 0.6m above ground.
If your pool needs to sit higher than that, or the design doesn't fit the other standards, it will usually need a development application (DA) through council instead. That takes longer, but it's very doable. We work it out early so you know which path you're on before you fall in love with a design.
Does a sloping block make a pool more expensive?
Usually, yes, and I'd rather tell you now than surprise you later. The things that move the price on a slope are:
Retaining walls and extra engineering
Excavation, especially if access is tight or we hit rock
Getting machinery and materials in. On steep sites we use conveyor belts and chutes, and sometimes a crane
Finishing the exposed walls with cladding or tiles
Extra steel and concrete for an out-of-ground structure
Most concrete pools we build in Sydney land between $100,000 and $150,000, and slopes tend to push towards the upper end or beyond. Every site is quoted individually, because two slopes that look the same from the street can be very different once we're standing in the yard.
What to have ready before you call
A recent survey with levels (this is gold on a sloping block)
Your 10.7 planning certificate from council
House plans if you have them
Photos of the yard from the house and from the bottom of the slope
A rough idea of budget and when you'd like to be swimming
If you don't have a survey or 10.7 yet, don't worry, we can organise both.
Wrap up
So if you've been staring at a steep, rocky yard from the kitchen window thinking there's nothing you can do with it, send me a few photos of your slopey space and let me be the judge, because more often than not that awkward slope ends up being the best thing about the finished pool.
