Right, so you’re staring at your backyard thinking it’s big enough for another house. Maybe you’ve done the math on property prices lately (who hasn’t?) and reckon there’s decent money to be made.
Or perhaps you’ve got kids who’ll never afford their own place unless you help them out.
Before you get too excited though, let me tell you – backyard subdivision isn’t the goldmine that some property spruikers make it out to be. I’ve seen plenty of Perth homeowners dive in headfirst only to discover they’re in way over their heads.
But. It can work brilliantly when done right.
The Reality Check Nobody Talks About
Here’s what the property investment seminars don’t mention: roughly 40% of subdivision applications in Perth get rejected on the first go. And that’s just the ones that make it to council – plenty more die before they’re even lodged because the numbers don’t stack up.
The thing is, every block’s different. Your mate in Cannington might’ve made a killing subdividing his 800sqm block, but that doesn’t mean your 900sqm block in Wembley will work the same way. Different councils, different rules, different problems.
Size Isn’t Everything Most people think bigger blocks automatically mean easier subdivision. Not necessarily true. I recently looked at a massive 1,200sqm block in Bayswater that couldn’t be subdivided because of sewer line locations. Meanwhile, a clever 680sqm block in Mount Lawley worked perfectly because everything lined up just right.
The magic numbers vary by council, but generally you’re looking at:
- 600-700sqm minimum in most inner areas
- 800-900sqm in middle ring suburbs
- 1,000sqm+ in outer areas
But (and this is important) those are just starting points. Actual feasibility depends on shape, slope, existing services, and about twenty other factors.
Council Roulette: Not All Areas Are Equal
Some Perth councils love subdivision applications. Others… well, let’s just say they’re less enthusiastic. And it’s not always predictable.
The Easy Ones Councils like Wanneroo and Swan tend to be pretty straightforward. They’ve got clear guidelines, reasonable timeframes, and don’t seem to enjoy making life difficult just for the sake of it.
The Tricky Ones Heritage areas are obviously harder – think parts of Subiaco, Mount Lawley, and Cottesloe. But some councils that should be straightforward can be surprisingly difficult. I won’t name names, but let’s just say some inner eastern councils seem to think every subdivision application is a personal attack on their character.
The Wildcards Then you’ve got councils that vary massively depending on which officer gets your application. Same rules, completely different interpretations. It’s frustrating, but that’s just how it works.
The Money Talk (Because That’s Why You’re Here)
Let’s be honest about costs. A straightforward subdivision will run you somewhere between $25,000-$40,000 by the time you factor in everything:
- Town planner fees: $3,000-$8,000
- Surveying: $2,500-$4,000
- Council application fees: $2,000-$5,000
- Utility connections: $15,000-$25,000 (this is where it gets expensive)
- Legal costs: $1,500-$3,000
And that’s assuming everything goes smoothly. Which it usually doesn’t.
The Hidden Costs Stormwater drainage upgrades can add $10,000+ if your block doesn’t drain properly. Tree removal permits might cost $500 per tree (and good luck getting approval to remove anything decent-sized). Retaining walls for sloped blocks? That’s another $15,000-$30,000.
But here’s the thing – a successful subdivision in most Perth suburbs adds $150,000-$300,000 in total property value. So even with costs blowing out, the numbers often still work.
Water, Power, and Other Headaches
This is where subdivision gets properly complicated. Your existing house shares services with the new lot, which means everything needs to be separated and upgraded.
Water Meters Every lot needs its own water connection. Sounds simple, right? Except Water Corporation wants new connections sized for potential future development, fire service requirements, and various other complications. What starts as a $3,000 connection can easily become $8,000+ once they start talking about upgrading mains.
Electricity Similar story with Western Power. They’re generally pretty good to deal with, but if your area has old infrastructure, they might use your subdivision as an excuse to upgrade the whole street. Guess who pays?
Sewerage This one’s often the deal-breaker. If your existing sewer connection is too shallow, too small, or in the wrong place, you’re looking at major works. I’ve seen sewer upgrades cost $20,000+ because they had to run new pipes under existing buildings.
The Design Puzzle
Getting two houses to fit nicely on a block that was designed for one requires some creative thinking. It’s not just about cramming buildings wherever they’ll fit.
Orientation Matters Perth’s climate means orientation is crucial. You want living areas facing north for winter warmth, but not getting hammered by afternoon sun in summer. Sounds obvious, but you’d be surprised how many subdivisions ignore this completely.
Privacy Issues Nobody wants neighbours staring into their bedroom windows. Good subdivision design creates natural privacy through clever positioning, landscaping, and window placement. Bad design leads to years of awkward encounters and eventual fence wars.
Car Parking Most councils want two car spaces per dwelling, which eats up surprising amounts of space on smaller blocks. Creative driveway design can help, but there are limits to how clever you can get.
Common Mistakes That Cost Money
Assuming Existing Services Are Adequate Just because your house has power and water doesn’t mean there’s enough capacity for two houses. Get services investigated early – preferably before you spend money on design work.
Ignoring Slope Issues A gently sloping block might look fine, but subdivision often requires flat building pads. That “gentle” slope could need $20,000 worth of earthworks and retaining walls.
Underestimating Tree Requirements Perth councils are getting stricter about tree retention. That big jarrah in your backyard might be protected, which could completely change your subdivision layout. Or make it impossible altogether.
Not Checking Neighbour Easements Your property might have easements for neighbour access, services, or stormwater. These can seriously limit where you can build, but lots of people only discover them after they’ve committed to the subdivision process.
Timeline Reality Check
If someone tells you subdivision is quick, they’re either lying or they’ve never actually done one. Here’s what actually happens:
- Initial investigations and design: 6-12 weeks
- Council application lodgement: 2-4 weeks (just to prepare everything)
- Council assessment: 12-20 weeks (officially it’s shorter, but there are always questions)
- Conditions clearance: 8-16 weeks
- Title creation: 4-8 weeks
So you’re looking at roughly 12-18 months from start to finish. And that’s if everything goes smoothly, which it usually doesn’t.
When It Makes Sense (And When It Doesn’t)
Good Candidates:
- Blocks over 700sqm in established suburbs
- Properties with good street frontage
- Areas with strong rental or sales demand
- Owners planning to hold long-term
Think Twice If:
- Your block’s an awkward shape
- There are significant slope issues
- Heritage overlays apply
- You need the money quickly
Don’t Even Consider It If:
- Your block’s under 600sqm
- Major infrastructure upgrades are needed in your street
- Council’s currently reviewing planning policies in your area
The Professional Reality
Look, you can technically handle subdivision applications yourself. Councils have to accept applications from property owners. But honestly? It’s like doing your own brain surgery because you’ve watched some YouTube videos.
Town planners who specialise in subdivision know which councils are reasonable, which officers are helpful, and how to present applications that actually get approved. They’ve made all the mistakes on other people’s projects.
More importantly, they can spot problems early. It’s much cheaper to discover your subdivision won’t work during the feasibility stage than after you’ve spent $15,000 on applications and surveys.
Final Thoughts
Backyard subdivision can be brilliant if you do it right. But “right” means understanding all the complexities upfront, budgeting properly, and having realistic expectations about timeframes.
The Perth property market makes subdivision attractive, but don’t let dollar signs blind you to the risks. Get proper advice early, budget for cost blowouts, and remember that some blocks just aren’t suitable no matter how much you want them to be.
Done well though? It’s still one of the better ways to create wealth from property in Perth. Just go in with your eyes open.