How I Screen Every Suburb in Australia Before Buying a Single House

I built my first property screening model in a spreadsheet at 2am on a Tuesday. It was ugly. Three tabs, a dozen columns, manual data entry from Domain and the ABS. But it told me something I didn't know before: the suburbs I thought were good investments were actually mediocre, and the suburbs I'd never heard of were gold mines.

That was over 350 transactions ago.

Today, the model runs daily. It scans every suburb across the country against four core metrics. Not feelings. Not 'local knowledge' from a real estate agent trying to sell you something. Just numbers — cold, boring, extraordinarily reliable numbers.

In property investment, there are really only three things you need to get right: pick the right area, pick the right land, and pick the right house. Most people stuff up step one because they let emotion drive the decision. They buy near their parents' place, or in the suburb their colleague recommended, or wherever the latest property podcast said was 'about to boom.'

Let me show you how to do it with data instead.

Step 1: The four numbers that matter

Every suburb I look at gets filtered through four metrics. If it fails any one of them, it's out. No exceptions, no 'but it feels right.'

Number 1: Affordability ratio (target: 7-8x)

Take the suburb's median house price. Divide it by the median household income. If the result is between 7 and 8, you're in the sweet spot 1.

Below 7 means the suburb is genuinely cheap — which usually means there's a reason it's cheap (poor infrastructure, declining population, high crime). Above 8 means the suburb is already expensive relative to local incomes, which compresses future growth. When houses cost more than 8 times what local families earn, buyer demand plateaus because fewer people can actually afford to enter the market.

The 7-8 range means houses are still within reach for working families — which sustains demand — but tight enough that supply-demand dynamics push prices upward over time.

Number 2: Population-to-dwelling ratio (target: above 3)

This one's simple but powerful. How many people live in the suburb divided by how many dwellings exist. If you're above 3, it means each dwelling houses more than three people on average — a sign that housing stock is undersupplied relative to population 2.

Suburbs where families are squeezing into shared houses, where young couples are living with in-laws, where rental listings get 30-50 applications within a week — those are the suburbs above 3. That's where rental demand is structural, not cyclical.

Number 3: Mortgage stress ratio (target: below 30%)

Monthly mortgage repayment as a percentage of median household income. If it's above 30%, residents are under financial pressure. That might seem like a good thing for landlords (more renters), but it actually signals a ceiling on price growth 3.

When mortgage stress is high, fewer owner-occupiers can enter the market, which suppresses demand. And in severe cases, it leads to forced sales — which drags down comparable values across the suburb. You want suburbs where residents can comfortably service their mortgages, because that means the market can absorb further price increases without breaking.

Number 4: Vacancy rate (target: below 2%)

The first three metrics measure buy-side fundamentals. This one measures rent-side fundamentals. A vacancy rate below 2% means there are more tenants looking for properties than there are properties available 4. At that level, you have genuine pricing power as a landlord. You can achieve above-market rents. You can be selective about tenant quality.

Above 3% and the power shifts to tenants. Above 5% and you're in trouble — properties sit empty, you start making concessions, and your cash flow projections fall apart.

I run these four numbers on every suburb in Victoria every week. The output is a shortlist of maybe 15-20 suburbs that pass all four filters. Those are the only suburbs we buy in.

Step 2: The land — two things to look for, one thing to avoid

Once you've identified the right suburb, you need the right block. This is where most buyer's agents stop at 'location, location, location' and hope for the best. I want to be more specific than that.

Look for: Development potential

A block with subdivision or development potential will outperform a similar block without it by 30-50% over a ten-year hold period 5. The reason is straightforward: you're buying optionality. Even if you never develop, the next buyer might — and they'll pay a premium for the possibility.

What makes a block developable? Size matters — you generally need at least 500 square metres to fit two dwellings. Width matters — you want room for a second driveway. Slope matters — flat is better, gentle slope is acceptable, steep slope is expensive. Shape matters — rectangular beats irregular every time.

And then there's zoning. If the block sits in a Residential Growth Zone (RGZ) or Activity Zone, the council has essentially pre-approved higher density. That's a green light for future value.

One of our strongest case studies came from recognising development potential others missed. A 730-square-metre block in Boronia listed at $660,000. Previous buyers had been scared off by what they thought was a flood zone designation. Our team investigated and found it was incorrectly mapped — the property sat above the flood line. We bought it off-market, and four weeks after settlement, the bank valued it at $890,000. A $230,000 paper gain, largely because the development potential of a 730-square-metre cleared block in that location was enormous 6.

Look for: Location bonuses

Proximity to train stations adds value. Proximity to shopping centres adds value. Proximity to arterial roads adds value. These aren't opinions — they're measurable in comparable sales data.

But here's the counterintuitive bit: proximity to the CBD is actually a negative indicator for capital growth at our price point. The closer to the city, the more expensive the house. The more expensive the house, the lower the percentage growth. A $1.5 million house in a blue-chip suburb might grow 4% a year. A $650,000 house in a well-selected outer suburb can grow 8-10% 7. That's the affordability ratio at work again.

Avoid: Encumbrances and hazards

Easements running through the property — especially sewer or drainage easements — destroy development potential. The council can dig up your backyard anytime. Flood zones, bushfire overlays, high-voltage transmission lines, aircraft noise corridors — these all suppress both value and growth.

We physically inspect every property before recommending it. Our field team — Steven and Edward — checks ground levels, examines drainage, measures setbacks, and reviews council overlays on-site. They've saved clients from buying properties with hidden easements, undisclosed retaining wall obligations, and incorrectly represented land sizes more times than I can count 8.

Step 3: The house — what to buy and what to fix

The house itself is actually the least important part of the equation. I know that sounds strange coming from someone who buys houses for a living, but hear me out.

We follow an 80% rule: at least 80% of the purchase price should represent land value. Buildings depreciate. Land appreciates. Every dollar you pay for a fancy kitchen or a swimming pool is a dollar that's losing value from day one 9.

This is why we actively seek out what the market calls 'ugly' houses — properties with cosmetic issues that scare off emotional buyers but don't affect structural integrity. Outdated kitchens, tired carpets, peeling paint, overgrown gardens. These are problems that cost $10,000-$15,000 to fix but add $30,000-$50,000 in value and $200-$300 per week in rental income 10.

Our renovation team handles everything in-house. A typical cosmetic reno takes two to three weeks and includes fresh paint throughout, new flooring (usually hybrid timber or vinyl plank), updated kitchen hardware and benchtops, modernised bathroom fixtures, and landscaping front and rear.

The numbers from a recent Hampton Park purchase tell the story. Bought at $590,000 — a house with white ant damage, a leaking roof, and foundation cracks. Most buyers walked away at the inspection. We saw a 600+ square metre block of land in a suburb passing all four screening metrics, attached to a house that needed $40,000-$50,000 in repairs.

Post-renovation, CBA gave it a desktop valuation of $670,000. Rent came in at $850 per week. That's a gross yield of 7.5% on the purchase price, or 6.8% on the total cost including renos. In a suburb where the average yield is 3.5-4%, that's not a marginal improvement — it's a completely different investment proposition 11.

Another example: Narre Warren. Purchase price around $738,000 for a 600+ square metre block. No major renovation needed — the house was liveable. Within six months, the bank valued it at $772,000. A $34,000 gain from pure market movement, representing a 4.6% capital appreciation in half a year. The suburb was growing at roughly $5,000 per month during that period 12.

The difference between these outcomes and the average investor experience isn't luck. It's the screening process. Both properties sat in suburbs that passed all four filters. Both had land-to-value ratios above 80%. Both were purchased below bank valuation — the Hampton Park deal was $80,000 below, the Narre Warren deal was $34,000 below.

Why most 'hot tips' are actually cold leads

I get asked about specific suburbs constantly. 'What about Point Cook?' 'Is Tarneit any good?' 'My uncle made a killing in Werribee.'

Maybe. But I don't invest based on anecdotes. When someone tells me a suburb is great, my first question is always: what's the affordability ratio? What's the vacancy rate? What's the population-to-dwelling ratio?

Usually, they have no idea. They bought there because they heard it was good, or because they could afford it, or because someone they trust recommended it.

The suburbs that consistently pass my four-filter screen are not the ones getting breathless coverage in the property press. They're working-class suburbs in Melbourne's southeast and east — places like Cranbourne, Hampton Park, Doveton, Frankston, Boronia, Kilsyth. Not glamorous. Not 'aspirational.' But the numbers are exceptional 13.

These suburbs share common characteristics: strong population growth driven by family formation, limited new land supply (no greenfield releases competing with existing stock), established infrastructure (schools, shops, transport), and median prices in the $550,000-$750,000 range where the bulk of buyer demand sits.

The real potential isn't in the suburbs everyone's talking about. It's in the suburbs nobody's talking about — because those are the ones where the data says the fundamentals are strongest, and where you can still buy below replacement cost.

I've been running this screening model for years now, across more than 350 completed transactions. The properties that performed best — the ones delivering 8-10% annual capital growth plus 5-7% rental yields — all came from the same short list. The model works because property markets are fundamentally driven by supply and demand, and supply and demand are measurable.

FAQ

Where do I get the data to run these screens myself? The ABS publishes population and household income data by Statistical Area (SA2). The Victorian government publishes vacancy rates. CoreLogic and Domain publish median prices. It's all publicly available — the skill is in knowing how to combine them and what thresholds to use. We run our own proprietary model that updates daily, but the raw inputs are free.

What about regional areas outside Melbourne? Our framework applies nationally, though the specific thresholds shift. In regional Victoria — Geelong, Ballarat, Bendigo — affordability ratios of 5-6x are more appropriate, and you're trading capital growth for higher yields. We buy in these areas for clients who prioritise cash flow over appreciation, typically in the $350,000-$500,000 range.

How important is the house itself vs the land? The house is the least important variable. We follow an 80% land rule — at least 80% of the purchase price should represent land value. Buildings depreciate from day one. A rundown house on a premium block will outperform a premium house on a poor block every single time over a 10-year hold.