What Vacancy Rate actually measures

Vacancy Rate is the percentage of rental properties in a suburb that are available for lease but unoccupied on a given date. It’s usually measured monthly by data providers like SQM Research or CoreLogic.

If a suburb has 500 rental properties and 10 are sitting empty, the vacancy rate is 2.0%.

The bands that matter

For Australian capital city suburbs:

  • Under 1.0% — severe undersupply. Extreme rent growth pressure. Tenants compete, queue, and offer above asking. Often precedes 15–25% annual rent rises.
  • 1.0–2.0% — tight. Landlords have strong pricing power. Typical yield-favourable market.
  • 2.0–3.0% — balanced. Healthy functioning market. Neither side has strong leverage.
  • 3.0–4.5% — soft. Tenants have options, landlords compete on price, rents flat or falling.
  • Above 4.5% — oversupplied. Rent concessions common. Landlords facing genuine vacancy risk.

Perth in early 2026 has been sitting at 0.8–1.3% across most suburbs — extremely tight, and driving the rental yield story that’s attracting east coast investors.

Why vacancy leads rent growth

Vacancy doesn’t cause rent growth directly — it’s a signal that undersupply exists. But the relationship is strong enough that vacancy rate is often the best predictor of future rent increases.

The typical sequence:

  1. Population growth or demand shift pushes tenants into a suburb
  2. Vacancy drops as existing stock absorbs demand
  3. Rents begin rising as landlords test the market
  4. Higher rents attract new investors, eventually driving construction
  5. New supply absorbs tenants, vacancy normalises, rent growth moderates

If you can buy during step 2 (vacancy dropping, rents not yet rising), you catch the upswing. By step 4 everyone can see the story and prices have priced it in.

What vacancy can’t tell you

Vacancy is a present snapshot. It doesn’t tell you:

  • Why vacancy is tight (population influx vs stock withdrawal vs temporary)
  • How long it will stay tight (depends on approvals pipeline)
  • Tenant quality (a suburb can have 0.5% vacancy but high turnover and rent arrears)

Pair vacancy with SEIFA, household income trends, and new dwelling approvals to see the full picture.

Why Perth’s sub-1% vacancy is structural, not temporary

Perth’s vacancy crisis has specific drivers:

  • Strong interstate migration (14,800/yr net to WA)
  • Limited new construction through 2020–2023
  • Surging demand from mining sector workers
  • Investor activity removing stock from the rental pool

Unwinding any of these takes years, not months. Investors watching Perth are effectively betting that vacancy stays below 2% for several more years — which seems well-supported by current data.