Investor guide · Perth WA

Two rents from one block.

A single tenancy caps your gross yield at one rent. A dual-income property collects two. Add a granny flat behind the home, or build dual-key, and the numbers shift in your favour.

Last updated 14 June 2026. Figures are illustrative, general information only, not advice.

A dual-income property collects two rents from one block. The Property Plug builds dual income two ways: a granny flat behind the main home, or a dual-key design split into two self-contained dwellings under one title. Both lift gross yield past a single-tenancy build, and a granny flat is a separate depreciable asset of its own.

Two routes to a second rent

Indicative comparison. Suitability depends on block size, budget and local planning [TBC].
RouteWhat it isBest forDepreciation
Granny flatSeparate self-contained dwelling in the backyardLarger blocks, flexible use, future-proofingIts own fresh schedule
Dual-key homeOne building split into two private dwellings, one titleSmaller blocks, lower cost than two structuresSingle new-build schedule
01 Worked example

Main home plus granny flat, in Baldivis.

Horizon plus Haven granny flat, Baldivis. Build all-in is home plus siteworks, land separate. Rents are indicative assumptions.
Main home build all-in$335,528
Granny flat build all-in$238,268
Combined build (land separate)$573,796
Combined indicative rent$620 + $430 = $1050/week ($54,600/year)
Combined gross yield on build9.5% (vs 9.6% for the home alone)

Yield against build cost only. Add land for true net yield. Rents are indicative assumptions, not guarantees. Illustrative and general information only.

How to make the dual-income numbers work

  1. Pick a block that fits two dwellings. A granny flat needs backyard space and street or side access. A dual-key design fits a tighter lot because it is one structure.
  2. Price both builds for your suburb. Use the real siteworks figure, not a teaser. We publish it for 102 Perth suburbs.
  3. Model two rents, not one. Combine the achievable rents and divide by the combined build cost plus land for your true gross and net yield.
  4. Layer depreciation on both. A new main home and a new granny flat each carry their own depreciation schedule, improving after-tax cashflow.
  5. Finish turnkey. A turnkey contract means both dwellings let the day they hand over.

See the dual-key homes guide for the one-building route, and the rental yield guide to model the single-tenancy baseline.

This is general information only and does not take into account your objectives, financial situation or needs. It is not credit assistance or a credit quote. Consider whether it is right for you and seek advice. Finance is arranged through Central Lending Solutions, the licensed credit partner The Property Plug works with (Australian Credit Licence or credit representative number [TBC]).

02 Granny flats that pay

Eight granny flat designs, real from-prices, the builder matched to each on access.

All granny flats →
FAQDual-income questions
What is a dual-income property?

A dual-income property collects two separate rents from one block. The two routes are adding a granny flat behind the main home, or building a dual-key design split into two self-contained dwellings under one title. Both lift gross yield versus a single-tenancy home.

How much more does a dual-income property yield?

Adding a second rent lifts gross yield materially. As an indicative example, a Horizon plus the Haven granny flat in Baldivis builds for about $573,796 combined and at indicative rents of $620 and $430 per week returns roughly 9.5% gross, versus about 9.6% for the home alone. Illustrative, not a forecast.

Granny flat or dual-key, which is better?

A granny flat is a separate self-contained dwelling in the backyard, flexible and its own depreciable asset. A dual-key home is one building split into two private dwellings, cheaper than two structures and simpler to manage. Your block size, budget and rental market decide which suits.

Can I rent both dwellings in Perth?

In WA a self-contained ancillary dwelling, a granny flat, can generally be rented separately to the main home, subject to local planning and a maximum rentable floor area [TBC, confirm current WA ancillary-dwelling rules]. Dual-key dwellings are let independently under the one title.

How long does a granny flat take to build?

Allow 8 months for a granny flat from build start, subject to approvals and the builder's program. We are paid by the builder, never by you.

Your next step

Run the two-rent numbers

One short request. We price the main home and the granny flat for your suburb and model the combined yield with you. Free to you, no obligation.

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