Granny Flats Perth · Detached, attached & conversions
Granny Flats
Perth.
Granny flats Perth-wide — detached, attached and conversion ancillary dwellings by a WA-licensed builder. BC104702 active since 2023. R-Codes compliant, council-approved in our name, statutory home-warranty under the WA Home Building Act, twelve months direct aftercare on every job.
2023
Trading since — WA construction company
BC104702
WA Builder Licence — current
$7.5K–$300K+
Project range delivered to date
12mo
Direct aftercare on every job
What we build
Four paths to a
granny flat Perth-wide.
Granny flats Perth fall into four delivery types — detached, attached, conversion or investment-grade. Each suits a different block, brief and budget. We design for the lot’s R-Codes, your privacy needs and how the dwelling will be used.
01 · Detached
Standalone dwelling.
Separate building on the same block — full privacy, separate entrance, own utilities. Most popular path for parents, adult children or rental.
02 · Attached
Linked to main dwelling.
Attached to the main house with separate entrance and utilities. Lower cost than detached, easier services connection, suits narrow blocks.
03 · Conversion
Existing to dwelling.
Converting an existing structure — garage, studio, outbuilding — into a compliant ancillary dwelling. Lowest cost, most council complexity.
04 · Investment
Rental-ready spec.
Built to investment-property spec — durable finishes, separate metering, rent-ready handover. Designed for yield, not occasional use.
What we build
Four paths to a
granny flat Perth-wide.
Granny flats Perth fall into four delivery types — detached, attached, conversion or investment-grade. Each suits a different block, brief and budget. We design for the lot’s R-Codes, your privacy needs and how the dwelling will be used.
Granny flats Perth fall into four delivery types — detached, attached, conversion or investment-grade. Each suits a different block, brief and budget. We design for the lot’s R-Codes, your privacy needs and how the dwelling will be used.
01 · Detached
Standalone dwelling.
Separate building on the same block — full privacy, separate entrance, own utilities. Most popular path for parents, adult children or rental.
02 · Attached
Linked to main dwelling.
Attached to the main house with separate entrance and utilities. Lower cost than detached, easier services connection, suits narrow blocks.
03 · Conversion
Existing to dwelling.
Converting an existing structure — garage, studio, outbuilding — into a compliant ancillary dwelling. Lowest cost, most council complexity.
04 · Investment
Rental-ready spec.
Built to investment-property spec — durable finishes, separate metering, rent-ready handover. Designed for yield, not occasional use.
R-Codes & approvals
What WA R-Codes
actually allow
for granny flats
Perth.
The Residential Design Codes (R-Codes) govern every ancillary dwelling in Perth. Size, setback, parking, site coverage — all set by code, all assessable by council. The good news: WA reforms in recent years have made approvals more workable than they were a decade ago.
What’s typically allowed
Three rules that decide your build.
Council approval process
Lodged in our name, not yours.
Most ancillary dwellings need development approval, building permit, or both. The application sits in the licensed builder’s name — not the homeowner’s, not a kit-supplier’s.
Liability for compliance flows with the licence. We assess what’s needed at brief stage and lodge the application directly with your local council.
R-Codes & approvals
What WA R-Codes
actually allow
for granny flats
Perth.
The Residential Design Codes (R-Codes) govern every ancillary dwelling in Perth. Size, setback, parking, site coverage — all set by code, all assessable by council. The good news: WA reforms in recent years have made approvals more workable than they were a decade ago.
What’s typically allowed
Three rules that decide your build.
Council approval process
Lodged in our name, not yours.
Most ancillary dwellings need development approval, building permit, or both. The application sits in the licensed builder’s name — not the homeowner’s, not a kit-supplier’s.
Liability for compliance flows with the licence. We assess what’s needed at brief stage and lodge the application directly with your local council.
Why us
Why Perth
homeowners
brief us for granny
flats Perth.
Four practical reasons clients pick GPD over a kit-supplier. The unglamorous things that decide whether a granny flat lasts thirty years and rents reliably — or doesn’t.
01
A WA licensed builder.
BC104702 since 2023. Statutory home-warranty under the WA Home Building Act applies on residential builds over $20,000. Liability flows with the licence.
02
Builder, not a kit-shop.
Most “granny flat” suppliers are kit shops with installer crews. GPD is a builder running delivery in our name — defects and warranty sit with us, not a fly-by-night reseller.
03
Direct line to the builder.
Owner-operated. The builder reads every brief, signs every contract, runs every site meeting. No project-manager intermediary, no head-office bottleneck on decisions.
04
Twelve months aftercare.
Direct aftercare line for twelve months from handover, every job. Statutory warranty under the WA Home Building Act applies on top of that for the warranty period.
Adjacent residential work
Recent residential builds at scale.
A granny flat is essentially a self-contained residential build at compact scale. Below — two recent residential projects from the GPD register that demonstrate the quality and structural complexity we deliver. Reference contacts available on request.
Investment & timeline
What a Perth
granny flat actually
costs.
Three honest price bands based on real Perth granny-flat market economics in 2026. No “from $X” marketing fluff. Fixed-price contracts on signed scope.
Conversion
$80k–$140k
3–4 months · existing structure
Converting a garage, studio or outbuilding to a compliant ancillary dwelling. Lowest cost path. Full kitchen, bathroom, services, R-Codes compliance.
Standard
$140k–$220k
4–6 months · most popular
Standard new-build granny flat — 60–70m², 1–2 bed, attached or detached. Council-approved, R-Codes compliant. Most-quoted band Perth-wide.
Premium
$220k+
5–8 months · larger spec
Larger ancillary dwelling — up to 120m² where council permits, 2 bed, premium specification. Investment-grade or multi-generational use cases.
Investment & timeline
What a Perth
granny flat actually
costs.
Three honest price bands based on real Perth granny-flat market economics in 2026. No “from $X” marketing fluff. Fixed-price contracts on signed scope.
Three honest price bands based on real Perth granny-flat market economics in 2026. No “from $X” marketing fluff. Fixed-price contracts on signed scope.
Conversion
$80k–$140k
3–4 months · existing structure
Converting a garage, studio or outbuilding to a compliant ancillary dwelling. Lowest cost path. Full kitchen, bathroom, services, R-Codes compliance.
Standard
$140k–$220k
4–6 months · most popular
Standard new-build granny flat — 60–70m², 1–2 bed, attached or detached. Council-approved, R-Codes compliant. Most-quoted band Perth-wide.
Premium
$220k+
5–8 months · larger spec
Larger ancillary dwelling — up to 120m² where council permits, 2 bed, premium specification. Investment-grade or multi-generational use cases.
How we work
Five steps from brief to handover.
Granny flats have one defining characteristic: the council and R-Codes assessment decides what you can build before any design begins. Our process loads that work upfront.
How we work
Five steps from brief to handover.
Granny flats have one defining characteristic: the council and R-Codes assessment decides what you can build before any design begins. Our process loads that work upfront.
Quality criteria
What separates good
granny flat wide-
Perth.
The unglamorous things that decide whether a granny flat performs for thirty years or starts to fail at year ten. None of these show in display photos. All of them matter.
Compliance
R-Codes compliant.
Designed within the WA Residential Design Codes envelope from day one — not retrofitted to fit after a council knockback. Setbacks, coverage, parking all assessable.
Insurance
Statutory home warranty.
Home-warranty insurance under the WA Home Building Act applies on residential builds over $20,000. Taken out before site start, paid by us.
Services
Separately metered.
Power, water and sewer designed for separate metering where the dwelling will be rented. Cheaper to retrofit at design than after handover.
Privacy
Designed for two households.
Window placement, fencing, separate access — designed so two households can share a block without living in each other’s pockets. Often overlooked, always missed.
Energy
7-star NatHERS standard.
National Construction Code 7-star energy rating applies to ancillary dwellings. Insulation, glazing, orientation specified at design — not value-engineered out at quote.
Materials
For WA conditions.
Galvanised framing, UV-stable cladding, marine-grade fittings near the coast. Specified for forty-degree summers and Indian Ocean storms.
Quality criteria
What separates good
granny flat wide-
Perth.
The unglamorous things that decide whether a granny flat performs for thirty years or starts to fail at year ten. None of these show in display photos. All of them matter.
The unglamorous things that decide whether a granny flat performs for thirty years or starts to fail at year ten. None of these show in display photos. All of them matter.
Compliance
R-Codes compliant.
Designed within the WA Residential Design Codes envelope from day one — not retrofitted to fit after a council knockback. Setbacks, coverage, parking all assessable.
Insurance
Statutory home warranty.
Home-warranty insurance under the WA Home Building Act applies on all residential builds over $20,000. Taken out before site start, paid by us as the licensed builder.
Services
Separately metered.
Power, water and sewer designed for separate metering from day one where the dwelling will be rented. Cheaper to retrofit at design than after handover.
Privacy
Designed for two households.
Window placement, fencing, separate access — designed so two households can share a block without living in each other’s pockets. Often overlooked, always missed.
Energy
7-star NatHERS standard.
National Construction Code 7-star energy rating applies to ancillary dwellings. Insulation, glazing, orientation specified at design — not value-engineered out at quote.
Materials
For WA conditions.
Galvanised framing, UV-stable cladding, marine-grade fittings near the coast. Specified for forty-degree summers and Indian Ocean storms — not display-home photos.
Common questions
Granny flats Perth — the questions we get.
The questions Perth homeowners ask before briefing a granny flat build. Plain answers, plain English, no salesy hedge.
Brief us on a granny flat
Tell us about your Perth granny flat.
A short brief so we can come back with an informed first call. The builder reads every brief personally — replies within one business day. No commitment beyond an honest conversation.