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© 2026 GFK Homes — Granny Flat Kits AU. Backed by LINKUP AI PropTech Group.
Free Planning ToolPublished February 28, 2026

Granny Flat Cost Calculator

Build a realistic budget range before you request a quote. This calculator breaks your estimate into the cost buckets buyers most often miss, so you can see where uncertainty sits and plan next actions with fewer surprises.

Start with the calculatorRequest a site-specific quote

Bucket-level transparency

See exactly how unit price, freight, site works, approvals, utilities, and contingency affect your range.

Scenario-first workflow

Use ready presets for investor, family, and regional setups before customizing your own assumptions.

Quote-ready next steps

Move directly from estimate output to a site-specific quote with your planning context preserved.

States & territories modeled

8

NSW, VIC, QLD, WA, SA, TAS, ACT, and NT multipliers supported.

Scenario presets

3

Investor fast-start, family balance, and regional max-space templates.

Budget buckets

7

Unit, freight, site works, approvals, utilities, add-ons, and contingency.

Granny Flat Cost Estimator

Input your scenario, then generate a transparent budget range across project cost buckets.

Example scenarios

No estimate yet

Empty state: choose a scenario or keep defaults, then run estimate.

How to use this calculator

  1. 1. Pick unit type, bedroom plan, state, area type, and site complexity.
  2. 2. Set approval pathway and utilities scope, then toggle optional add-ons.
  3. 3. Run the estimate and compare total range against each cost bucket.
  4. 4. Use the boundary warning and assumptions to prepare a practical quote brief.

Ready for a lender-facing budget review?

Use your estimate as a starting point, then send postcode, access constraints, and timeline so we can validate assumptions before formal quoting.

Request a quote reviewRecheck calculator inputs

Planning a caravan park expansion portfolio?

After checking total budget buckets, run a commercial scenario with occupancy and nightly-rate assumptions in the B2B parks planner.

Open B2B parks plannerOpen acreage farmstay plannerOpen farm worker housing plannerOpen mining camps plannerOpen property developers plannerOpen vineyard wedding plannerView trade inventory

Assumptions and limitation notice

These ranges are decision-support estimates, not financial, tax, or legal advice. They exclude finance interest, legal review, and tenant-ready furnishing scope. Verify final costs through certifier, utility providers, and site-specific quote documentation.

Reference baseline sources

Source set reviewed and aligned on February 28, 2026 for market range benchmarking. We use these references for context only and do not claim equivalence with site-specific quotes.

  • Hipages: how much does a granny flat cost
  • Canstar: granny flat cost guide
  • TradieVerify: NSW granny flat estimator reference
  • TradieVerify: VIC granny flat estimator reference
  • Kit Homes AU: price calculator reference

Cost calculator FAQs

Is this estimate accurate enough for final contract budgeting?

No. This calculator is a planning tool for early feasibility only. Final contract pricing depends on site access, engineering details, certifier/council requirements, utility provider conditions, and confirmed inclusions.

Why do regional and metro totals differ?

Location changes freight, access logistics, and trade availability. Regional projects can carry higher logistics ranges, while metro projects may have stronger labor and compliance cost pressure.

What does the boundary alert mean?

Boundary alerts indicate outputs at unusually low or high ranges based on your selected inputs. They are prompts to re-check assumptions, not approvals or guarantees.

Can I still request a quote if I do not know every input?

Yes. Use the estimate as a first pass, then submit your postcode and property context in the quote form. Our team can refine assumptions and identify missing scope items.

Related planning pages

Continue from budget planning into return modeling, layout comparison, and compliance context.

ROI Calculator

Test rental yield and payback ranges after estimating total project budget.

Floor Plans

Compare layout options and space envelopes before locking scope.

Finance Guidance

Review payment pathways and documentation readiness for lenders.

Policy Research

Understand state-level approval reforms and feasibility risks.

Need a quote tied to your exact site constraints?

Share postcode, access conditions, preferred model, and target timeline. We will map this estimate to a practical quote scope.

Get my site-specific quote