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How the numbers work: buying a home
48 worked calculations taken from the guides on this subject, each shown a line at a time with the figure it arrives at.
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First Home Buyer Guide
Deposit Requirements
- Minimum 10% deposit (Low Equity Loan - LMI applies)
- Recommended 20% deposit (No LMI, better rates)
- Example: $600K home needs $120K for 20% deposit
Deposit Requirements
- Minimum 5% deposit for new builds
- Government supports new build lending
- Example: $700K new build needs $35K for 5%
Loan to Value Ratio (LVR)
- LVR = Loan Amount ÷ Property Value × 100
- Example: Borrow $480K on $600K home
- LVR = $480,000 ÷ $600,000 × 100 = 80%
- 20% deposit = 80% LVR
KiwiSaver Withdrawal
- Must leave $1,000 in KiwiSaver account
- Can withdraw all member contributions + returns
- Example: $45,000 in KiwiSaver, withdraw $44,000
Borrowing Capacity
- Combined household income
- Job stability (probation periods matter)
- Other income sources (rental, side business)
Borrowing Capacity
- Total debt ÷ Annual income < 6x (NZ guidance)
- Example: $100K income → max $600K total debt
- Includes car loans, student loans, credit cards
Borrowing Capacity
- Current rate: 6.5%
- Test rate: 8.5-9.0% (stress test)
- Must afford repayments at test rate
- Ensures buffer if rates rise
Example 1: Standard Purchase - Auckland
- Purchase price: $750,000
- 20% deposit: $750,000 × 0.20 = $150,000
- Loan amount: $750,000 - $150,000 = $600,000
- LVR: 80% (no LMI)
Example 1: Standard Purchase - Auckland
- Couple, both 5+ years in KiwiSaver
- Partner A KiwiSaver: $38,000 (withdraw $37,000)
- Partner B KiwiSaver: $42,000 (withdraw $41,000)
- Total KiwiSaver help: $78,000
Example 1: Standard Purchase - Auckland
- Deposit needed: $150,000
- From KiwiSaver: $78,000
- Additional savings needed: $72,000
- Plus costs: $8,000
Total cash needed: $80,000
Example 1: Standard Purchase - Auckland
- Loan: $600,000
- Monthly repayment: $3,792
- Annual repayments: $45,504
Example 2: Low Deposit Purchase
- Purchase: $600,000
- 10% deposit: $60,000
- Loan: $540,000
- LVR: 90% (LMI applies)
Example 2: Low Deposit Purchase
- Standard rate: 6.5%
- LMI premium: +0.75%
- Effective rate: 7.25%
- Monthly repayment: $3,686
- Annual: $44,232
Example 2: Low Deposit Purchase
- At 6.5% (no LMI): Monthly $3,408, annual $40,896
- At 7.25% (with LMI): Monthly $3,686, annual $44,232
LMI costs extra: $3,336/year
Example 2: Low Deposit Purchase
- Need to reduce LVR to 80%
- Target loan: $480,000 (80% of $600K)
- Current loan: $540,000
- Pay down: $60,000 to reach 80% LVR
- At $500/month extra: Takes 10 years
- At $1,000/month extra: Takes 5 years
Example 3: New Build Purchase
- New build price: $720,000
- 5% deposit: $36,000
- Loan: $684,000
- LVR: 95%
Example 3: New Build Purchase
- Couple, 5+ years each
- KiwiSaver withdrawal: $50,000
- Total from KiwiSaver: $50,000
Example 3: New Build Purchase
- Deposit needed: $36,000
- From KiwiSaver: $50,000
- Surplus: $14,000
- Use surplus for: Costs ($8K) + emergency fund ($6K)
Example 5: Paying Off Faster
- Monthly: $3,476
- Total paid: $1,251,360
- Interest: $701,360
Example 5: Paying Off Faster
- Monthly: $3,740
- Total paid: $1,122,000
- Interest: $572,000
Saves $129,360!
Example 5: Paying Off Faster
- Monthly: $4,188
- Total paid: $1,005,120
- Interest: $455,120
Saves $246,240!
🌍 Real-World First Home Buyer Stories
- Target: 2-bed apartment, $650,000
- Saved: $55,000 cash
- KiwiSaver: $35,000 (Alex), $32,000 (Jordan)
- Both in KiwiSaver 5+ years
🌍 Real-World First Home Buyer Stories
- 20% deposit needed: $130,000
- KiwiSaver withdrawn: $66,000 ($33K each)
- Cash used: $55,000
- Subtotal available: $121,000
- Shortfall to save: $9,000 deposit + $8,000 costs = $17,000
🌍 Real-World First Home Buyer Stories
- Single income = lower borrowing capacity
- Bank approved: $500,000 loan max
- With 20% deposit: $625,000 max purchase
🌍 Real-World First Home Buyer Stories
- New build townhouse: $680,000
- 5% deposit allowed: $34,000
- Loan: $646,000 (95% LVR)
- Bank approved due to new build exception
🌍 Real-World First Home Buyer Stories
- Savings: $15,000
- KiwiSaver: $48,000 (withdraw $47,000)
- Total: $62,000
- Deposit: $34,000
- Costs: $9,000
- Remaining: $19,000 (emergency fund + furniture)
- Combined income: $120,000
- Bank approved: $650,000 loan
- Purchased: $800,000 home (max budget)
- Monthly mortgage: $4,108
- Left no buffer for costs
- Saved for 4 years
- Target: $550,000 purchase
- Saved: $130,000 (23% deposit!)
- Well above 20% requirement
- Paid down to $350,000
- House now worth $620,000
- Equity: $270,000 (43%)
- Considering investment property
New Build vs Existing Home
🔢 Four worked New Zealand examples
- New build deposit: $700,000 × 20% = $140,000, so the loan is $560,000
- Existing home deposit: $750,000 × 20% = $150,000, so the loan is $600,000
The existing home needs $10,000 more deposit
🔢 Four worked New Zealand examples
- New build: $560,000 × 6.0% = $33,600
- Existing home: $600,000 × 6.0% = $36,000
The existing home costs $2,400 more interest in year one
🔢 Four worked New Zealand examples
- New build: about $1,000 per year = $5,000, much covered by guarantee
- Existing home: about $5,000 per year = $25,000 (repaint, roof, insulation top-up)
- Existing home also pays a pre-purchase building inspection of about $800
Five-year maintenance gap: $25,000 - $5,000 = $20,000 in the new build's favour
🔢 Four worked New Zealand examples
- A 20% deposit would be $600,000 × 20% = $120,000
- Priya's deposit: $80,000 ÷ $600,000 = 13.3%
She needs the bank to lend above 80%, which it can only do for up to 25% of its new owner-occupier lending, so approval is not guaranteed
🔢 Four worked New Zealand examples
- New-build lending is exempt from the LVR restrictions, so the bank is not using its limited high-LVR quota
- The First Home Loan allows a 5% deposit: $600,000 × 5% = $30,000
- Priya's $80,000 (13.3%) is well above the 5% minimum
Her loan would be $600,000 - $80,000 = $520,000, and approval is easier because the exemption applies
- Deposit on signing: $750,000 × 10% = $75,000
- Balance on completion: $675,000
No construction-period interest, they keep renting until handover
- Land settles first, so $350,000 is drawn from day one
- Interest on the land for 9 months: $350,000 × 6.0% × 9/12 = $15,750
- Build drawdowns average about $200,000 across the build
- Interest on drawdowns: $200,000 × 6.0% × 9/12 = $9,000
Construction-period interest: $15,750 + $9,000 = $24,750, plus rent while building
- For property sold on or after 1 July 2024, the bright-line test is 2 years for both new builds and existing homes
- If the property is his main home, the bright-line test generally does not apply at all
The old 5-year (new build) versus 10-year (existing) split no longer exists
- Buys an existing rental for $750,000, sells 18 months later for $820,000
- Taxable gain: $820,000 - $750,000 = $70,000
- Tax at his 33% marginal rate: $70,000 × 33% = $23,100
A new build sold in the same window would be taxed the same way
Buying a Home With Family
🔢 Four worked New Zealand examples
- Loan split equally: $600,000 / 2 = $300,000 each
- Aroha's total contribution: $120,000 deposit + $300,000 loan = $420,000
- Mia's total contribution: $40,000 deposit + $300,000 loan = $340,000
- Aroha's share: $420,000 / $760,000 = 55.3%
Mia's share: $340,000 / $760,000 = 44.7%
🔢 Four worked New Zealand examples
- The right of survivorship applies, so Tama's interest passes automatically to Rewi
- Rewi becomes the sole owner of the whole $800,000 home
Tama's daughter receives nothing from the home, whatever his will says
🔢 Four worked New Zealand examples
- Tama's 50% share passes under his will to his daughter
- The daughter inherits an interest worth about $400,000
She and Rewi now co-own the home, each holding half
- Equity: $900,000 value − $450,000 mortgage = $450,000
- Sam's share: $450,000 / 3 = $150,000
Priya and Jack can buy Sam's third for $150,000
- The home is the couple's family home, so the $150,000 equity is relationship property
- Relationship property is generally split 50/50: $150,000 / 2 = $75,000 each
About $50,000 of the parent's $100,000 effectively ends up with the ex-partner
- The $100,000 loan is a debt repaid to the parent before equity is divided
- Remaining equity to split: $150,000 − $100,000 = $50,000
- Split 50/50: $50,000 / 2 = $25,000 each
The parent's $100,000 is returned in full
Kainga Ora First Home Loan Guide
A 5% Deposit, Not 20%
- A home costs $600,000
- A standard 20% deposit would be $120,000
- With a First Home Loan, a 5% deposit is $30,000
- That much smaller deposit can be reachable years sooner
You Still Have to Afford It
- The First Home Loan reduces the deposit hurdle to 5%
- The lender still checks you can afford the repayments
- A smaller deposit means a larger loan and higher repayments
- So budget carefully for the ongoing cost, not just getting in
A Simple Action Plan
- 1. Check the current income limits for your situation
- 2. Confirm you are a first home buyer who will live in the home
- 3. Build your deposit, including any KiwiSaver withdrawal
- 4. Apply through a participating lender, not Kainga Ora
- 5. Check you can afford the repayments on the larger loan
- 6. Compare buying now with saving for a bigger deposit
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Every worked calculation
Workings are taken from the guides listed above and are worked examples for education, not advice. Figures used in an example were current when the guide was written; the guide holds the maintained figure. Last reviewed 2026-09-06. See also every question the site answers and the guides.