How to Use Your Home’s Equity to Buy an Investment Property Without Cash Savings
A quick heads-up: The information in this article is designed as a general educational guide only and does not constitute personalised financial, tax, or legal advice. Because everyone's situation is unique (and bank policies change frequently), we recommend speaking with a licensed Financial Adviser to see how this applies to your specific circumstances. For full transparency on our terms of service, how we are remunerated by lenders, and any specific situations where a fee may apply, please read How We Get Paid.
If you have owned a home in New Zealand for more than a few years, you likely have a highly effective financial tool sitting right beneath your feet: usable equity.
As property values rise and you slowly pay down your mortgage, the gap between what your house is worth and what you owe the bank grows. Many Kiwis assume that wealth is locked away until they sell the property. In reality, banks allow you to 'unlock' that exact wealth and use it as the deposit for a second property.
This strategy—known as leveraging—is the exact mechanism behind the 'Bank of Mum and Dad', and it is the primary way everyday New Zealanders build property portfolios without needing to save up a second cash deposit from scratch.
Here is exactly how the maths works, the strict rules the banks enforce, and how to calculate your own purchasing power.
Total equity versus 'usable' equity
Your total equity is a simple calculation: it is the current market value of your home, minus your current mortgage balance.
However, banks will never let you borrow against 100% of your home's value. Under standard lending rules in New Zealand, banks generally require a mandatory 20% safety buffer (or reserve) to remain untouched in your primary residence. (Note: this assumes you will continue living in your current home; the maths is slightly different if it is becoming a rental).
See the numbers in action
Instead of doing the maths on paper, use the tool below to see exactly how leveraging works in the real world.
Adjust the inputs to match your current property value and mortgage. Watch how the bank 'tops up' your loan, physically releasing your usable equity so it can be transferred over as the deposit for an investment property.
(Toggle the 'New Build' switch to see how the Reserve Bank's 10% deposit exemption can increase your purchasing power).
The four steps to buying an investment property
As demonstrated in the tool above, buying an investment property using equity is usually structured as a clear, four-step process.
- The valuation and setup: First, we must prove to the bank exactly what your home is worth today. We typically order an automated desktop valuation (AVM) or a full Registered Valuation to confirm your total equity and establish that strict 20% safety reserve line.
- Restructuring the family home (the top-up): You do not actually sell any part of your house. Instead, we restructure your existing loan. We ask the bank to increase (top up) the mortgage on your family home by an amount equal to your usable equity. The bank approves this increase as a separate loan split, making those funds ready to cover the deposit and settlement of the rental property
- The deposit transfer: That newly released cash is now your deposit. You transfer it out of your account to act as the required deposit for the investment property (typically 30% for existing homes, or 10% for new builds).
- Securing the investment mortgage: Because you now have a cash deposit ready to go, the bank provides a completely separate, standalone mortgage secured directly against the new rental property to cover the remaining purchase price.
The final hurdle: servicing the debt
Our interactive tool shows you how to unlock the deposit needed for an investment. However, having the deposit is only half the battle.
How rental income helps
The great news for investors is that you do not have to service the second mortgage entirely on your own.
Try our borrowing power calculator here.
Pro tip: the two bank rule
When securing your new investment mortgage, we strongly recommend using a different bank than the one holding your family home mortgage.
(Read more about the split banking strategy here).
Ready to find out what you can afford?
Calculating usable equity is straightforward; proving to the bank that you can service two mortgages is where the real work happens.
Do you have a more complex equity situation? Will your current home become a rental, or do you already have different properties with different lenders? (Try our comprehensive Usable Equity Calculator for a highly detailed breakdown based on current interest rates).
When you are ready to make a move, we specialise in structuring investment finance. We can run the exact internal servicing calculators the banks use, factor in projected rental yields, and tell you down to the dollar what your true purchasing power is—before you ever pay for a valuation or sign a contract.
Book a free investment strategy session with a Home Loan Factory adviser today
Frequently asked questions
How much equity do I need to buy a second house in NZ?
You generally need enough usable equity in your current home to cover a 30% deposit on an existing investment property, or a 10% deposit if you are purchasing a new build. To access this usable equity, you must leave a minimum 20% equity buffer untouched in your primary home.
Can I use equity from my home as a deposit?
Yes. By restructuring your current home loan, the bank can increase your mortgage up to 80% of your property's value. The cash released from this top-up can then be used as the deposit for a second property.
How does the Bank of Mum and Dad work in NZ?
The 'Bank of Mum and Dad' typically works through this exact leveraging strategy. Parents use the usable equity in their own family home to provide the cash deposit for their child's first home, often acting as guarantors to satisfy the bank's security requirements.
Does rental income count towards a mortgage application?
Yes. When buying an investment property, New Zealand banks will use a scaled percentage (typically 70% to 75%) of the property's projected gross rental income and add it to your personal income to help you pass the mortgage servicing test.
