Building a Property Portfolio: Getting the Lending Strategy Right

By Jason Given · 2026-08-16 · 8 min read

Why property 2, 3, and 4 are harder than property 1

Your first investment property is relatively straightforward. One loan, one lender, one set of policies. You find a property, get approved, settle, and start collecting rent. The lending side is no more complex than buying a home to live in.

Each additional property changes that equation. More debt to service, more lender policies to deal with, more risk of cross-collateralisation tying your portfolio together in ways that limit your flexibility. The complexity compounds with every purchase.

This is where the lending strategy matters as much as the property selection itself. A good property purchased with a bad loan structure can reduce your borrowing capacity for the next purchase by tens of thousands of dollars. Get the structure wrong early in your portfolio and your capacity for property three or four evaporates before you get there.

The investors who build portfolios of four, five, or more properties are not necessarily earning more than everyone else. They are structuring their lending strategically from day one.

The multi-lender strategy

One of the most effective strategies for portfolio building is spreading your loans across multiple lenders. It sounds counterintuitive - why not keep everything simple with one bank? The answer comes down to how lenders assess your borrowing capacity.

Each lender only fully assesses the debt they hold. If Lender A holds $500,000 and Lender B holds $400,000, neither sees the other's debt in the same way as if one lender held the full $900,000. Different lenders also use different serviceability calculators, different expense benchmarks, and different policies for how they treat rental income. By placing each property with the lender whose policies work best for that purchase, you can maintain more borrowing capacity across your total portfolio.

Using multiple lenders also avoids cross-collateralisation - where one lender holds security over multiple properties. That is a trap worth avoiding entirely, and it deserves its own section.

Lendology sequences your lenders strategically. We place each property with the lender that gives the best rate, policy fit, and borrowing capacity for that specific purchase - while preserving your capacity for the next one.

Cross-collateralisation: the trap to avoid

Cross-collateralisation means linking multiple properties as security for one loan facility. Banks love it because it gives them control over your entire portfolio. For you as an investor, it creates problems that only become apparent when you try to do something with one of those properties.

The first problem is control. With cross-collateralised loans, you cannot sell one property without the lender's consent. They may require a revaluation of your remaining properties before releasing the security. If property values have dropped, they might not release the title at all - even if the property you are selling has plenty of equity on its own.

The second problem is refinancing. If you want to move one property to a different lender for a better rate, the cross-collateralisation makes it significantly more complex. The existing lender needs to restructure the remaining facility, revalue the remaining properties, and agree to release one security. Some will not cooperate willingly.

The third problem is contagion. If one property drops in value, it affects your entire facility. The lender looks at the combined loan-to-value ratio, not each property individually. A single underperforming property can trigger margin calls or restrict your ability to draw on equity elsewhere in your portfolio.

The solution is simple: always structure standalone securities. Each property should be secured only against its own loan. Lendology never recommends cross-collateralisation.

Interest-only for portfolio building

During the acquisition phase of building a portfolio, interest-only loans make sense for investment properties. The logic is straightforward: lower monthly repayments preserve cash flow and maximise your borrowing capacity for the next purchase.

With an interest-only loan, you are paying only the interest on the debt - not reducing the principal. This means your monthly repayments are significantly lower than a principal and interest loan. For a $500,000 loan at 6.5%, the difference is roughly $900 per month. Across a portfolio of three properties, that is $2,700 per month in cash flow that can be directed toward the deposit for property four.

There is also a tax benefit. Interest on investment loans is fully tax deductible. Principal repayments are not. So during the acquisition years, interest-only loans are more tax efficient.

The trade-off is that you are not building equity through repayments - only through capital growth. And interest-only periods are not permanent. They typically last 5 years before reverting to principal and interest, at which point your repayments increase substantially.

The strategy that works for most portfolio builders: use interest-only during the acquisition years when you are actively buying, then switch to principal and interest once the portfolio is at your target size. Lendology structures IO terms that align with your acquisition timeline so you are not caught off guard when rates revert.

Serviceability across a portfolio

Every new property you buy adds rental income to your financial position. But it also adds debt. And the way lenders assess this equation makes each additional property harder to finance than the last.

First, lenders only count 80% of gross rental income for serviceability purposes. The other 20% is a buffer for vacancies and expenses. So if a property rents for $500 per week, the lender only counts $400.

Second, the APRA 3% stress test buffer applies to all of your debt - not just the new loan. This is the critical point. Every existing loan in your portfolio is assessed at 3% above the actual rate. If your actual rate is 6.5%, the lender models your repayments at 9.5%.

Here is what that looks like in practice: 3 properties with $1.5 million in total debt. At the actual rate of 6.5%, the annual repayments are manageable. But at the stress test rate of 9.5%, the monthly repayments jump to approximately $12,700. Your income must cover this amount plus living expenses, plus the expenses on all three properties. That is a high bar for most households.

This is exactly why lender selection and loan structure become critical as your portfolio grows. The right lender for property four might be completely different from the right lender for property one. Lendology models your maximum portfolio capacity based on your current income and debt position, then sequences each purchase to preserve as much borrowing power as possible.

Adelaide as a portfolio market

Adelaide's yield-to-price ratio is among the best in Australia for portfolio builders. The numbers tell the story: entry prices are significantly lower than Sydney and Melbourne, which means each property requires less borrowing capacity. You can fit more properties into the same income envelope.

Rental demand is strong. Vacancy rates have been consistently under 1% across most Adelaide suburbs, which means reliable income and minimal void periods. For portfolio serviceability, low vacancy rates translate directly into more predictable cash flow and stronger lending applications.

Capital growth has also outperformed most other capital cities over the past three years. Adelaide was once considered a slow-growth market, but recent performance has rewritten that assumption. For investors who bought two or three years ago, the equity growth has been substantial enough to fund the deposit for the next purchase.

For portfolio builders, the practical advantage is clear: Adelaide allows more properties per dollar of borrowing capacity than the east coast markets. An investor who might manage two properties in Sydney could potentially hold four or five in Adelaide, with better yield and comparable growth prospects.