Understanding the Basics of Home Loan Structure Options

A home loan structure determines how you repay the principal, manage interest, and access features like offset accounts and redraw.

The right structure depends on whether you're buying to live in or invest, how long you plan to hold the property, and how much cash you need to keep on hand. You can split your loan across multiple structures, or you can choose a single setup and adjust it later if your lender allows. Either way, the decision you make when you apply shapes your repayments and borrowing options for years to come.

Principal and Interest vs Interest Only

A principal and interest loan requires you to repay both the amount you borrowed and the interest charged on that amount with each monthly repayment. An interest only loan lets you pay just the interest for a set period, typically one to five years, after which the loan reverts to principal and interest repayments.

Owner-occupiers generally use principal and interest structures because they build equity faster and reduce the total interest paid over the life of the loan. Interest only structures are more common among investors who want to maximise tax deductions on interest and free up cash for other investments, though this approach delays equity accumulation and can lead to higher repayments once the interest only period ends.

Consider a buyer purchasing at the suburb's current median in Augustine Heights. If they structure the loan as principal and interest from the outset, the monthly repayment at current variable rates will include a portion that reduces the outstanding balance. Over a typical 30-year term, that early equity accumulation can improve borrowing capacity if they need to refinance or purchase a second property. If they choose an interest only period instead, their monthly repayments will be lower during the interest only phase, but they will owe the same amount at the end of that period as they did on day one.

Fixed Rate, Variable Rate and Split Structures

A variable rate loan tracks movements in the lender's standard variable rate, which typically moves in response to changes in the RBA cash rate. A fixed rate loan locks your interest rate for a chosen term, most commonly one to five years. A split loan divides your total borrowing between a fixed portion and a variable portion, each with its own rate and features.

Variable rate loans offer full access to offset accounts and unlimited additional repayments without penalty. Fixed rate loans provide certainty over repayments for the fixed term, but most lenders restrict offset access and cap additional repayments during that period. If you repay a fixed rate loan early or refinance before the fixed term ends, break costs may apply depending on the difference between your fixed rate and the lender's current cost of funds.

A split structure gives you partial rate certainty while keeping part of the loan on a variable rate with full offset and redraw access. In our experience, buyers who expect income to fluctuate or who plan to make lump sum repayments from bonuses or property sales typically keep at least half the loan on a variable rate. Those who prefer stable repayments and don't expect to pay down the loan ahead of schedule may fix a larger portion or the entire amount, accepting the trade-off on flexibility.

How Offset Accounts Work Across Different Structures

An offset account is a transaction account linked to your home loan that reduces the interest charged on your loan balance by the amount held in the offset account. If you have a loan balance of $800,000 and $50,000 in your offset account, you pay interest on $750,000.

Offset accounts are available on most variable rate owner occupied and investment loans, though coverage varies between lenders. Fixed rate loans either do not offer offset functionality or offer only a partial offset during the fixed term. Some lenders allow 100% offset on fixed rate loans but charge a higher fixed rate to do so. Most lenders charge a monthly account fee for an offset facility, typically between $10 and $20 per month, though some packages bundle the offset at no additional cost.

As an example, a buyer in Bellbird Park with $40,000 in savings after settlement could place that amount in an offset account linked to their variable rate loan rather than paying it directly off the principal. The offset saves interest at the loan rate while keeping the cash accessible if they need it for renovations, school fees or emergency expenses. If the same buyer had chosen a fully fixed loan structure, that $40,000 would sit in a standard savings account earning a lower rate with no offset benefit.

Portable Loans and Switching Between Properties

A portable loan allows you to transfer your existing home loan to a new property without triggering break costs or discharge fees, though the feature is more common on variable rate products than fixed. Most lenders require the new property to settle before or on the same day as the sale of the existing property for portability to apply.

Portability can be useful if you're upgrading from a smaller home to a larger one in a nearby suburb and want to retain your current loan rate and structure. It does not exempt you from a fresh serviceability assessment if you need to borrow additional funds for the new property, and the lender will require a new valuation and standard settlement process. If you are moving from an owner occupied home loan to an investment property or vice versa, you will need to notify your lender as this affects the interest rate and tax treatment, and portability may not be available on those terms.

Structuring for Tax and Borrowing Capacity

If you are purchasing an investment property, the structure you choose affects the deductibility of interest and your ability to borrow again in future. Interest on an investment loan is generally tax deductible against rental and other income, provided the loan is used to purchase, construct or improve the income-producing property. Repaying principal reduces your deductible interest over time, which is why many investors use interest only structures during the ownership phase and direct surplus cash into offset accounts instead.

Keeping funds in offset rather than paying down the loan preserves your deductible debt and keeps cash accessible if you want to purchase another property. If you later convert an investment property to your principal place of residence or sell it and use the equity to buy an owner occupied home, the tax treatment of the loan changes and any interest on the portion used for non-income-producing purposes is no longer deductible. Lenders assess your borrowing capacity based on the repayment type you select at application, so choosing an interest only structure on an investment loan may allow you to borrow more than a principal and interest structure would, though this depends on your income and existing commitments.

Changing Structure After Settlement

Most lenders allow you to switch from interest only to principal and interest, or from variable to fixed, after settlement, though some changes require a formal loan variation and may attract fees. Switching from principal and interest to interest only, or refinancing to access equity, requires a fresh serviceability assessment and in some cases a new valuation. Lenders will apply the current serviceability buffer and lending policies at the time of the variation, which may differ from the settings that applied when you first borrowed.

If you want to move from a fixed rate to a variable rate before the fixed term ends, break costs will apply in most cases. Moving from variable to fixed does not attract break costs, though the new fixed rate will be the lender's current rate at the time you lock in, not the rate available when you first settled. If your circumstances or property plans have changed since you took out the loan, a loan health check with a broker can help you assess whether a structure change or refinance makes sense given the costs and your current borrowing position.

Call one of our team or book an appointment at a time that works for you. We'll compare your current structure against what's available now and walk through the numbers with you directly.

Frequently Asked Questions