Beginner's Guide to Fixed Rate Loans for ADF First Buyers

A fixed rate locks in your repayment for a set period, and the term you choose should match how long you expect to stay put.

For an ADF member buying a first home, that second part matters. Postings, courses and deployments can change your plans faster than a civilian's. A fixed term that is too long can become expensive to leave. One that is too short gives you less certainty. This guide covers how to pick the length, and what to ask your lender before you commit.

What Is a Fixed Interest Rate on a Home Loan?

A fixed interest rate keeps your rate and repayment the same for an agreed term, so your repayment does not move when the market does. When the term ends, most loans move to the lender's variable rate unless you choose a new fixed term, so confirm this in your loan documents.

A variable interest rate can move up or down over the life of the loan. Fixed gives certainty, and variable gives flexibility. You can also split a loan so part is fixed and part is variable.

The trade-off with fixing is that you may lose features. Some lenders limit extra repayments on the fixed portion, and not every lender offers an offset account or redraw on fixed loans. If you want to pay the loan down quickly, ask about these limits first.

How Much Could a Rate Change Affect Your Repayments?

On a $500,000 loan over 30 years at the illustrative rate of 6.75%, principal and interest repayments come to about $3,243 a month. If the rate were 1 percentage point higher at 7.75%, the same loan would cost about $3,582 a month. That is roughly $339 more each month.

These figures are illustrative only and are not a current offer. The point is that a fixed rate protects you from that jump during the fixed term. It also means you will not benefit if rates fall. Use our borrowing capacity calculator to test your own numbers.

Which Fixed Term Suits a Posting Cycle?

A shorter fixed term, often one to three years, usually suits members who might be posted away, while a longer term suits members who expect to stay. The right length depends on how likely you are to sell, refinance or rent out the home before the term ends.

The main risk is break costs. If you repay the loan, refinance or sell during the fixed term, your lender may charge a fee. The amount depends on your lender, your remaining term and how rates have moved since you fixed. Ask your lender how they calculate it before you sign.

As an example, consider an ADF member in Alsace buying a first home who expects a posting in about three years. They borrow $500,000 and fix $300,000 for two years, leaving $200,000 variable with an offset account. The fixed portion gives a steady base repayment while they settle in. The variable portion lets them pay extra from their savings and any extra pay without restrictions. When the two years end, they review the loan before it rolls over. If the posting comes early, any break cost applies only to the fixed portion, not the whole loan. The cost is a lower share of certainty, and they accept that in return for flexibility.

How Do First Home Buyer Concessions Fit With Fixing?

Your fixed rate choice is separate from the grants and duty relief you may be entitled to, but those savings can change how much you borrow. In Queensland, a first home buyer purchasing a new home may receive a $30,000 first home owner grant where the home is valued under $750,000. The grant is not available for established homes.

For first home buyer stamp duty concessions, Queensland applies no duty on an established home valued at $700,000 or under for eligible buyers. A full concession applies to new homes and vacant land for a first home buyer. For transactions entered into from 1 August 2026, each buyer must be an Australian citizen or permanent resident, or a specified foreign retiree, to claim these concessions. Confirm your eligibility with the Queensland Revenue Office or your solicitor before you sign a contract.

Can You Fix a Rate With a 5% Deposit or Help to Buy?

You may be able to, but the schemes do not set the loan features, and the participating lender provides the loan. Loan features such as fixed rates, offset accounts and redraw depend on the participating lender, so ask the lender directly.

Under the 5% Deposit Scheme, you must move in within six months of settlement and keep living there while the backing applies. If you move out early, the lender may require you to pay lenders mortgage insurance. With a posting on the horizon, that is a bigger issue than your fixed term. Read how our 5% deposit scheme guidance for ADF members works before you decide.

Help to Buy is a separate scheme, and applicants must meet an income threshold and use a participating lender. Housing Australia states it may approve temporary absences, including ADF postings, for Help to Buy participants. Details are on our Help to Buy scheme page.

Get Pre-Approval Before You Choose a Fixed Term

Pre-approval shows you what you can borrow, and it lets you compare fixed and variable structures with real numbers before you bid. Housing Australia advises that Help to Buy buyers should not put down a deposit or bid at auction without conditional approval, so sequence matters.

When you have your pre-approval, work out how long you expect to hold the loan. Then match the fixed term and the split to that. Read our guide on getting loan pre-approval to see how it works. If you already have a loan and your fixed term is ending, use the fixed rate expiry calculator to see what happens next.

Our team can walk you through buying your first home with the Alsace area in mind. Call one of our team or book an appointment at a time that works for you, and we will help you pick a fixed term that fits your service.

Frequently Asked Questions