Super-for-Mortgage Plan: $172k Offset Cuts Repayments 33%

The REIA case study is the clearest numbers-based pitch yet for the offset model. Separate modelling by actuary Jonathan Ng, cited in the same report, found a $40,000 offset against an $800,000 unit loan would save $164,000 in interest over the life of the loan and pay it off 3.6 years early. Those figures explain why the proposal has traction among politicians responding to five interest rate rises this year that have pushed mortgage rates to around 6.5%.

Labor and the Greens pushed back hard at the inquiry, flagging two risks: upward pressure on home prices, and smaller retirement balances for people who use the scheme. The Grattan Institute told the inquiry that offset funds forgo compounding growth, a concern echoed by independent economist Saul Eslake, who told realestate.com.au the policy would likely leave most users worse off over their lifetime.

Why the Maths Rarely Favours the Offset

Eslake's objection is a straightforward compounding argument. Super currently returns an average of more than 7% after fees, while mortgage rates sit near 6.5% following this year's rate rises. Money sitting in an offset account earns nothing — it simply reduces the balance interest is calculated on — while the same dollar left inside superannuation keeps compounding. "Over time, placing your super in an offset means you would forgo more of an increase in your super balance than you save by reducing your mortgage. For most people, it would make them worse off over their lifetime," Eslake told realestate.com.au.

Matt Grudnoff, senior economist at The Australia Institute, broadly agrees, though he notes offset savings are tax-free while super earnings are taxed at a concessional 15%. Even accounting for that difference, he argues the dollar-for-dollar outcome still tends to favour leaving money in super. His fallback position is notable: if a borrower can't clear their mortgage by retirement, they can still take a super lump sum at that point and use part of it to pay down the remaining debt — preserving the compounding benefit for as long as possible.

There's also an unresolved structural question. It remains unclear under the Coalition's current proposal whether offset funds would need to stay locked to the loan. Eslake points out that once super sits in a standard offset account, "there's nothing to stop you taking it out and spending it on something else" — which raises questions about whether lenders could treat it as genuine collateral in the event of a default, or whether it functions more like a voluntary, revocable top-up.

APF analysis: the REIA case study assumes the full $172,000 remains parked against the loan for its duration. In practice, behavioural leakage — withdrawing some of that balance for other spending — would reduce the repayment savings while still carrying the full opportunity cost of lost super growth.

Context: Six Decades of Housing Affordability Schemes

Eslake's sharpest critique is historical rather than actuarial. He argues that every policy allowing Australians to spend more on housing — first homeowner grants, shared equity schemes, larger deposit caps — has pushed prices higher rather than improved affordability, citing "six decades of history, going back to the first homeowner's grant scheme in 1964." He treats a super offset scheme as functionally identical: if borrowers can service bigger loans using offset super, they will simply bid more for the same stock of housing, and prices adjust upward to absorb the extra borrowing capacity.

This argument connects to the long-running debate over whether Australia's house prices are structurally elevated relative to incomes — a question explored in more depth in APF's Does Australia Have a Property Bubble? guide. The choice between housing types also matters for how far any extra borrowing power stretches: APF's House vs Apartment in Australia analysis shows apartments offer a lower entry price but weaker long-run capital growth, which shapes who would actually benefit from offset access in each market segment.

Who Would Actually Benefit — and Who Wouldn't

The distributional case against the policy is arguably its weakest point for supporters. Association of Superannuation Funds of Australia figures cited in the report show the median super balance for 25-29 year-olds sits at around $21,000 for both men and women — an amount Eslake says "is not going to make much of a difference to how much you can afford to borrow." Balances rise modestly across older age groups, though the levels remain modest against current mortgage rates near 6.5%.

Eslake argues the real winners would be people who already have substantial super balances — a cohort "less likely to need help from the government in buying a home" in the first place. That inverts the policy's stated purpose of helping younger Australians locked out of the market while sitting on inaccessible retirement savings.

For borrowers currently weighing up loan structures regardless of what happens with super policy, the more immediate decision remains fixed versus variable rate selection and whether an existing offset or redraw facility is being used efficiently — questions covered in APF's Fixed vs Variable Rate Mortgage Australia 2026 comparison. First-home buyers assessing deposit size against lender requirements should also understand how LVR and LMI interact, since a larger effective deposit — whether from super or savings — directly affects lenders mortgage insurance costs.

The REIA's own modelling shows the offset mechanism can mechanically work — a $172,000 offset genuinely cuts a $519,000 mortgage's monthly repayment by a third. The unresolved question is whether that saving outweighs the compounding super growth given up, and whether widening access simply inflates the prices borrowers are trying to escape.

What This Means for Borrowers Right Now

No legislation currently allows super to be used as a mortgage offset. The Senate inquiry examined the concept, with Labor and the Greens expressing opposition to the approach. Borrowers should not factor this option into near-term refinancing or purchase decisions. Those under mortgage pressure from this year's rate rises have more immediate levers: reviewing offset account usage against standard redraw facilities, comparing fixed and variable terms, and checking whether current lender rates still reflect competitive market pricing given the broader run of rate increases referenced in the inquiry.

For prospective buyers with modest super balances — particularly those under 30 with balances near the $21,000 median cited by ASFA — the scheme, if ever legislated, would deliver limited practical benefit regardless of the final design. Those with larger balances should weigh Eslake's and Grudnoff's compounding arguments carefully before assuming an offset structure beats leaving super invested. Anyone exploring broader suburb-level buying decisions, including where borrowing power stretches furthest, can use APF's suburb research framework to separate affordability headlines from genuine value.