By Chaice Paterson, CEO & Founder, Low Deposit Homes | Updated June 2026

The single biggest objection Low Deposit Homes hears from first home buyers in 2026: “what if interest rates go up after I buy?” The honest answer in three parts: first, banks already stress-test your loan at rates 3% higher than today’s — so you’ve been approved on the assumption that rates can rise meaningfully without breaking your serviceability. Second, the Reserve Bank’s cycle of rate movements means today’s rates are unlikely to be tomorrow’s rates either way (up or down). Third, the much bigger long-term risk for most first home buyers isn’t a future rate rise — it’s the opportunity cost of not buying at all and continuing to pay rent that builds someone else’s equity. This guide gives the real numbers behind rate risk for first home buyers and the practical defences you can build into your structure.

The Bank Already Tested You at Rates 3% Higher Than Today

This is the single most important fact that most first home buyers don’t know.

When the bank assesses your loan, they don’t use today’s variable rate (around 6%). They use what’s called the serviceability buffer rate — the actual interest rate PLUS 3%. So if your loan is at 6%, the bank assessed your capacity to make repayments at 9%.

What this means in practice:

• Your loan was approved on the assumption you can handle a 3% rate rise
• A 1% rate rise consumes about a third of the buffer you’ve already been approved against
• A 2% rate rise consumes about two thirds of the buffer
• Only above 3% does the rate rise exceed the buffer the bank already tested for

In dollar terms, on a $950K loan (typical 5% Deposit Scheme structure on a $1M property):

A 2% rate rise — significant by historical standards — adds approximately $560/month to your repayments. Real, but within the buffer the bank already tested.

The Real Risk Most Buyers Don’t See: Rent

Here’s the comparison that doesn’t get made enough.

Imagine you don’t buy. You continue renting at $620/week in Pakenham, or $580/week in Tarneit, or $620/week in Caboolture. Over 30 years at modest rental inflation of 3% annually, you’ll pay approximately:

• $620/week starting → $1,506/week by year 30 → $1.74 million total rent paid
• $580/week starting → $1,409/week by year 30 → $1.63 million total rent paid
• $620/week starting → $1,506/week by year 30 → $1.74 million total rent paid

You’ll have paid roughly $1.6M to $1.75M in rent. You’ll own nothing.

Compare to buying a $1M new build today at 6%. Even if rates average 7% over the loan’s life (significantly above today), you’ll pay approximately $1.55M in mortgage payments over 30 years. You’ll own a property worth (at conservative 3% annual growth) approximately $2.4M.

The renting “savings” of having no mortgage are an illusion. Rent doesn’t stop. Mortgage payments eventually do.

“Every first home buyer I speak to worries about rates going up. Almost none of them worry about rent going up. Rent has gone up 6%+ per year in most of our corridors over the past three years. Mortgages on fixed-price contracts don’t have that problem — your repayment is set by the rate, and the principal stays the same regardless of what’s happening in the property market. The real interest rate question isn’t ‘what if rates rise’ — it’s ‘what if rents keep rising while I wait for rates to fall.'” — Chaice Paterson, founder of Low Deposit Homes

Practical Defences You Can Build Into Your Loan Structure

Three practical levers reduce your exposure to rate rises:

1. Offset Account

An offset account is a transaction account linked to your home loan. Every dollar sitting in the offset reduces the loan balance the bank charges you interest on.

A first home buyer with $20,000 in their offset on a $950K loan saves approximately $1,200/year in interest at current rates — more if rates rise. Over the life of the loan, that $20K saved consistently in offset can shave 4–6 years off a 30-year mortgage.

Most LDH clients structure their loan with an offset from day one and use it as their primary savings/transaction account.

2. Fixed-Rate Component

Splitting your loan into a fixed portion and a variable portion protects against rate rises on the fixed portion. The trade-off: fixed rates are typically slightly higher than variable at the time of fixing, and break costs apply if you sell or refinance during the fixed period.

A common structure: 50% fixed for 2–3 years (rate protection) + 50% variable (offset flexibility). The right split depends on your view of rates and your need for flexibility.

3. Buffer Savings Held In Offset

Maintaining $5K–$10K in your offset account (not a separate savings account) dedicated to mortgage buffer means you absorb a rate rise without immediate cash flow stress, AND those funds continue offsetting the loan and reducing the interest you’re charged. It’s the most efficient way to hold a buffer — your safety net does double duty as ongoing interest savings.

Why Large Rate Rises Are Historically Slow

A specific point worth understanding about how the RBA moves rates: the standard increment for an RBA rate decision is 25 basis points (0.25%) per meeting. The RBA meets eight times per year. So the maximum theoretical rate rise over 12 months is 2% (eight 0.25% increases in a row) — but that’s never happened in modern history.

Historically:

• 2022–2023 tightening cycle: 4.25% increase over 18 months — the most aggressive cycle in three decades
• Most other cycles: 0.5–1.5% total movement over 12–18 months
• Cuts and holds occur as the economy responds

Practically, a “rate shock” that genuinely breaks serviceability is a slow-moving event — typically 12–18 months of gradual increases with the RBA pausing along the way. This gives you time to adjust, refinance, or restructure long before any forced action is necessary. The conversation about “what if rates rise 3%” is real, but it’s a 12–18 month conversation, not a next-quarter conversation.

What Happens If Rates Actually Do Rise Significantly?

A worst-case scenario worth thinking through. If rates went from current 6% to 8.5% over 2 years:

Your options:

• Reduce other discretionary spending. Most households can find $300–$500/month in flexibility without major lifestyle change.
• Extend the loan term. If you have a 30-year loan with 25 years remaining, switching back to a 30-year term reduces monthly repayments by 10–15%.
• Refinance to a different lender. Other lenders may offer better rates during high-rate environments.
• Use offset to reduce interest. Aggressive use of offset (parking extra cash in offset) reduces the loan balance interest is charged on.
• Sell. The worst-case option. The property has likely appreciated in value, so even a forced sale typically delivers equity. New build first home buyers who buy in growth corridors and hold 5+ years almost always exit with equity.

Importantly, the bank has multiple options before any of these become urgent. Lenders generally work with borrowers experiencing rate-rise stress — payment deferrals, hardship arrangements, and refinancing pathways exist.

What About Buying Now vs Waiting for Rates to Drop?

A specific question that comes up often: “shouldn’t I wait for rates to drop before I buy?”

Two considerations:

1. Property prices typically rise when rates fall. When the RBA cuts rates, borrowing capacity increases across the market, which drives property prices up. Waiting for a rate cut often means buying a similar property at $50K–$100K higher than today. The “saving” on the interest rate is consumed by the higher purchase price.
2. You’re paying rent during the wait. Every month you delay, you pay rent that builds someone else’s equity. At $600/week rent, 12 months of waiting costs $31,200 in unrecoverable rent. That’s roughly equivalent to the entire VIC FHB stamp duty saving on a $750K new build.

The historic pattern: buyers who waited for “perfect timing” consistently bought later at higher prices. Buyers who bought when they were ready — based on their own circumstances, not the rate cycle — built more wealth over time.

Frequently Asked Questions

What happens to my mortgage if interest rates go up 2% after I buy?

On a $950K loan (typical 5% Deposit Scheme structure on a $1M property), a 2% rate rise increases weekly repayments by approximately $280 — from around $1,260/week to around $1,540/week. Significant, but within the 3% serviceability buffer the bank already approved you against. Practical defences include using an offset account, maintaining buffer savings, or splitting part of the loan to a fixed rate.

Should I wait for interest rates to drop before buying my first home?

Generally no. When rates drop, property prices typically rise as borrowing capacity increases across the market. Waiting for rate cuts often means buying a similar property at $50K–$100K higher than today, plus paying $25K–$35K in additional rent during the wait. The right time to buy is when YOUR circumstances are ready — sufficient deposit, stable income, scheme structure understood — not when the market is at a particular point.

What’s a good interest rate buffer to plan for?

Banks currently use a 3% buffer for serviceability assessment. As a first home buyer, planning your household budget to comfortably support a 2% rate rise gives you meaningful safety margin. A typical structure: save 10–15% of your monthly mortgage payment as a buffer reserve in an offset account, and avoid maxing out your borrowing capacity at the time of purchase.

Does the 5% Deposit Scheme protect me if rates rise?

The 5% Deposit Scheme doesn’t directly protect against rate rises — your loan remains subject to whatever rate your lender charges. However, the scheme’s no-LMI structure means more of your savings stay in your offset account or pocket, which provides indirect rate protection. The bank still uses the full 3% buffer when assessing your serviceability under the scheme.

What if I can’t make my mortgage payments because of rate rises?

Multiple options exist before things become critical. Lenders are required to work with borrowers experiencing financial hardship — payment deferrals, longer loan terms, refinancing assistance, and other arrangements are all available. The earliest sign of stress, contact your lender (or your broker). Falling behind silently is the worst path; engaging early almost always preserves options.

Ready to See How Your Structure Holds Up Under Rate Movements?

Book a free 15-minute consultation with Low Deposit Homes — Book your free call | Call 1800 920 172

We’ve helped 1000+ families through multiple rate cycles. The consultation is free, and we’ll model your specific situation across different rate scenarios so you understand exactly what you’re committing to.

Low Deposit Homes operates under Winning Homes Australia Pty Ltd (ACN 633 321 758). All deposit calculations are indicative and based on general scenarios. Individual circumstances may vary. Government grant eligibility is subject to assessment by the relevant authority. This guide is for informational purposes and does not constitute financial advice.