At a R1.5 million purchase price with a 10% deposit and a 9% mortgage rate over 20 years, expect a monthly bond repayment of roughly R12,150. That single line — price, deposit, rate, term — contains the three levers that decide whether a house fits your budget.
By the end of this article you will understand what lenders actually measure, how much salary different homes require, and the hidden costs that turn an affordable purchase into a financial squeeze. You will leave with clear numbers you can compare to your payslip and your savings.
Banks are not trying to be mean. Their affordability tests exist to ensure you can make payments for 20 or 25 years without defaulting. The routine checklist includes your gross income, proven employment history, existing debt repayments, monthly living expenses, and your credit record. Lenders also look at the size of your deposit and the property itself — a home with informal structures, for example, can be harder to bond.
Two rules of thumb matter more than marketing claims. First, lenders commonly expect the mortgage repayment to be no more than about 27–30% of your gross monthly income. Second, total debt commitments — bond plus car finance, credit cards, personal loans — usually must sit comfortably under roughly 40–45% of gross income. These are rules of thumb; individual banks and bond assessors will vary the tolerances, but they set an immediately useful test: take your expected monthly bond payment, divide it by your gross pay, and see where you land.
Credit behaviour determines access. If you have missed payments, judgment orders, or unauthorised overdrafts, lenders will either charge a higher rate or refuse a bond. The National Credit Regulator enforces rules around reckless lending and credit records, and banks will insist on several months of bank statements and payslips to verify what your monthly life really looks like. For official guidance on credit checks see the National Credit Regulator.
Numbers remove wishful thinking. Below are three realistic purchase prices and the simple arithmetic that converts a house price into a monthly obligation and the income likely needed to carry it. I use a 20-year loan term and a 9% interest rate as a baseline; change the rate or term and the payments shift fast.
Scenario A — Starter home: Purchase price R700,000. With a 10% deposit (R70,000) the loan is R630,000. At 9% over 20 years the monthly bond payment is about R5,670. Using the 27% mortgage-rule, that payment requires gross monthly earnings of roughly R21,000 (about R252,000 a year).
Scenario B — Mid-range: Purchase price R1,500,000. A 10% deposit is R150,000, so the loan is R1,350,000. The monthly payment at 9% for 20 years is about R12,150. To keep that payment near 27% of income you would need gross monthly earnings of about R45,000 (R540,000 a year).
Scenario C — Family upgrade: Purchase price R3,000,000. With 10% deposit the loan is R2,700,000. At 9% over 20 years expect roughly R24,300 per month. That implies gross monthly earnings around R90,000 to make the bond repayment near 27% of income.
These are working examples, not bank quotes. Lengthening the term to 25 years reduces monthly cost but increases total interest paid; lowering the interest rate by even one percentage point reduces monthly payments materially. For up-to-date policy rates consult the South African Reserve Bank and then run the numbers through a bond calculator.
As a practical filter, if your expected bond payment consumes more than 30% of gross income, you should either increase the deposit, choose a less expensive property, or extend the term.
Price is only the headline. The transaction and running costs that follow a purchase often catch first-time buyers off guard. Upfront you must cover the deposit plus transfer duty (when applicable), conveyancer and bond registration fees, municipal clearance certificates, and moving costs. A conservative rule is to budget around 6–8% of the purchase price for transaction-related expenses if transfer duty is payable; first-time buyers or those using a government subsidy may pay less.
Ongoing costs are equally important. Monthly municipal rates and taxes, electricity, water, refuse, homeowners association levies (if you buy in a complex), insurance, and maintenance can add thousands to your monthly budget. For example, a property with a monthly levy of R1,800 plus R2,000 for rates and taxes and R1,200 for insurance and reserves pushes required disposable income up by R5,000 every month. Treat those numbers as recurring fixed costs when assessing affordability.
Insurance is non-negotiable. Lenders will require home and life insurance or credit life cover — the latter to settle the bond in the event of death or permanent disability. That cost varies with age and health, but budget R400–R1,200 per month depending on the cover levels and the size of the bond.
You can’t change interest rates, but you can change the things a lender cares about. The fastest lever is savings. Increasing your deposit from 10% to 20% drops the loan amount and monthly payment sharply and may get you a better rate. Where possible, clear smaller unsecured debts before applying for a bond: removing a R3,000 credit-card repayment from your monthly commitments immediately reduces the debt-to-income ratio and increases affordability.
Joint applications work. A second income, whether from a spouse or a parent co-signer, multiplies purchasing power without changing the interest rate. That said, lenders consider all incomes and all debts of both applicants, and every applicant becomes jointly responsible for the bond. The practical benefit is clear: two moderate salaries often support a property one income could not.
Stretching the term will lower monthly payments. Extending from 20 to 25 years can reduce monthly outlay by roughly 15–20% depending on the rate, but it increases the interest paid over the life of the loan. Choose a longer term only if you have a plan to increase payments later or want breathing room for other financial goals.
Improve the parameters banks look at. A clean credit record, three to six months of stable bank statements showing consistent saving behaviour, and formal payslips make lenders more comfortable and can mean access to slightly better pricing. Also, shop around. Different banks and bond originators price risk differently; the cost of moving between prime minus and prime plus margins can be tens of thousands over the life of the bond.
Take out a payslip, your latest bank statement, and your savings total. Do the simple math: what deposit can you afford today? What monthly payment would your household tolerate without cutting essentials? Multiply that tolerable payment by about 3.7 to estimate the gross monthly income a bank will want to see if you follow the 27% rule. For example, if you can comfortably pay R10,000 per month towards a bond, a lender will look for gross monthly income near R37,000.
Two common mistakes weaken otherwise sound plans. The first is ignoring municipal rates and levies; factor them into the monthly cost from the outset. The second is assuming advertised interest rates are the final price; the advertised rate may exclude particular credit penalties or fees, and your personal margin will depend on the bank’s view of your risk.
Decide what you will not sacrifice. If you value being debt-free in retirement, avoid 30-year terms. If location matters more than size, prioritise a deposit that leaves you a buffer for monthly operating costs. Whatever you choose, align the mortgage term, deposit and realistic monthly budget so the house supports your life, rather than your life shrinking to support the house.
Buying a home in South Africa is a series of trade-offs, not a single calculation. The clean takeaway is simple: know the monthly payment a property generates, measure that payment against gross income and other debt, and add the transaction and running costs to your monthly budget. Do those three things and you will know, with useful precision, how much house you can afford.
