Income Weighted Average Age (IWAA)

5 min read

Every day, takes a piece of property jargon and demystifies it. Today, we’re looking at the Income Weighted Average Age (IWAA):

Before we get into it, you need to know about the LTV

For the IWAA to make sense to you, you first need to understand the concept of the LTV. As a quick summary, the LTV ratio determines how much money you can borrow to buy your house. An LTV of 80%, for example, means that you can borrow up to 80% cent of the price or value of your house (whichever is lower).

The LTV ratio is affected by a number of factors. One of these is your age, and the loan tenure:

  • For a loan tenure exceeding 30 years (the maximum is 35 years), your LTV will drop to 55%.
  • If your age plus the loan tenure exceeds the retirement age of 65, your LTV will also drop to 55%.
Money bags on a weighing scale with a house
Do you know what an LTV is? That’ll help with understanding the IWAA.

This can result in a massive cash outlay. For example:

Say you’re buying a condo at S$1.5 million (assume the valuation matches the price). Under normal circumstances, you would be looking at a downpayment of at least S$300,000.

But say your loan tenure is 30 years, and your current age is 40. Your age plus your loan tenure (40 + 30) takes you beyond the retirement age of 65. As a result, your minimum down payment becomes a stunning S$675,000.

This is where many people get a co-borrower, and IWAA matters

It’s quite common for a property to have more than one buyer / borrower. In this case, the bank still needs to calculate the LTV limit; but what if both borrowers have different ages?

Group of people raising hands
It’s quite common for a property to have more than one buyer / borrower.

When that happens, the bank will use the IWAA. The formula is as follows:

IWAA = (Monthly income of borrower A x age of borrower A) + (Monthly income of Borrower B x age of Borrower B) / total monthly income of borrowers

For example:

Say you are 40 years old, with an income of S$4,500 per month.

Your spouse, who is your co-borrower, is 33 years old. She has an income of S$6,000 per month.

IWAA = (S$4,500 x 40) + (S$6,000 x 33) / S$4,500 + S$6,000 = 36

In this scenario, your age will count as being 36.

To qualify for the maximum LTV of 80%, your maximum loan tenure must be 29 years (29+36 = 65).

The general rule to remember

If all the numbers are annoying you, just bear this in mind:

When the younger borrower earns more, the IWAA will be lower. When the older borrower earns more, the IWAA will be higher.

Millennial thinking about renting an apartment
When the younger borrower earns more, the IWAA will be lower.

Sometimes, you have to be strategic about this to get the maximum loan quantum. For example, say your spouse is younger than you, but earns less than you. Your son, however, earns more than you. If you want your IWAA to be lower, consider having your son as the co-borrower instead of your spouse.

The IWAA can cause your loan repayments to jump significantly, if you got your loan before it was in effect

If you got your home loan before June 2013, the IWAA was not yet in effect. However, if you refinance your home loan now, it will be – and this can cause your monthly repayments to jump to stunning heights.

For example, let’s say you took your home loan back in 2010. At the time, you were 36 years old, and earning S$7,000 a month. Your spouse was 30 years old, and earning S$4,000 a month. You used your spouse’s age to get the loan, as there was no IWAA at the time; this would allow you to get the maximum LTV.

Girl checks her credit card
If you refinance your home loan now, the IWAA will be in effect.

Let’s say you took a 30 year loan tenure with an 80% LTV (possible at the time). At 2% interest, that comes to S$3,696 per month.

Today however, you spot a loan with a rate of just 1.7%. You decide to refinance.

This time however, the IWAA kicks in. Assuming your incomes have not changed, your IWAA is:

(S$7,000 x 46) + (S$4,000 x 40) / S$11,000 = 43

To maintain the maximum LTV, your age plus the remaining loan tenure cannot exceed 65. As such, your maximum loan tenure is shortened to 22 years.

Even at a reduced interest rate of 1.8%, your monthly repayment will become S$4,590 per month; almost S$894 more.

So if you got your home loan before June 2013, be careful to crunch the numbers first.

Before you agree to pay for a valuation, start paying down debts to improve your TDSR and so forth, get the numbers from the bank. The higher repayments can create quite the dent in your cash flow, if you’re not paying home loans through your CPF.

What bit of jargon confused you? Let us know in the comments section below.

Looking to sell your property?

Whether your HDB apartment is reaching the end of its Minimum Occupation Period (MOP) or your condo has crossed its Seller Stamp Duty (SSD) window, it is always good to know how much you can potentially gain if you were to list and sell your property. Not only that, you’ll also need to know whether your gains would allow you to right-size to the dream home in the neighbourhood you and your family have been eyeing.

One easy way is to send us a request for a credible and trusted property consultant to reach out to you.

Alternatively, you can jump onto’s Property Value Tool to get an estimate for free.

If you’re looking for your dream home, be it as a first-time or seasoned homebuyer or seller – say, to upgrade or right-size – you will find it on Singapore’s fastest-growing property portal

Meanwhile, if you have an interesting property-related story to share with us, drop us a message here — and we’ll review it and get back to you.

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