You're looking to buy a property and you find two units you really like. Both were advertised as 1,000 sqft, but when you viewed the properties in person, you noticed that one felt considerably smaller than the other.

Huh? That's weird.

These two units look identical on paper. How can they feel completely different in real life?

Maybe it's just your imagination. Or maybe, it's harmonisation.

For decades, Singapore's property market had a measurement problem, and most buyers had no idea it even existed. Because it wasn't standardised, different government agencies were measuring floor area differently.

The Urban Redevelopment Authority (URA) measured Gross Floor Area (GFA) by including the thickness of the external walls, but excluded void spaces.

The Singapore Land Authority (SLA) measured strata area only up to the middle of the wall and may include voids.

The Building and Construction Authority (BCA) applied its own Statistical Gross Floor Area (SGFA) definition, with different inclusions and exclusions depending on the purpose of measurement.

The Singapore Civil Defence Force (SCDF) measures Accessible Floor Area (AFA) by excluding the thickness of the external walls.

Source: URA

As a result, the same physical space could have different "official" sizes depending on which agency was doing the counting.

But aside from being a bureaucratic headache for architects and engineers, this issue also had very real consequences for buyers. Because of the inconsistencies between how agencies measured floor area, developers found legitimate ways to include spaces in a unit's advertised size that weren't actually liveable.

Two of the most common examples:

First, air-conditioning ledges. That narrow concrete ledge outside your window where the aircon compressor sits? Before harmonisation, it was typically counted as part of a unit's strata area, a space you legally own and paid for. Industry figures suggest AC ledges typically accounted for around 4-5% of a unit's total saleable area. Not enormous, but not nothing either.

Second, strata voids. Picture a unit with an impressively high ceiling. Double-volume, dramatic, the kind that makes the living room feel like a palace. In older developments, that empty vertical space (the "air" above your head) was sometimes included in the unit's strata area. So a unit with 800 sqft of actual floor might be advertised as 1,000 sqft once the void was factored in. The psf looked more attractive on paper, but you were actually paying more for space you couldn't even walk on.

So, back to those two 1,000 sqft units that felt so different. Now you know why.

In September 2022, URA announced that floor area would be defined and measured the same way across all agencies. One rule for everyone. In other words: harmonised.

The new rules apply to development applications submitted to URA on or after 1 June 2023, and GLS sites launched for sale from 1 September 2022. This means not every new launch marketed after June 2023 is necessarily GFA-harmonised. It depends on when the development application was filed.

The key changes were:

• All agencies now measure floor area to the middle of the external wall, not the outside edge, not varying interpretations.
• All strata areas are now counted as GFA. This closed the loophole that allowed spaces like oversized air-con ledges to exist in a grey zone between "owned" and "counted."
• Strata voids are excluded from both strata area and GFA. No more paying for empty air.

Basically, if a space is legally owned by a unit (for example, it forms part of the strata area), it must be counted as GFA. If it is not owned, or if it doesn't have a floor you can stand on, it should not inflate the unit size.

There are more details pertaining to how GFA is now measured. If you'd like to know more, URA has it all laid out for you here: GFA clarification and revised GFA definition.

For one thing, newer units may look smaller on paper. But they're not.

A unit that might have been marketed as 1,000 sqft under the old rules could be listed as 950 sqft today. Not because it's actually smaller, but because non-liveable spaces like void ceilings and aircon ledges are no longer counted in the floor area.

This matters a lot when you're comparing a new launch against a resale unit built before 2023. The resale unit may appear to offer more space for the money. Sometimes that's true. Sometimes it's just the old measurement rules.

Additionally, psf prices look higher. But so is the value of newer homes.

As the advertised floor area of new units decreased (because inflated spaces were stripped out), it's only natural that the psf went up.

Initially, this caused some shock, but if you think about it, the total quantum (the actual amount you pay) hasn't changed dramatically. Here's a real-life example.

Transaction data from PropNex Investment Suite

This 2-bedroom unit at Hillock Green was sold as 775 sqft at $1,882 psf, making the total price $1,458,200. However, the AC ledge and empty void took up 189 sqft, so the livable space was only 586 sqft. If the quantum was based on the livable area, the psf would be $2,488 instead.

Meanwhile, a similar unit at Lentor Mansion was sold as 657 sqft, with the quantum totaling at $1,539,000. At first glance, it may seem more expensive. But if we look at the psf, it's actually cheaper (based on livable space) at just $2,344.

By the way, both units are located around the same area and also on the 13th floor.

Image taken from Google Maps

The takeaway here is: relying solely on price psf to compare units built under different measurement regimes can lead you to the wrong conclusion. So...

If you're buying a new launch: Understand that the psf of a post-harmonisation new launch will, by design, look higher than a comparable resale unit. But that headline number alone tells you very little about which is the better investment. What matters is whether the usable space justifies the price, how efficiently the unit is designed, and whether the overall quantum makes sense relative to rental yield or resale potential.

If you're buying resale: Check whether the listed floor area includes void spaces, large ledges, or other features that would not be counted in a post-harmonisation development. These can be genuine perks or they can flatter the numbers. Know the difference.

Pro tip: look at whether the AC ledge is listed as 'Non-Strata' in the floor plan. If it is, the unit is GFA-harmonised.

If you own a pre-harmonisation property and are thinking of selling, it creates an interesting dynamic in your favour, though you should still be careful in your positioning.

Your unit likely has features that newer developments simply don't build anymore like high ceilings, a private rooftop terrace, or generous ledges that were counted in the original strata area. These features make your property look "larger" on paper compared to new launches.

Some buyers will recognise this as a feature, not a bug. A high-ceiling unit in a resale condo, even if the void isn't strictly liveable, can create a sense of space and luxury that many buyers will pay a premium for. Older properties with large layouts that would not be replicated under modern GFA rules have, in some cases, seen renewed interest in the resale market precisely because of this distinction.

The key for sellers is transparency. With buyers becoming more educated about harmonisation, presenting your property's floor area accurately, and explaining the difference between older and newer measurement standards, builds trust and avoids disputes down the line.

GFA harmonisation is, at its core, a transparency reform and standardisation of floor area measurement. It's the government's way of making the market fairer and uniform so every buyer can know exactly what they're paying for.

It makes things simpler. Here is the space, here is the price. Make an informed decision.

A bigger square footage doesn't automatically mean better value. And a higher psf doesn't automatically mean more expensive. It's more important to be able to interpret how much of that space is actually usable and whether or not the overall price makes sense for what you're getting.

If you want to learn how to read the market beyond just the numbers, that's exactly what we cover in our Property Wealth System (PWS) Masterclass. Here's a short clip to get you started.

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