Over fifteen years, URA rewrote what counts as floor area in a Singapore condo, bay windows, balconies, AC ledges, voids. Each change reshaped the layouts and unit sizes on sale today. Here's the timeline, and how to read an old floor plan because of it.
TL;DR
Two condos can list the same square footage and the same price per square foot, and one of them is a much better home than the other. The difference is usually not the developer's taste. It's the year the project was approved, and which URA rules were in force when the architect drew it. Over roughly fifteen years, the Urban Redevelopment Authority rewrote what counts as floor area in a Singapore condo, and each change fed straight into the layouts, unit sizes and prices on sale today.
This is the long version: every circular that matters, in order, with the reason URA gave for it, what it did to the floor plan, and what it means when you compare two units. Keep one fact in your pocket as you read, the rule that drew a unit is the rule in force when the development's plans were approved, not when it was sold or when you're buying it. A 2008-approved project that only launched in 2011 was drawn under the old rules.
Sources: URA development-control circulars (cited by number in each section below) and the joint URA/SLA/BCA/SCDF floor-area harmonisation circular. As at June 2026.
A condo developer buys land with a fixed budget of Gross Floor Area (GFA), the plot ratio times the site area sets a hard ceiling on how much floor the project can have. Every square metre of GFA is paid for in the land price. So the developer's standing incentive is to find space they can sell to you that doesn't count against their GFA budget: space that is free to them but billed to you at full price per square foot.
For years, URA's own rules created those free spaces: bay windows, planter boxes, generous balconies, air-con ledges, private enclosed spaces, even airspace voids. Developers built as many of them as the rules allowed, because each one inflated the strata area, what you legally buy and pay PSF for, without consuming the GFA they paid the government for. The history below is URA closing these gaps one at a time, leaving condos with cleaner layouts and listed sizes that track the space you can actually use.
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To read any of this, you need to keep two numbers apart.
For most of Singapore's condo history these two were calculated on different bases. Before June 2023, URA measured GFA to the full thickness of the external walls and excluded voids; SLA measured strata area only to the middle of the wall and could include voids (URA circular DC22-09, Appendix 1, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc22-09). Two different numbers described the same unit. More importantly, certain spaces could sit inside your strata area, so you paid for them, while sitting outside the developer's GFA budget, so they cost the developer nothing. That gap is the entire reason features like bay windows, planter boxes and AC ledges were worth building: they were strata area the developer got for free and sold to you at full price. Most of the timeline below is URA, and eventually four agencies together, narrowing and finally closing that gap.
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Select a column heading to sort.
| ~2001 | 2001 Balcony Incentive Scheme | Balconies (later PES and roof terraces too) granted as bonus floor area on top of the plot-ratio ceiling, up to about 10% | The start of the big-balcony era, outdoor space the developer got cheaply and sold at full price |
| 1 Jan 2009 | DC08-17 / DC08-18, bay windows and planter boxes | Both stopped being exempt from the GFA budget | The biggest single layout cleanup; bay-window ledges and planter troughs largely disappear |
| 29 Jul 2009 | DC09-03, bonus-GFA framework | Every bonus-GFA scheme put under one shared cap of 10% above the Master Plan limit | One combined bonus budget; no stacking of incentives |
| 12 Jan 2013 | DC13-01, PES and roof terraces | Private enclosed spaces and roof terraces folded into that same 10% bonus pool | Ground-floor patios stop being unlimited "free" area |
| Nov 2013 / Dec 2014 | DC13-10 / DC14-27, balcony bonus tied to build quality | Balcony bonus made conditional on prefabrication and buildability scores | Pushed the industry toward precast construction |
| 12 Jun 2014 → 9 Nov 2020 | DC14-16, LUSH 2.0 communal-planter bonus | Wider communal planters could earn a GFA exemption on design merit; window has since closed | A short-lived greenery incentive; expired, so the 1 m cap is back |
| 17 Jan 2019 | DC18-06, minimum average unit size + unit mix | Outside the Central Area, the unit-count cap rose so the average unit must be at least 85 sqm (was 70 sqm); 100 sqm in nine estates; plus a 20%/20% unit-mix rule | Fewer, larger units on average; studios still allowed, but offset by bigger units |
| 17 Jan 2019 | DC18-07, balcony bonus cut | Balcony bonus reduced from 10% to 7%; per-unit balcony capped at 15% of net internal area; "no-balcony option" and disclosure required | Smaller, fewer, better-controlled balconies |
| 5 Jul 2019 | DC19-11, GFA refinements | Tidied up how sky terraces, balconies and M&E spaces are measured | Procedural; little direct buyer impact |
| 2020 | DC20-07, the GFA Handbook | Consolidated every GFA rule into one live online reference | The single place to look up any element's treatment |
| 18 Jan 2023 | DC22-10, Central-Area unit-size floor | In 11 Central-Area planning zones, at least 20% of units must have a net internal area of 70 sqm or larger | At least one in five units must be family-sized, even downtown |
| 1 Jun 2023 | DC22-09, floor-area harmonisation (URA/SLA/BCA/SCDF) | Four agencies aligned their floor-area definitions to a common, mid-wall basis; strata AC ledges now count; voids excluded from strata area | Newer units' listed sizes are smaller on paper but closer to usable space |
The bold rows reshaped layouts the most. Here is each rule in turn.
A URA scheme introduced in 2001, the Balcony Incentive Scheme (BIS), gave developers bonus GFA, extra buildable floor above the plot-ratio ceiling, for balconies, and over time for private enclosed spaces (PES) and roof terraces, up to about 10% of the site's GFA. The intent was to encourage breezy, outdoor-connected homes and high-rise greenery. The effect was that balconies became a developer's favourite square footage: floor they got granted cheaply and sold at full PSF. It is why condos from the 2000s and 2010s so often carry large, sometimes oversized, balconies.
The scheme went through four distinct phases over the next two decades: the 2001 launch (PES and roof terraces fully GFA-exempt at the time); revised balcony guidelines in 2007; the bringing of PES and roof terraces into the bonus pool in 2013; and the tightening in 2019 that cut the cap and added per-unit limits. Each phase is covered below.
The scheme dates to 2001, URA's later circular DC18-07 records that the Balcony Incentive Scheme was "introduced in 2001" (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc18-07), and the ~10% bonus is set out in URA's Bonus GFA guidelines. The 2001 scheme predates a published circular number. A revised set of balcony guidelines followed in 2007 (URA circular reference URA/PB/2007/01-DCD), which later versions built on.
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This is the change that most cleanly splits "old" condos from "newer" ones. Before 2009, bay windows, the raised ledges projecting from bedroom and living-room walls, and in-unit planter boxes, the sunken troughs outside windows and balconies, were excluded from GFA entirely. They cost the developer nothing in land, but were sold to you inside the strata area at full price.
Why bay windows were exempt in the first place. URA originally treated a bay window as a raised window ledge sitting above the floor slab, an architectural feature, not usable living space (URA circular DC08-17, background, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc08-17). On that logic it sat outside the floor-area count. The problem was that, year by year, the allowed ledge height was relaxed, eventually to as little as 0.5 m above the floor. At that point the "ledge" was functionally indistinguishable from ordinary floor: you could sit on it, place furniture against it, or turn it into a study nook. The distinction that had justified the exemption had quietly disappeared (DC08-17).
URA's three stated reasons for removing it. URA gave notice in a July 2008 circular, DC08-17, and set out three problems with the exemption: bay windows were adding significantly to overall building bulk; they were affecting building design in undesirable ways; and they did not encourage energy efficiency. URA's conclusion was blunt, the exemption had "unwittingly shifted market behaviours and negated the objective of the GFA exemptions for these building features" (DC08-17). In other words, a rule meant to encourage a nice architectural touch had instead become a tool to sell more floor area.
The grace period and the real start date. DC08-17 originally set the change to take effect on 7 October 2008, a three-month grace period from publication. Industry fed back that many projects were at an advanced design stage under the old rules and would have to rush submissions. URA agreed and issued a follow-up circular, DC08-18 (published 22 September 2008), pushing the effective date to 1 January 2009 (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc08-18). That is the operative date: projects whose plans were approved before 1 January 2009 keep the old treatment; everything submitted from 1 January 2009 onward counts bay windows as GFA.
The change was broader than condos. The removal applied to bay windows in all development types, residential, commercial, hotel, business parks, not just private homes. The old exemption had been most heavily exploited in residential units, where the extra ledge area was sold to buyers as internal space (DC08-17, title and para 2).
Developers could still build them, they just had to pay. URA explicitly said it would "leave it to the developers and building owners to decide if they wish to continue to provide bay windows" (DC08-17, para 8). The catch: from 2009 every square metre of bay window ate into the site's GFA budget, the same as any other floor. Because that space now competed directly with other saleable area, developers had a strong commercial reason to drop them, which is why the bay-window nook largely vanished from new condo floor plans after 2009. URA also noted there would "no longer be restrictions on the size of bay windows," since the dimension caps that had been a condition of the old exemption no longer had anything to attach to.
Why it matters to you. A pre-2009 unit's listed size includes bay-window ledges and planter troughs you cannot furnish or count as real living space, sold at the same PSF as the living room. In one example cited in property commentary at the time, bay windows and planter boxes together added up to close to a quarter of one small unit's floor area. After 1 January 2009, every such square metre costs the developer real GFA, so they largely vanished. Post-2009 floor plans have flush walls and cleaner balcony edges, and the strata area you buy tracks much closer to liveable floor. URA still maintains a live GFA Handbook page on bay windows confirming the standing position since 1 January 2009 (https://www.ura.gov.sg/Corporate/Guidelines/Development-Control/gross-floor-area/GFA/BayWindows).
Sources: URA circular DC08-17 (July 2008, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc08-17) and the follow-up DC08-18 (published 22 September 2008, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc08-18), which fixed the 1 January 2009 start date after feedback. Industry estimates at the time suggested developers stacking bay windows, planter boxes, PES and roof terraces could push a unit's effective saleable area to 115–125% of the GFA they were allocated, that figure is industry commentary, not a URA number. The ~quarter-of-a-unit figure is one illustrative single-unit example from 2009 property commentary, not a URA figure.
The same two 2008 circulars also removed the GFA exemption for planter boxes within a residential unit, on the same 1 January 2009 date. Before that, in-unit planters were fully GFA-free, and URA's own circular records that developers had steadily enlarged them "beyond what would be considered adequate for planting," effectively selling extra floor area outside GFA controls (DC08-17). One narrow exception was preserved: a planter box that sits within a balcony can be treated as part of the balcony's own bonus-GFA envelope.
Not every planter lost its exemption, though. Planter boxes in communal areas (sky terraces, common corridors) and in non-residential developments kept their GFA exemption, because URA judged those to be genuinely planted and well-maintained by the MCST. The carve-out is strict and binary: to stay GFA-free today a communal planter must be no wider than 1.0 m (measured from the façade), have a minimum depth of 500 mm for planting, and be sufficiently externalised, not hidden behind full-height screening. Fail any one of those and the entire planter counts as GFA (URA GFA Handbook, Planter Boxes, last updated 26 July 2023, https://www.ura.gov.sg/Corporate/Guidelines/Development-Control/gross-floor-area/GFA/PlanterBoxes).
For a brief window, wider communal planters could earn more. Under the LUSH 2.0 Programme, circular DC14-16 (effective 12 June 2014) let communal planters wider than 1 m qualify for a GFA exemption if they formed part of an integrated landscape scheme, judged case by case on design merit (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc14-16). That bonus window closed on 9 November 2020; the standard 1 m cap now applies again.
Sources: URA circulars DC08-17 and DC08-18 (planter boxes within residential units, effective 1 January 2009); URA GFA Handbook, Planter Boxes; URA circular DC14-16 (LUSH 2.0, effective 12 June 2014, expired 9 November 2020).
Right after the cleanup, URA's DC09-03, the "Framework for Managing Bonus GFA Incentives," published 29 April 2009 with the cap taking effect 29 July 2009, put every bonus-GFA scheme, balconies, green features and the rest, under a single ceiling: total bonus GFA could not exceed 10% of the site's allowable Master Plan gross plot ratio. That stopped developers from stacking multiple incentives to push a project beyond the cleanup's intent. It is plumbing rather than a layout change, but it is why "bonus area" in any condo since has a hard limit.
One feature of this framework matters at the other end of a building's life: bonus GFA does not carry forward on redevelopment. When a site is eventually torn down and rebuilt, its development potential reverts to the base Master Plan plot ratio, the bonus is a one-generation entitlement for the specific building, not a permanent uplift to the land's value (DC09-03).
Source: URA circular DC09-03, "Framework for Managing Bonus GFA Incentives" (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc09-03).
Private Enclosed Spaces (PES), typically the ground-floor patios attached to first-storey units, and the equivalent Private Roof Terraces (PRT) at the top of a building, were among the most exploited free area of all. Before January 2013 a PES or PRT counted as neither normal GFA nor bonus GFA: invisible to URA's budget, yet sold to buyers as strata area. URA's DC13-01 ended that, folding PES and PRT into the same 10% bonus-GFA pool that balconies use. Developers could no longer hand out unlimited free outdoor space, and ground-floor PES units stopped being the quiet margin machine they had been.
The change was not retroactive. PES and PRT approved before 12 January 2013 are grandfathered, they are not counted towards the development's GFA, and URA's current guidance still says so explicitly (https://www.ura.gov.sg/Corporate/Guidelines/Development-Control/Residential/Flats-Condominiums/Balconies-PES-PRT). So a ground-floor patio on a 2010 project and one on a 2015 project may look identical and yet have completely different histories on the developer's GFA ledger.
Source: URA circular DC13-01, effective 12 January 2013 (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc13-01); grandfathering and current PES/PRT rules per the URA Flats-and-Condominiums guidelines page.
Two URA circulars, DC13-10 (effective 1 November 2013) and DC14-27 (effective 9 December 2014), made the balcony bonus conditional. Issued jointly with BCA, DC13-10 set up a two-tier system: a developer could claim up to 3% additional GFA for balconies if the project met a baseline buildable-design score, and up to the full 10% only if it also adopted more productive construction methods such as drywall and prefabricated bathroom units. Developers applied to BCA first, then URA, and lodged a security deposit that was forfeit if the productivity conditions were not met by completion. DC14-27 then adjusted the second-tier conditions of that scheme.
This is less about your layout and more about why so many condos from the mid-2010s onward are built from precast modules. The carrot of bonus balcony area was used to modernise how Singapore builds.
Sources: URA circulars DC13-10 (effective 1 November 2013, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc13-10) and DC14-27 (effective 9 December 2014, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc14-27) on balcony bonus and buildability.
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The shoebox boom of 2011–2012, tiny sub-500 sqft units packed into outside-Central-Area sites, prompted URA to cap how many units a developer could squeeze from a site. The control is a divisor: maximum units = GFA divided by a set figure.
*This is a cap on unit count, not a minimum on unit size. This is the single most misunderstood rule on this page, so it is worth being precise. Dividing a fixed GFA by a larger number simply permits fewer units, which forces the average* unit size up across the project. It does not set a floor under any individual unit. A developer can still build a studio; they just have to balance it with something larger so the project average clears the divisor. URA itself describes the formula as deriving "an upper bound figure" for the unit count (URA Guidelines on DUs in Non-Landed Residential Developments, https://www.ura.gov.sg/Corporate/Guidelines/Development-Control/Residential/Flats-Condominiums/Maximum-Number-DU).
The 2019 rule also added a unit-mix guideline. Alongside the higher divisor, DC18-06 advised developers to provide a genuine spread of sizes outside the Central Area. As a guide, URA pointed to a development where about 20% of units have a net internal area of 100 sqm or more, and where units of 50 sqm or smaller do not exceed about 20%. It is framed as guidance rather than a hard quota. "Net internal area" here means living space measured to the middle of the walls, excluding voids, balconies, AC ledges and other external areas. URA later judged this mix rule "effective in achieving a good mix of both smaller and larger units" (URA circular DC22-10, para 2, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc22-10).
Two more details worth knowing. The GFA used in the divisor excludes bonus GFA and excludes any strata landed units, only the regular residential condo GFA is divided by 85 (or 100). Separately, URA's handbook carries a softer island-wide advisory: as a guide, every self-contained dwelling unit should be at least 35 sqm net in internal area. That 35 sqm advisory is a per-unit lower bound; the 85/100 sqm divisor is a project-average control. Both run at the same time, and neither applies to HDB flats or serviced apartments (URA DU guidelines page).
What it did to the market. Raising the divisor from 70 to 85 sqm means the same site yields roughly 18% fewer units (in the 100 sqm estates, about 30% fewer). The result was fewer shoebox-heavy projects: layouts shifted toward one-bed-plus-study and two-bedders as the practical floor, fewer units per launch, and a higher total price per unit even when PSF held flat. New small-unit sales fell from 3,480 in 2012 to 1,795 in 2013 after the earlier caps took hold.
Sources: URA circulars DC11-14 (issued 23 November 2011, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc11-14) and DC12-13 (2012) setting the unit-count cap, and DC18-06 raising it (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc18-06). The 20%/20% unit-mix rule, the bonus-GFA and strata-landed exclusions, and the 35 sqm advisory are from DC18-06 / DC22-10 and the live URA DU guidelines page. The ~18% and ~30% figures follow directly from the 70-to-85 and 70-to-100 change. The 2012-to-2013 fall in new small-unit sales (3,480 → 1,795) is from property commentary based on URA caveat data, not a URA release.
The same week, URA's DC18-07, its "Revision to the Balcony Incentive Scheme", made the most consequential balcony changes since 2001. It cut the bonus-GFA cap for balconies, PES and PRT combined from 10% to 7% of the development's residential GFA. URA's reason was that some projects had "excessively large balconies in relation to the size of the indoor spaces of a unit," and that buyers who didn't want a balcony struggled to find a unit without one (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc18-07).
The same circular added several rules that shape every post-2019 balcony you will see:
Developers can still reach 10% total bonus GFA, but only by stacking other schemes, the Green Mark Bonus and the Indoor Recreation Space Bonus, on top of the 7% balcony allocation. And as with all bonus GFA, none of it forms the site's future redevelopment potential. The big-balcony era didn't end overnight, but this is the point at which it began to taper.
Source: URA circular DC18-07, "Revision to the Balcony Incentive Scheme," effective 17 January 2019 (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc18-07); 40%-open and 1.3 m parapet rules per the current URA Balconies/PES/PRT guidelines page.
The 2019 reform applied the 7% cap to PES and PRT as well, but, importantly, not the 15%-of-net-internal-area per-unit cap or the 1.5 m minimum width. DC18-07's own footnote states that PES and PRT "will not be subject to the above guidelines"; they are governed only by the 7% development-level bonus cap. What they must keep is their semi-outdoor character:
A useful myth-buster: simply covering a PES does not turn it into regular indoor GFA. PES has sat in the bonus-GFA system since 2013 whether covered or not, and the 2023 harmonisation confirmed that PES and PRT count as GFA "even if uncovered." Only full permanent enclosure changes its character.
Source: URA Development Control, Balconies, PES and Private Roof Terraces (https://www.ura.gov.sg/Corporate/Guidelines/Development-Control/Residential/Flats-Condominiums/Balconies-PES-PRT); DC18-07 footnotes; DC22-09 Appendix 2.
Six months after the big 2019 changes, URA issued DC19-11, refining how GFA is calculated for sky terraces, pedestrian linkages, balconies and mechanical-and-electrical spaces, with immediate effect. The refinements were procedural, aimed at clearer, more objective measurement for the architects and engineers who submit plans, not at changing what a buyer experiences. It included a "credit" mechanism: floor space previously approved as GFA but no longer counted under the refined rules could offset additional floor space in amendment submissions. Buyer-facing impact is negligible; it is listed here for completeness, because plans submitted from 5 July 2019 follow this slightly tighter regime.
Source: URA circular DC19-11 (effective 5 July 2019, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc19-11).
For decades, the rules above lived scattered across dozens of circulars, each amending the last. In 2020, URA's DC20-07 published a consolidated GFA Handbook, a single, public online reference that lists every architectural element alphabetically (bay windows, balconies, ledges, planter boxes, PES, PRT, voids, RC slabs within voids, floors under pitched roofs, and more) and states, with diagrams, whether each counts as GFA and under what conditions. The handbook does not change any rule; it makes the cumulative history navigable, and it is updated in place, its pages now carry "last updated" dates in late July 2023, reflecting the harmonisation changes below. For anyone trying to verify the rule that was in force when a particular project was approved, the handbook is the authoritative starting point (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc20-07).
Source: URA circular DC20-07, "New Handbook on Gross Floor Area (GFA) and New Landed Housing E-Advisor" (2020).
The 85 and 100 sqm average rules never applied to the Central Area, where small units kept proliferating. URA's DC22-10, issued in October 2022 (effective 18 January 2023), addressed that: in the 11 Central-Area planning zones, Outram, Museum, Newton, River Valley, Singapore River, Marina South, Marina East, Straits View, Rochor, Orchard and Downtown Core, at least 20% of a development's units must have a net internal area of 70 sqm or larger. Studios are still allowed; the rule sets a floor on the share of bigger units, not a ceiling on small ones. At least one in five units in a new city-centre project must be family-sized. Outside the Central Area, DC22-10 carried forward the existing 85/100 sqm divisor and the 20%/20% mix rule unchanged, it consolidated the framework and extended it downtown rather than replacing it.
Source: URA circular DC22-10, issued 18 October 2022, effective 18 January 2023 (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc22-10).
The most recent and most misread change. For decades, four agencies measured floor area on different bases for the same building, a genuine mess that forced architects to compute multiple sets of areas and left homeowners confused. Before June 2023 there were at least four definitions in play:
DC22-09, a landmark circular co-signed by URA, SLA, BCA and SCDF, aligned them. It made four headline changes (DC22-09, para 5, https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc22-09):
It applies to development applications from 1 June 2023 and to Government Land Sales sites from 1 September 2022 (the publication date). Projects with a valid planning permission granted before 1 June 2023 keep the old rules. There is also a new procedural requirement: architects must now draw proposed strata boundaries as a separate layer in their CAD/BIM submissions, and finalise them early, because, with GFA now equal to strata area, a late change to strata boundaries directly changes the GFA figure.
The two changes a buyer feels most are the AC-ledge and void rules above: you no longer pay PSF for an exclusive AC ledge that you can't use (developers now shrink it or keep it common property), and double-volume voids no longer pad a penthouse's title. One property analyst estimated AC-ledge space was costing Singapore's private home owners around S$780 million a year before the change.
The headline effect: a newer unit's stated strata area can be around 5% smaller on paper than a physically similar pre-2023 unit, not because the home shrank, but because inflated, non-liveable space stopped being counted. The smaller number is the more honest one. When you compare a 2024 launch's PSF to a 2021 project's, you are often comparing a clean number to a padded one.
Sources: URA circular DC22-09, the URA/SLA/BCA/SCDF floor-area harmonisation, with Appendices 1–4 (https://www.ura.gov.sg/Corporate/Guidelines/Circulars/dc22-09). The ~5% reduction in stated strata area (efficiency falling from near 100% to about 95%) is a property-consultancy estimate for new projects whose applications were submitted on or after 1 June 2023, not a URA figure and not retroactive to existing units. The ~S$780 million-a-year AC-ledge cost is an estimate by property analyst Ku Swee Yong (circa 2017), not a government statistic.
Harmonisation didn't only affect new launches, it cleaned up a genuine headache for owners doing additions-and-alteration (A&A) works on existing units.
The classic case is a double-volume void. Voids have always been excluded from URA's GFA. But because SLA's old strata measure could include a void, an owner who slabbed over that void to create a mezzanine room found something strange: their strata area didn't change, yet their GFA jumped, because the new slab created covered floor that URA counted. After June 2023 the logic is clean: all voids are out of strata area, and all strata area is GFA, so slabbing over a void clearly creates new strata area which is then GFA. Building a mezzanine inside a double-height condo unit is therefore a GFA-consuming act that needs an amendment to the development's planning permission. URA's handbook even has a dedicated entry for "reinforced concrete (RC) slabs within voids," the technical name for exactly this kind of added mezzanine floor.
A related rule catches loft and attic spaces under sloped roofs: if the roof height from the springing line to the ridge is 1.5 m or more, the floor beneath it counts as GFA; below 1.5 m it doesn't. This is the rule that decides whether a penthouse or townhouse loft is "real" countable floor or just headroom (URA GFA Handbook, Floors, https://www.ura.gov.sg/Corporate/Guidelines/Development-Control/gross-floor-area/GFA/Floors).
For A&A specifically, the transitional rule is narrower than for new builds: existing approved voids keep their old treatment, and only new voids proposed in A&A applications submitted on or after 1 June 2023 without a valid permission fall under the new rules. Minor works are assessed case by case.
Sources: URA circular DC22-09, Appendices 2–3 and implementation section; URA GFA Handbook, Floors and the RC-slabs-within-voids entry. The standalone RC-slabs handbook entry is a named GFA item; its exact wording was not separately verified line-by-line here, so it is described in general terms.
A practical cheat-sheet from the timeline. First find the year, look for the planning-permission date or launch year on the sales brochure, or check the project's transaction history. Then apply the era:
The most useful single move, in any era: ask the agent or developer to break the quoted strata area into (a) net internal area, the enclosed, air-conditioned living space, and (b) everything else, balcony, PES, PRT, AC ledge, bay window, planter. The PSF that matters for daily life is the one on (a).
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Take two three-bedders that both list at, say, 1,100 sqft, both quoted at the same PSF. (The figures here are illustrative, to show how the rules interact, not URA numbers.)
The 2007 unit was drawn under the old rules. Its 1,100 sqft includes a bay window in each of the three bedrooms and the living room, plus a couple of planter boxes off the balcony, none of which counts against the developer's GFA budget, all of which you pay PSF for. It also has a generous balcony from the up-to-10% bonus era and an AC ledge folded into the strata area. Add the bay windows, planters, ledge and oversized balcony together and a meaningful slice of that 1,100 sqft, in the most padded older units, approaching a quarter, is ledge, trough, outdoor or unusable space. The liveable floor behind the headline number is smaller than it looks.
The post-2023 unit was drawn after harmonisation. Its 1,100 sqft is measured to the middle of the walls, excludes any void, and, if the developer kept the AC ledge as common property, excludes that too. Its balcony is capped at 15% of net internal area. Almost all of the 1,100 sqft is genuinely usable interior plus a modest, controlled balcony. If anything, a post-2023 unit that lists smaller than the 2007 one can be the bigger home to actually live in.
Same headline size, same PSF, and yet, unit-for-unit, the newer one gives you more floor you can stand on. That is the whole point of the fifteen-year cleanup: the number on the page has been getting steadily more honest. The era is part of the price. Two units at the same PSF from different years are not the same deal.
haio publishes from government and primary sources: URA, SLA, BCA and MND.
Estimate only, not financial advice. A model-generated guide from public data, not a formal valuation; actual prices and bank valuations may differ, so verify before acting. haio accepts no liability for decisions made in reliance on it.