Gross floor area (GFA) is the number Singapore’s planners use to cap how much a site can hold. Net floor area (NFA) is the usable space left once you subtract the parts that earn no rent or give no comfort, such as walls, lifts, stairs and shared corridors. They answer two different questions. GFA asks how big the building is. NFA asks how much of it you can actually use. If you are buying, leasing or valuing a property, you need to know which one a number refers to before you compare it with anything else.
TL;DR
- GFA is the regulatory measure. The Urban Redevelopment Authority (URA) uses it as a key metric to control the bulk and intensity of developments.
- NFA is a usable-space idea, not a current URA planning measure. It was used for commercial intensity before 1 September 1989, when GFA replaced it.
- Since 1 June 2023, URA, SLA, BCA and SCDF share harmonized floor area definitions, so older documents may not match newer ones.
- Never compare two floor area figures until you know the source, the date and what each one includes.
Table of Contents
- What GFA means in Singapore
- What NFA means, and why you will not find it in URA’s rulebook
- GFA vs NFA at a glance
- How the definitions were harmonized in 2023
- Why the same building can show different areas
- What the gap between GFA and NFA tells you
- A worked example: comparing two offices
- How to read floor area in listings and new launches
- Our perspective
- Where we can help
- FAQ
- Sources
What GFA means in Singapore
URA defines GFA as the total area of covered floor space. It includes the half thickness of external walls and facade elements such as railings and curtain walls, and it excludes voids. The URA Gross Floor Area handbook also sets out the general principles: all covered floor area counts, uncovered areas used for commercial purposes count, and all strata areas count, whether or not they are accessible or usable, unless a specific exemption applies.
That last point matters. GFA is a planning and entitlement number. It is not a promise about how pleasant, efficient or lettable a space is. A strata area that nobody can comfortably use still counts toward GFA.
The handbook also deals with details that often surprise people:
- Floors under pitched roofs count as GFA where the height from the springing line to the ridge is 1.5 m or more, according to URA’s guide on floors.
- The same guide counts intermediate load-bearing floors, perforated floors and areas under raised platforms where the height exceeds 1.5 m.
- In mixed-use developments, common areas are either attributed to a specific use if used exclusively for it, or apportioned using a weighted average of the Master Plan zone quantum mix, per URA’s GFA related matters page.
For a buyer, the takeaway is simple. GFA tells you what the developer or owner is allowed to build and what the authorities have approved. It is the backbone of site value, redevelopment potential and plot ratio discussions.
What NFA means, and why you will not find it in URA’s rulebook
NFA has no single legal definition in Singapore today. In everyday use it means the floor area you can occupy and use after removing the structural and shared elements. Think of the area inside your own unit or tenancy, excluding common lobbies, lift cores, risers and similar neutral areas.
There is history here. URA explains that before 1 September 1989, residential intensity was controlled by population density, while commercial intensity used net floor area excluding neutral areas. From that date, both were standardised under the GFA method. So the old residential-versus-commercial split is mostly a story about how rules used to work, not a separate GFA definition you apply today.
It also explains why old buildings can look odd on paper. For developments approved before 1 September 1989, URA says the approved building has to be recomputed under the prevailing GFA definition. A figure from an older approval and a figure on a modern plan may not be describing the same thing.
When someone quotes “NFA” to you, ask what they mean. It may be a landlord’s lettable area, an agent’s estimate of usable area, or a consultant’s efficiency calculation. It is only as reliable as the method behind it.
GFA vs NFA at a glance
| GFA | NFA (usable area) | |
|---|---|---|
| Purpose | Controls building bulk and intensity | Shows space you can occupy and use |
| Who sets the rules | URA, with harmonized definitions across agencies | No single official planning definition; depends on the document |
| Includes shared areas | Often yes, subject to URA’s rules and exemptions | Usually excluded |
| Counts unusable strata area | Yes, all strata areas count | Usually not, if the space cannot be used |
| Best for | Site potential, redevelopment, approvals | Day-to-day use, layout efficiency, rent per usable square foot |
Treat the table as a guide to how the terms are normally used. Always confirm the definition in the actual document in front of you.
How the definitions were harmonized in 2023
For years, different agencies measured floor area differently. Under a URA circular, URA, the Singapore Land Authority (SLA), the Building and Construction Authority (BCA) and the Singapore Civil Defence Force (SCDF) harmonized their floor area definitions effective 1 June 2023. Under the harmonized approach, floor area is calculated to the middle of the wall, all strata areas are counted as GFA, and voids are excluded from strata area. The revised definitions apply to URA applications submitted on or after that date, subject to stated exceptions.
Another point from URA: qualified persons must show both GFA and strata boundaries clearly on submitted floor plans, so that all strata areas are computed as GFA (GFA related matters).
What this means for you: a figure from before mid-2023 and one from after may follow different measuring conventions. Before comparing two buildings, check the date of the plan or approval behind each number.
Why the same building can show different areas
There are several honest reasons two documents disagree.
Different agencies, different purposes. BCA’s Statistical Gross Floor Area (SGFA) is not URA GFA. BCA uses it to gauge the extent of building works, and it includes all floor areas in a general building plus many constructed or covered areas such as landscape decks, canopies, walkways, linkways, car parks, driveways, ramps and loading bays, according to BCA’s SGFA page. If you see a larger number in a BCA context, that is not an error.
Rule changes over time. URA’s 1993 circular treated covered floor areas and uncovered commercial areas as GFA with stated exceptions, and said balconies and air-conditioning ledges were not counted. In July 2019, URA refined the rules for sky terraces, linkages, balconies and mechanical and electrical spaces. Under that change, previously approved GFA that no longer counted could offset additional floor space in amendment or A&A submissions until exhausted. A building’s headline numbers can therefore reflect the rules of its era.
Measurement point. Measuring to the wall’s middle, the inner face of the wall or the centerline of a party wall gives different totals for the same unit.
Marketing choices. A brochure may present the area that sounds most generous. That is why the definition matters more than the number.
The same issue shows up overseas. In England and Wales, for instance, GEA, GIA and NIA each have their own measuring rules for rating purposes. If you read foreign guides or deal with an overseas landlord, do not assume their “net” matches ours.
What the gap between GFA and NFA tells you
The difference between the two figures is a rough signal of how efficiently a building uses its floor plate. The reasoning is the same whether you are an owner, investor or tenant:
- A small gap suggests most of the area you see on paper is usable.
- A large gap suggests a lot of space goes to cores, corridors, plant rooms, thick walls or awkward geometry.
How you use that depends on who you are.
Home buyers
Two units quoted at the same size can feel very different if one has an awkward layout or a long entrance corridor. When you view a unit, walk the usable rooms and think about where furniture fits. Ask which area basis the quoted size uses, and check it against the floor plan.
Investors
Yield is a function of rent against price, and both are tied to a size. If the size basis differs between two properties you are comparing, your price per square foot and your rent per square foot are not comparable. Normalize both to the same basis before ranking deals. Our commercial property investment guide walks through how we think about yield for commercial assets, and the commercial market guide covers the wider context.
Landlords
A lettable area figure that you can defend wins trust with tenants and avoids disputes later. Know what your lease says the rent is charged on, and keep the plan that supports it.
Tenants and business owners
You pay for what the lease says you pay for. Check whether the quoted area is the space you occupy or includes a share of common areas, and ask what you pay beyond base rent. URA’s office rental dataset, for example, is built from rental contracts submitted to IRAS for stamp duty and reports gross rent, including base rent and connected charges such as service charge, equipment-hire fees and advertising or promotion charges. The dataset description does not define rent by URA planning GFA. So a market rent per square foot is a benchmark, not a quote for your floor area basis.
If you are choosing between lease structures too, our guides on gross versus net lease and commercial lease types and key terms will help. Note that “gross” and “net” there describe who pays outgoings, not how floor area is measured. It is an easy mix-up.
A worked example: comparing two offices
This is an illustration, with invented numbers, to show the method.
Office A is quoted at 2,000 sq ft. Office B is quoted at 1,800 sq ft. Office A looks bigger and cheaper per square foot. But suppose A’s figure includes a share of common areas, while B’s figure covers only the space you occupy. After you ask both landlords for the basis and get the plans, A’s occupiable area might turn out to be smaller than B’s.
Steps to avoid this trap:
- Ask each landlord or agent what the quoted area includes and excludes.
- Request the floor plan and the document that supports the figure.
- Note the date of the plan against the 1 June 2023 harmonization.
- Convert both offers to the same basis, then compare rent per square foot and total monthly cost.
- Check the layout. Columns, bays and corridors can make a smaller area work better than a larger one.
Our guide on what to consider when choosing office space in Singapore covers the other side of the decision.
How to read floor area in listings and new launches
A short checklist you can use on any property:
- Find the basis. Does the figure say strata area, GFA, lettable area or usable area? If it says nothing, ask.
- Match like for like. Compare only figures on the same basis and from comparable dates.
- Check the plan. URA requires strata boundaries and GFA to be shown on submitted plans, so the plan should tell the story.
- Look at the layout. Efficiency shows in how rooms connect, not only in totals.
- Mind the building’s age. Older approvals may follow earlier conventions, and pre-1989 approvals are recomputed under current GFA rules.
- Ask about exemptions and features. Pitched roofs, raised platforms, voids and mezzanines each have their own treatment under URA’s rules.
For new launches, treat the brochure and the legal documents as separate things. Use the brochure to see the product, and the approved plans to verify the numbers. Our team tracks current projects on the SG New Launches page.
Our perspective
We see floor area confusion cost people money in quiet ways. A buyer pays a premium for a size that does not mean what they thought. A tenant signs a lease on a figure they never tested. An investor ranks two deals on numbers that were measured differently.
Our approach starts with the objective, whether that is own stay, income or an eventual exit, and then works backward to the numbers that matter. For an own-stay buyer, usable layout matters most. For an investor, a consistent basis for comparison matters most. For a commercial tenant, the lease wording matters most. Aman’s background spans engineering and real estate, which means reading floor plans and approvals is a normal part of how we vet a property before we put it in front of a client.
Our rule of thumb: never negotiate on a number until you can say in one sentence what it measures.
— Aman
Where we can help
If you are comparing properties and the numbers do not line up, we can help you put them on the same footing before you commit. Our consultancy covers valuation, advisory, sales and leasing, and you can browse commercial listings or commercial rentals. If a valuation is part of your decision, our explainer on bank valuation versus market valuation is a good next read.
Costs also change with the asset type. If you are buying a commercial unit, see how GST applies to commercial property before you finalize your budget.
FAQ
Is NFA an official term in Singapore?
Not as a current URA planning measure. URA controls development intensity through GFA. NFA was used for commercial intensity before 1 September 1989, and today the term is mainly used informally for usable or lettable area. Always check how a specific document defines it.
Does GFA include walls and balconies?
GFA includes half the thickness of external walls, and under the harmonized definitions, floor area is calculated to the middle of the wall. Balconies have been treated differently over time: URA’s 1993 circular said they were not counted, and the 2019 refinements adjusted rules for sky terraces and balconies. Check the rules that applied when the building was approved.
Why does my unit’s size differ between documents?
Different documents serve different purposes and may follow different conventions or dates. BCA’s statistical GFA, for example, serves a different purpose from URA GFA. Ask each source what its figure includes and compare only like for like.
Which should I use to compare rents or prices?
Use whichever area basis the contract charges on, and convert other offers to that basis. For a lease, the clause that defines the rentable area decides what you pay on. For purchases, compare on the same stated basis and verify it against the plan.
Sources
- URA: Gross Floor Area handbook
- URA: GFA Related Matters
- URA: Floors
- URA Circular: Harmonisation of Floor Area Definitions
- URA Circular: Revised Gross Floor Area Definition (1993)
- URA Circular: Refinements to GFA Rules (2019)
- BCA: Statistical Gross Floor Area and Plan Fees
- URA: Commercial Office Rental Analysis
- VOA: Code of measuring practice for rating purposes
