What Is Net Lettable Area (NLA)?
Net Lettable Area (NLA) is the actual floor space inside a commercial building that a tenant can occupy and is charged rent on, measured after excluding common areas, structural walls, lift and stair cores, risers and other shared services space. It is always smaller than Gross Floor Area (GFA), which measures the whole building to the outside of its external walls, because NLA only counts the space a tenant can actually use.
Key takeaways
- NLA is the usable floor space a commercial tenant leases and pays rent on — it excludes common areas, structural elements and shared services.
- NLA is always smaller than GFA, since GFA measures the entire enclosed building including cores, risers and shared circulation space.
- NLA is central to commercial leasing — rent, outgoings and fit-out budgets are usually calculated per square metre of NLA.
- Measurement conventions for NLA can vary between the Property Council of Australia method and individual lease terms, so always check which standard applies.
How Net Lettable Area Is Measured
NLA is measured from the inside face of the walls that enclose a tenancy — typically to the centre line of walls shared between tenancies, and to the internal face of external or corridor walls — then excludes any structural columns, risers or ducts that intrude into the space.
In Australia, NLA is most commonly measured according to the Property Council of Australia (PCA) Method of Measurement, though individual leases can specify their own method, so the figure quoted in a lease should always be checked against the definition it references.
What Net Lettable Area Excludes
NLA is a deliberately narrow figure — it strips out everything a tenant does not have exclusive use of, so it can be applied consistently to calculate rent across different tenancies in the same building.
- Common areas: foyers, corridors, shared bathrooms and kitchens
- Structural elements: columns, structural walls and load-bearing cores
- Vertical circulation: lift shafts, stairwells and fire stairs
- Services: risers, plant rooms, switch rooms and ductwork
- External areas: balconies and awnings, unless specifically included in the lease
NLA vs Gross Floor Area
NLA and GFA are often confused because both describe area, but they serve different purposes. GFA is the whole-building figure used for planning approvals; NLA is the tenant-facing figure used to calculate rent.
| Measure | What it captures | Who uses it |
|---|---|---|
| Net Lettable Area (NLA) | Usable tenant space only, excluding common areas, cores and services | Landlords and tenants, for rent and outgoings |
| Gross Floor Area (GFA) | Total enclosed floor space of the whole building, all levels | Councils and planners, and estimators for early benchmarking |
Efficiency ratio
The relationship between NLA and GFA is often expressed as an efficiency ratio — NLA divided by GFA. A ratio in the 80 to 90 per cent range is typical for a well-designed commercial floor; a lower ratio means more of the building is taken up by cores, structure and services.
Why NLA Matters for Commercial Fit-Outs
For a builder or fit-out contractor, NLA is the number that actually drives the job — it is the floor space that gets fitted out, so it is the figure a quantity takeoff should be measured against once a tenancy is handed over. GFA is useful in a whole-building planning context, but it overstates the area that will actually see joinery, partitions, flooring and services work.
MTH’s quantity takeoff tool measures directly from the uploaded tenancy plan, so a fit-out estimate is built on the real, measured NLA rather than an assumed efficiency ratio applied to GFA.
Frequently asked questions
What is the difference between NLA and GFA?
NLA is the usable floor space a tenant leases and pays rent on, excluding common areas, cores and services. GFA is the total enclosed floor space of the whole building, measured to the outside of the external walls, and is always the larger figure.
How is NLA calculated in Australia?
NLA is most commonly measured according to the Property Council of Australia Method of Measurement, taken from the inside face of enclosing walls and the centre line of walls shared between tenancies, excluding structure, cores and services. Some leases specify their own method, so it pays to check the lease document.
Does NLA include bathrooms and kitchens?
Shared bathrooms, kitchens and other common facilities are generally excluded from NLA, since they are not exclusively occupied by a single tenant. Amenities built entirely within a tenant’s own leased space are typically included.
What is a good NLA to GFA efficiency ratio?
An efficiency ratio — NLA divided by GFA — in the 80 to 90 per cent range is generally considered efficient for a commercial floor. A lower ratio suggests a larger share of the building is taken up by lift cores, structure and services.
Why does my lease quote a different NLA to my own measurement?
Differences usually come down to measurement method — a landlord may apply a different standard, or measure to a different wall reference line, to the one you or your surveyor used. Always check which method of measurement the lease refers to before comparing figures.
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