On the planet of industrial property, a structure's Net Internal Area (NIA) is necessary for communicating the functional space, computing lease rates, and approximating a residential or commercial property's worth. This post goes over the nuances of NIA, walks you through the actions in computing it, and describes how modern tools like RoomSketcher can enhance this procedure.

What is Net Internal Area (NIA)?

Net Internal Area (NIA) is a measurement used in business property to determine the "functional area" within a building. Usable area indicates the available locations for renters' exclusive or sole usage, such as workplaces, retail space, labs, and manufacturing. Areas excluded from an NIA computation consist of common areas such as shared lobbies, restrooms, or elevators.

NIA is a necessary metric for proprietors and occupants, as it offers a standardized way to assess the real area readily available for occupation and usage within a building.

Note that definitions of NIA - consisting of which locations count towards it and which do not - vary worldwide. Hence, it's finest to examine with local authorities or an expert appraiser for your area's most utilized measurement requirements. Many countries are moving towards International Residential or commercial property Measurement Standards (IPMS), developed by more than 80 professionals and non-profit companies, to record international residential or commercial property measurement requirements.

Practical Tips on How to Measure and Calculate Net Internal Area

NIA is basically the overall internal area of a building minus the interior walls and common areas. To put it simply:

NIA = Gross Internal Area − (Interior Walls + Common Areas)

Here are a number of ways to calculate NIA:

Option 1: Use an existing plan or layout

If you have an existing blueprint or floor strategy for the building, you can import it into floor strategy software application like RoomSketcher. With RoomSketcher's built-in location calculator, you can get your NIA lead to seconds - simply click to exclude the common areas on the layout and after that choose the "Internal Zone Area" estimation (which automatically excludes the internal walls for you).

See Calculate the Total Area of a Floor Plan for additional information on RoomSketcher's area estimations.

Option 2: Measure onsite

You can likewise measure up the residential or commercial property if you don't have access to an existing floor strategy. If you understand the building's GIA, you can determine the internal walls and common spaces and deduct them. Or, if you do not understand the structure's GIA, you can add up all the usable space to calculate the NIA. For example:

Start with a walkaround - Walk around the residential or commercial property to get a concept of the shape and variety of floors.
Sketch the external walls on paper or tablet - Make a sketch of the residential or commercial property shape or produce a digital sketch using layout software application on your tablet.
Note the Usable Space vs the Common Space - Locate the areas or rooms that are usable space and mark these on your sketch. Also, keep in mind the typical locations planned to be shared among renters so you do not include them in the computation.
Get the measurements - Now, utilize a tape measure, roto wheel, or a laser to figure out the size of any space or location that counts as functional space. It's valuable to divide the locations into rectangular shapes and measure from the inside of all walls. Once you've measured up one side of a rectangle, go on and measure the other direction. Remember, don't include any common locations or shared areas among tenants.
Do the mathematics - Multiply the length and width of each rectangular shape to calculate its size. Combine all the rectangle-shaped usable areas on the floor. Repeat for all floorings, and sum the outcome to determine the building's Net Internal Area (NIA).
What Does Net Internal Area Include?

NIA explains just how much "usable area" a building's interior includes. Examples of areas to include in an NIA measurement are:

Exclusive usage space, such as all spaces or areas meant to be utilized by a single company or renter, such as reception locations, workplaces, training rooms, labs, workshops, retail space, producing space, storeroom, staff or break rooms, etc.
Exclusive use atriums and entrance halls used by one company or occupant.
Built-in cabinets and storage within special use areas.
Removable partitions. Include the density of non-permanent partitions.
Ramps and other sloping or stepped components if they are within the special usage location.
Ventilation or heating unit locations inside an unique use area.

"Because requirements vary a little worldwide, contact your regional authorities for a complete list of the standard additions in your area. For instance, expect you use the International Residential or commercial property Measurement Standards (IPMS). Because case, your estimation would consist of columns and tenant parts of shared walls (also called celebration walls.)"

Net Internal Area Exclusions

NIA computations leave out typical areas (also called balance areas) due to the fact that they are ruled out particular to a particular resident. Examples include:

- Shared entryway halls, lobbies, atriums, and landing locations.
- Shared washrooms, toilets, restrooms, and janitorial spaces that save materials and devices used to maintain typical areas in a structure.
- Lifts or elevators that more than one resident uses.
- Internal structural walls that separate tenants.
- Any locations controlled by external authorities such as energy business.
- Spaces that are taken up with heating and cooling devices, etc, if the devices makes the remainder of the space unusable.
- Any room or location with a ceiling height lower than 1.5 m (5ft).

Top RoomSketcher Tip

"Because requirements differ a little around the world, contact your regional authorities for a complete list of the standard exemptions in your location."

NIA Compared: How It Differs from Other Measurement Standards

Let's have a look at the distinctions between Net Internal Area (NIA) and other estimations. For additional details on measurement standards, see GIA Explained, and What is Gross Living Area?

Net Internal Area (NIA) vs. Gross Floor Area (GFA)

The Gross Floor Area (GFA) is normally specified as the overall location of the structure. GFA includes external walls and all locations inside the structure, consisting of entryway lobbies and other typical locations, lifts/elevators, stairwells, mechanical equipment areas, passages, etc. On the other hand, NIA does not include external or internal walls or typical locations.

Net Internal Area (NIA) vs. Gross Internal Area (GIA)

GIA (also understood as Gross Internal Floor Area) includes whatever determined from inside the external walls, consisting of internal walls and common areas in a structure. In contrast, NIA does not consist of the internal walls and typical locations.

Net Internal Area (NIA) vs. Gross Living Area (GLA)

Gross Living Area (GLA) is utilized for property instead of commercial residential or commercial properties. As such, the measurements are not related. To read more about GLA, see What is Gross Living Area, and How do you Calculate it?

Net Internal Area (NIA) vs. Gross Building Area (GBA)

Net Internal Area describes the amount of usable area within a building and does not include external walls, internal walls, or typical spaces. In contrast, Gross Building Area explains the overall location of a building and includes typical locations in addition to internal and external walls.

GBA resembles Gross Floor Area (GFA) in the industrial world.

The Importance of Accurate NIA Calculation

The Net Internal Area is necessary for various functions:

Rentable Area: In commercial leases, lease is often based upon the NIA, and occupants are charged based upon the functional space they will inhabit or use, plus a portion of the common areas.
Space Planning: For renters and designers, NIA assists in area preparation and creating the layout of workplaces, meeting spaces, and other functional spaces.
Comparisons: NIA offers a standardized metric for comparing different residential or commercial properties. When examining possible spaces, occupants and landlords can utilize NIA to compare the expense and performance of area.
Lease Negotiations: NIA is a key consider lease settlements. Understanding the NIA enables occupants and landlords to negotiate lease terms, including rent, upkeep costs, and other charges based on the functional space.
Building Efficiency: Landlords and residential or commercial property supervisors use NIA to assess the efficiency of a building's design and to make improvements that make the most of the usable space.

Thus, NIA must be measured correctly and using the agreed-upon standards in your area.

Frequently Asked Questions About NIA

Does the Net Internal Area (NIA) include stairs?

Stairs and ramps are consisted of in the NIA if they are within the exclusive functional space of a single company/tenant. Shared stairways and ramps (used by numerous lessees) are excluded from the NIA measurement.

What is the distinction between Net Internal Area (NIA) vs. Gross Leasable/Rentable Area

Some leases use the Gross Lease Area as a basis for lease calculations. A customer's Gross Leasable Area typically consists of:

- Their functional location or NIA.

- The space occupied by any external walls surrounding to their location. For example, a glass shopfront or a plain wall.

- The area occupied by their 1/2 of any shared internal walls or party walls.

- A pro-rata share of the typical location. For instance, if an occupant will occupy 1/3 of the usable area, their Gross Leasable Area computation would include 1/3 of the typical location space.


If a structure is occupied by a single renter, then the GLA is the exact same as the GFA.

What is the difference between Net Internal Area (NIA) vs. Net Leasable/Lettable Area?

Some leases utilize the Net Leaseable Area (NLA) as a basis for lease calculations. A customer's Net Leasable Area or Net Leasable Area is usually specified as their functional location (or portion of the NIA) inside a building. Tenants may then pay an extra pro-rata cost for maintenance and using the typical area.

Making NIA Measurements Easy and Accurate

In summary, Net Internal Area is an essential metric in commercial property that assists identify the actual functional area within a structure. It contributes in lease agreements, space preparation, and overall performance evaluations for both landlords and occupants. It is one of numerous basic measurements used in business realty.

To accurately determine NIA, you can measure up the functional space in a building or utilize Floor Plan Software, like RoomSketcher, to enhance the procedure of measuring NIA.

Learn what Gross Living Area (GLA) means, why it's essential, and how to precisely calculate it for a residential or commercial property. Discover our specialist guide.