On the planet of commercial realty, a building's Net Internal Area (NIA) is necessary for communicating the usable space, determining lease rates, and estimating a residential or commercial property's worth. This article talks about the nuances of NIA, walks you through the actions in calculating it, and describes how modern tools like RoomSketcher can improve this procedure.

What is Net Internal Area (NIA)?

Net Internal Area (NIA) is a measurement used in industrial property to identify the "functional area" within a structure. Usable space implies the readily available locations for occupants' special or sole usage, such as offices, retail area, laboratories, and manufacturing. Areas left out from an NIA computation consist of common locations such as shared lobbies, bathrooms, or elevators.

NIA is an important metric for landlords and occupants, as it supplies a standardized way to examine the real location available for profession and use within a structure.

Note that meanings of NIA - including which areas count towards it and which do not - vary worldwide. Hence, it's best to check with local authorities or an expert appraiser for your place's most utilized measurement requirements. Many countries are moving towards International Residential or commercial property Measurement Standards (IPMS), established by more than 80 specialists and non-profit organizations, to record international residential or commercial property measurement standards.

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 typical locations. In other words:

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

Here are a number of ways to determine NIA:

Option 1: Use an existing blueprint or floor plan

If you have an existing blueprint or layout for the building, you can import it into floor plan software like RoomSketcher. With RoomSketcher's built-in location calculator, you can get your NIA result in seconds - simply click to leave out the typical locations on the layout and then pick the "Internal Zone Area" estimation (which immediately omits the internal walls for you).

See Calculate the Total Area of a Flooring Plan for more details on RoomSketcher's location estimations.

Option 2: Measure onsite

You can also 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 measure the internal walls and common spaces and deduct them. Or, if you don't know the structure's GIA, you can build up all the functional space to calculate the NIA. For instance:

Start with a walkaround - Walk around the residential or commercial property to get a concept of the shape and number of floorings.
Sketch the external walls on paper or tablet - Make a sketch of the residential or commercial property shape or produce a digital sketch utilizing flooring plan 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, note the common locations intended to be shared among tenants so you do not include them in the computation.
Get the measurements - Now, use a tape procedure, roto wheel, or a laser to figure out the size of any room or area that counts as usable space. It's handy to divide the areas into rectangular shapes and measure from the within all walls. Once you have actually determined up one side of a rectangle, go ahead and measure the other direction. Remember, don't include any typical locations or shared spaces amongst renters.
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 flooring. Repeat for all floorings, and sum the result to compute the building's Net Internal Area (NIA).
What Does Net Internal Area Include?

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

Exclusive use space, such as all spaces or locations planned to be used by a single company or occupant, such as reception locations, workplaces, training rooms, laboratories, workshops, retail area, producing area, storeroom, staff or break rooms, and so on.
Exclusive usage atriums and entryway halls used by one company or tenant.
Built-in kitchen cabinetry and storage within unique usage locations.
Removable partitions. Include the thickness of non-permanent partitions.
Ramps and other sloping or stepped aspects if they are within the exclusive use area.
Ventilation or heating unit locations inside an unique use area.

"Because requirements vary somewhat around the world, examine with your local authorities for a total list of the standard additions in your location. For example, expect you use the International Residential or commercial property Measurement Standards (IPMS). Because case, your computation would consist of columns and tenant parts of shared walls (likewise called celebration walls.)"

Net Internal Area Exclusions

NIA estimations exclude typical areas (likewise called balance locations) because they are not thought about specific to a particular occupant. Examples consist of:

- Shared entryway halls, lobbies, atriums, and landing areas.
- Shared bathrooms, toilets, bathrooms, and janitorial rooms that keep products and equipment utilized to maintain common locations in a building.
- Lifts or elevators that more than one resident usages.
- Internal structural walls that separate tenants.
- Any locations managed by external authorities such as utility business.
- Spaces that are taken up with cooling and heating devices, and so on, if the equipment makes the rest of the space unusable.
- Any room or location with a ceiling height lower than 1.5 m (5ft).

Top RoomSketcher Tip

"Because standards vary somewhat around the world, check with your regional authorities for a complete list of the standard exclusions in your location."

NIA Compared: How It Differs from Other Measurement Standards

Let's take an appearance at the distinctions in between Net Internal Area (NIA) and other estimations. For extra information on measurement requirements, see GIA Explained, and What is Gross Living Area?

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

The Gross Floor Area (GFA) is generally specified as the total area of the building. GFA includes external walls and all areas inside the structure, including entrance lobbies and other typical locations, lifts/elevators, stairwells, mechanical devices locations, passages, and so on. In contrast, NIA does not consist of external or internal walls or typical areas.

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

GIA (likewise called Gross Internal Floor Area) includes everything measured from inside the external walls, including internal walls and common areas in a building. On the other hand, 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 residential rather than industrial residential or commercial properties. As such, the measurements are not related. For more information 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 quantity of usable area within a structure and does not consist of external walls, internal walls, or typical areas. On the other hand, Gross Building Area describes the total location of a structure and consists of common locations along with internal and external walls.

GBA is comparable to Gross Floor Area (GFA) in the industrial world.

The Importance of Accurate NIA Calculation

The Net Internal Area is essential for numerous purposes:

Rentable Area: In commercial leases, lease is often based upon the NIA, and tenants are charged based on the functional area they will inhabit or utilize, plus a portion of the common locations.
Space Planning: For occupants and designers, NIA helps in area planning and developing the layout of offices, conference room, and other functional areas.
Comparisons: NIA provides a standardized metric for comparing various residential or commercial properties. When examining prospective spaces, renters and proprietors can use NIA to compare the cost and performance of area.
Lease Negotiations: NIA is an essential consider lease negotiations. Understanding the NIA permits tenants and property owners to work out lease terms, including lease, maintenance expenses, and other charges based upon the functional area.
Building Efficiency: Landlords and residential or commercial property managers use NIA to assess the efficiency of a building's layout and to make improvements that make the most of the functional space.

Thus, NIA should be measured properly and utilizing 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 special functional space of a single company/tenant. Shared stairways and ramps (used by numerous lessees) are omitted from the NIA measurement.

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

Some leases utilize the Gross Lease Area as a basis for rent calculations. A customer's Gross Leasable Area typically includes:

- Their functional location or NIA.

- The space occupied by any external walls adjacent to their area. For instance, a glass shopfront or a plain wall.

- The space inhabited by their 1/2 of any shared internal walls or celebration walls.

- A pro-rata share of the common location. For example, if a tenant will inhabit 1/3 of the functional area, their Gross Leasable Area computation would consist of 1/3 of the typical location space.


If a structure is inhabited by a single tenant, then the GLA is the same as the GFA.

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

Some leases use the Net Leaseable Area (NLA) as a basis for rent estimations. A client's Net Leasable Area or Net Leasable Area is normally defined as their functional location (or portion of the NIA) inside a structure. Tenants might then pay an extra pro-rata charge for maintenance and using the common space.

Making NIA Measurements Easy and Accurate

In summary, Net Internal Area is an important metric in commercial property that assists figure out the actual usable area within a building. It plays a role in lease contracts, space preparation, and general performance assessments for both property managers and tenants. It is one of numerous standard measurements used in business genuine estate.

To precisely calculate NIA, you can measure up the usable area in a building or use Layout Software, like RoomSketcher, to enhance the procedure of determining NIA.

Learn what Gross Living Area (GLA) suggests, why it is essential, and how to properly determine it for a residential or commercial property. Discover our expert guide.