Worldwide of business property, a structure's Net Internal Area (NIA) is very important for interacting the functional area, determining lease rates, and approximating a residential or commercial property's value. This short article talks about the subtleties of NIA, walks you through the actions in computing it, and explains how modern-day tools like RoomSketcher can simplify this process.

What is Net Internal Area (NIA)?

Net Internal Area (NIA) is a measurement used in business realty to identify the "usable space" within a structure. Usable area suggests the readily available locations for renters' special or sole use, such as offices, retail area, labs, and production. Areas excluded from an NIA estimation include common areas such as shared lobbies, toilets, or elevators.

NIA is an essential metric for property managers and occupants, as it supplies a standardized method to assess the actual area offered for profession and usage within a building.

Note that meanings of NIA - consisting of which areas count towards it and which do not - differ worldwide. Hence, it's finest to examine with local authorities or a professional appraiser for your place's most utilized measurement standards. Many countries are moving towards International Residential or commercial property Measurement Standards (IPMS), developed by more than 80 specialists and non-profit organizations, to record global residential or commercial property measurement requirements.

Practical Tips on How to Measure and Calculate Net Internal Area

NIA is essentially the total internal location of a structure minus the interior walls and common areas. In other words:

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

Here are a number of methods to calculate NIA:

Option 1: Use an existing blueprint or layout

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

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

Option 2: Measure onsite

You can also determine up the residential or commercial property if you don't have access to an existing floor plan. If you understand the building's GIA, you can determine the internal walls and typical areas and subtract them. Or, if you do not know the building's GIA, you can accumulate all the functional area to determine the NIA. For instance:

Start with a walkaround - Walk 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 layout software application on your tablet.
Note the Usable Space vs the Common Space - Locate the areas or spaces that are usable space and mark these on your sketch. Also, note the typical locations meant to be shared among renters so you do not include them in the estimation.
Get the measurements - Now, utilize a measuring tape, roto wheel, or a laser to identify the size of any room or area that counts as functional area. It's practical to divide the areas into rectangular shapes and measure from the within all walls. Once you've determined up one side of a rectangular shape, go on and determine the other direction. Remember, don't consist of any common locations or shared areas amongst tenants.
Do the mathematics - Multiply the length and width of each rectangle to calculate its size. Total all the rectangle-shaped functional areas on the flooring. Repeat for all floors, and sum the result to calculate the building's Net Internal Area (NIA).
What Does Net Internal Area Include?

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

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

"Because standards differ slightly worldwide, consult your regional authorities for a complete list of the basic inclusions in your location. For instance, expect you use the International Residential or commercial property Measurement Standards (IPMS). Because case, your computation would include columns and occupant parts of shared walls (also called party walls.)"

Net Internal Area Exclusions

NIA estimations omit common areas (also called balance locations) since they are ruled out particular to a particular resident. Examples consist of:

- Shared entrance halls, lobbies, atriums, and landing locations.
- Shared bathrooms, toilets, restrooms, and janitorial rooms that keep supplies and equipment used to keep common locations in a building.
- Lifts or elevators that more than one occupant usages.
- Internal structural walls that separate renters.
- Any locations controlled by external authorities such as energy business.
- Spaces that are taken up with heating and cooling devices, and so on, if the equipment makes the rest of the space unusable.
- Any space or location with a ceiling height lower than 1.5 m (5ft).

Top RoomSketcher Tip

"Because standards differ somewhat worldwide, contact your regional authorities for a complete list of the standard exemptions in your area."

NIA Compared: How It Differs from Other Measurement Standards

Let's take a look at the differences in between Net Internal Area (NIA) and other calculations. For extra info 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 generally defined as the total location of the structure. GFA consists of external walls and all areas inside the structure, consisting of entryway lobbies and other common locations, lifts/elevators, stairwells, mechanical devices locations, corridors, etc. In contrast, NIA does not consist of external or internal walls or typical areas.

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

GIA (also referred to as Gross Internal Floor Area) consists of everything determined from inside the external walls, consisting of internal walls and typical locations in a structure. In contrast, NIA does not consist of the internal walls and common 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 unrelated. To get 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 common areas. On the other hand, Gross Building Area describes the overall area of a building and consists of common areas in addition to internal and external walls.

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

The Importance of Accurate NIA Calculation

The Net Internal Area is essential for various purposes:

Rentable Area: In business leases, lease is typically based on the NIA, and renters are charged based upon the usable area they will inhabit or use, plus a portion of the common locations.
Space Planning: For tenants and designers, NIA assists in area preparation and designing the design of workplaces, conference rooms, and other practical areas.
Comparisons: NIA supplies a standardized metric for comparing different residential or commercial properties. When examining prospective areas, occupants and property owners can utilize NIA to compare the expense and performance of area.
Lease Negotiations: NIA is a crucial element in lease settlements. Understanding the NIA permits renters and proprietors to negotiate lease terms, consisting of rent, upkeep expenses, and other charges based upon the functional space.
Building Efficiency: Landlords and residential or commercial property managers use NIA to evaluate the efficiency of a building's design and to make improvements that maximize the usable space.

Thus, NIA should be measured properly and utilizing the agreed-upon requirements in your area.

Frequently Asked Questions About NIA

Does the Net Internal Area (NIA) include stairs?

Stairs and ramps are included in the NIA if they are within the special functional area of a single company/tenant. Shared staircases 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 area or NIA.

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

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

- A pro-rata share of the common location. For instance, if a renter will inhabit 1/3 of the usable space, their Gross Leasable Area calculation would include 1/3 of the common area 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 lease estimations. A client's Net Leasable Area or Net Leasable Area is normally specified as their usable area (or portion of the NIA) inside a structure. Tenants may then pay an extra pro-rata charge for maintenance and making use of the common space.

Making NIA Measurements Easy and Accurate

In summary, Net Internal Area is an essential metric in business real estate that assists identify the actual functional space within a building. It contributes in lease contracts, area planning, and overall effectiveness assessments for both landlords and tenants. It is among a number of standard measurements used in business genuine estate.

To accurately compute NIA, you can measure up the functional area in a building or use Floor Plan Software, like RoomSketcher, to enhance the process of determining NIA.

Learn what Gross Living Area (GLA) suggests, why it is very important, and how to precisely calculate it for a residential or commercial property. Discover our professional guide.