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Mastering Measurement for Real Estate: A Complete Guide to Total Living Area

Total Living Area (TLA) is a widely used term that defines the total amount of livable space within a residential property. In this guide, we’ll delve deeper into the meaning of TLA, explain how to calculate it using modern software tools like RoomSketcher, and compare TLA to other measurement standards.

Blog | Floor Plans
Total living area
Tony Gillen

What is Total Living Area (TLA)?

The Total Living Area (TLA) refers to the finished, heated living space of a residential lot or property. It includes above and below-grade areas and separate structures such as finished garages and accessory dwelling units. TLA provides potential residents with an accurate idea of all the living space that will be available to them on a particular property.

Measurement Standards and Conventions Vary

Note that definitions of TLA - including which areas count towards it and which don’t - vary worldwide. Hence, it's advisable to check with local authorities or a professional appraiser to determine the most commonly used measurement standards for your location.

Many countries are moving towards International Property Measurement Standards (IPMS), developed by more than 80 professionals and non-profit organizations, to document international property measurement standards. Other measurement standards include RICS (Royal Institution of Chartered Surveyors) and ANSI (American National Standards Institute).

How Do You Calculate the Total Living Area?

The Total Living Area is basically the sum of all the permitted, finished, conventionally heated space on a lot - and the key here is that it includes both above and below ground and connected or separate spaces. The measurement usually includes the external walls in the calculation.

Here are a couple of ways to determine the Total Living Area:

Option 1: Use an existing blueprint or floor plan

If you have an existing blueprint or floor plan for the building, you can import it into floor plan software like RoomSketcher. With RoomSketcher’s built-in area calculator, you can get your TLA  result in seconds - just click to exclude any unfinished, unheated, or open areas (like balconies) on the floor plan and then choose the “Gross Floor Area” calculation. See Calculate the Total Area of a Floor Plan for more information on RoomSketcher’s area calculations.

blueprint maker software

Option 2: Measure onsite

You can also measure up the property if you don’t have access to an existing floor plan. For example:

  1. Start with a walkaround - Walk around the property to get an idea of the shape and number of floors.
  2. Sketch the external walls on paper or tablet - Make a sketch of the property shape or create a digital sketch using floor plan software on your tablet. 
  3. Note the unfinished, unheated, or unenclosed space - Locate the areas or rooms that are unfinished or unheated spaces and mark these on your sketch. Also, note any unenclosed areas, like balconies, so you do not include them in the calculation.
  4. Get the measurements - Now, use a tape measure, roto wheel, or a laser to determine the size of any room or area that counts as finished space. It’s helpful to divide the areas into rectangles.  Once you’ve measured up one side of a rectangle, go ahead and measure the other direction. Remember to include the thickness of internal and external walls in your calculations.
  5. Do the math - Multiply the length and width of each rectangle to calculate its size. Add together all the rectangular areas on the floor while excluding any of the spaces you noted as unfinished on the floor plan. Repeat your calculations for all floors and buildings, and sum the result to calculate the property’s Total Living Area (TLA).

What Does Total Living Area (TLA) Include?

Total Living Area describes the total livable space on a lot or property, including finished and heated basements, attics, and adjacent, unconnected buildings. To be included in the calculation, each space must be:

What does total living area include

Top RoomSketcher Tip

*For a garage apartment to count in the TLA, in addition to being heated and lighted, the original vehicle access door must often be replaced or hidden behind finished drywall.

*Because standards vary slightly worldwide, check with your local authorities for a complete list of the standard inclusions in your area.

What is Excluded from a Total Living Area (TLA) Calculation?

Total Living Area describes the total living space. Thus, exclude areas that are:

Total living area exclusions

Top RoomSketcher Tip

Because standards vary slightly worldwide, check with your local authorities for a complete list of the standard exclusions in your area.

Total Living Area and Various Types of Residential Properties

When a property is an attached residence, such as a duplex or row house, you measure to the center of the connecting wall rather than include the entire external wall width.

TLA vs. Other Area Measurements

What is the difference between Total Living Area (TLA) and Gross Living Area (GLA)?

TLA includes all finished, heated, accessible spaces that are above or below grade, whether or not they are connected to the main house. In contrast, GLA only includes above-grade finished, heated spaces within the main house. GLA does not include basements (even finished ones) or separate buildings.

What is the difference between Total Living Area (TLA) and Gross Building Area (GBA)?

While Total Living Area is generally used for residential buildings, Gross Building Area can be used for both residential and industrial structures. 

TLA is focused on the total living space on a property. In contrast, GBA typically measures the entire building area, including areas unsuitable for living in, such as atriums, mechanical rooms, and elevator shafts in commercial buildings or shared interior stairways in multi-family residential buildings. GBA is also usually calculated and reported for a single building and does not include adjacent buildings.

What is the difference between Total Living Area (TLA) and Gross Internal Area (GIA)?

GIA is used for commercial buildings and includes the total internal floor space. Unlike TLA, GIA may include unfinished and unheated areas, like a manufacturing floor. While TLA generally includes the space occupied by external walls, GIA excludes exterior walls.

What is the difference between Total Living Area (TLA) and Total Square Footage?

Total Living Area describes the living space on a property and thus does not include unfinished and unheated areas. Total Square Footage, on the other hand, consists of every bit of the space and thus includes unfinished and unheated areas. Total Square Footage is helpful for construction estimates as builders need to understand the complete project.

TLA vs total Sq Ft

Frequently Asked Questions (FAQ's)

Improve Your TLA Measurement and Reporting Today

Total Living Area (TLA) is one of several important metrics in residential real estate. The RoomSketcher App allows you to turn your hand-drawn sketches into professional floor plans, perfect for real estate and appraisals. Plus, the App works on Windows and Mac computers and iPad and Android Tablets so that you can complete your work anywhere, anytime.

Please contact us if you want to discuss our services or ask questions about Total Living Area calculations; we would love to help you.

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