The introduction of the RICS Code of Measuring ensures methodological consistency, enhancing numerous areas within the real estate industry.


Gross Internal Area (GIA) is a professional and widely-accepted method of measuring the full internal area of a building, as defined by the Royal Institution of Chartered Surveyors. This measurement includes all areas inside the external walls such as stairwells, lift shafts, and internal partition walls. However, it excludes external open areas like yards or gardens. Whether you're looking at office buildings, retail spaces, or industrial properties, understanding your GIA is crucial for effective space management and lease planning.

Just as Gross Internal Area (GIA) is important, Net Internal Area (NIA) is another key measure that property professionals often use. The NIA refers to the usable area within a building, essentially it's the GIA minus the floor areas taken up by structural walls, stairwells, lift shafts, and other spaces that cannot be occupied. In the context of lease planning, the NIA helps to determine the actual area that a tenant can use for their business operations. While GIA gives the total spatial volume of a building, NIA gives a more accurate picture of a functional space, making it a critical aspect to consider in property leasing and management.

Another critical metric in property management is the Gross External Area (GEA). The GEA refers to the total area of a building, including the thickness of the external walls and any external projections such as balconies or fire escapes. Essentially, it measures the total footprint of a building, providing insights into the whole extent of a property. Understanding the GEA is particularly vital for assessing a property's impact on its surroundings or determining the property's total volume for construction or regulatory purposes. Therefore, along with GIA and NIA, the GEA is an additional factor that property professionals and tenants should consider when managing spaces or planning leases.