You would think that measuring a property would be easy, however, when it comes to getting you a refund on your business rates, you don’t want to get it wrong and it’s more complex than you may initially think. This is where Hampton Lovett come in.

Hampton Lovett will carefully survey your business premises to find out if you have been overpaying on your business rates. Not only will we look at the net internal area, but we will also consider the gross internal area. We will consider what zone your business premises has and should be categorised as. We will assess your business premises in its entirety and if there is something that we can use to challenge the VOA to make an adjustment then that’s exactly what we’ll do.



Zoning is a standard method of valuing and comparing retail premises. Shops or retail premises are divided into zones, starting from the window. Typically, each zone has a depth of 6.1 metres although this can vary depending on the location of the property. Zones become less valuable the further they are from the window/entrance. Zone A, which is the closest, is the most valuable as it has the highest potential to generate business for the shop. Zone B is next, then Zone C. Anything after Zone C is usually defined as the remainder.


The VOA uses standard measuring methods based on the Royal Institution of Chartered Surveyors (RICS) former code of measuring practices.

There are two common methods -

The net internal area (NIA) method of measurement is one and is generally applied to:

• Offices

• Shops

• Other retail premises, such as banks, hairdressers, restaurants

The gross internal area (GIA) method of measurement is generally applied to industrial property such as warehouses or manufacturing units.


It costs nothing to find out if we can help your business claim back thousands of pounds as a result of an incorrect Rateable Value being applied to your property.

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Net Internal Area

The net internal area (NIA) is the total usable area of each floor within a building, measured to the inside face of the boundary walls (ignoring skirting boards).


Areas measured include:

  • Kitchens
  • Any built-in cupboards or units
  • Perimeter skirting boards, mouldings and trunking
  • Open circulation areas such as atria, corridors, and entrance halls
  • Partition walls and other dividing elements


Areas that are excluded are:

  • Internal structural walls
  • Walls (whether structural or not) enclosing excluded areas
  • Piers, columns, chimney breasts, ducts, and other projections
  • Cleaner’s cupboards
  • Lifts, lift rooms, lift wells
  • Stairwells and landings
  • Stairwells, entrance halls, atria, landings, and balconies used in common or for essential access
  • Corridors and other circulation areas used in common with other occupiers or of a permanent essential nature
  • Boiler rooms, fuel stores, plant rooms and tank rooms other than those of a trade process nature
  • Car parking areas
  • Spaces occupied by cooling and heating equipment, air conditioning systems and ducting which renders the space substantially unusable
  • Areas with a headroom of less than 1.5m
  • Toilets and associated lobbies, unless additional toilets have been installed
  • Areas under the control of service or other external authorities

Gross Internal Area

This is the area of a building that’s measured to the internal face of the external walls at each floor level, which includes:

  • Areas occupied by internal walls and partitions
  • Columns, piers chimney breasts, stairwells, lift-wells, other internal projections, vertical ducts
  • Atria and entrance halls with clear height above, measured at base level only
  • Internal open-sided balconies, walkways
  • Structural, raked, or stepped floors are treated as a level floor, measured horizontally
  • Horizontal floors with permanent access below structural, raked, or stepped floors
  • Corridors of a permanent essential nature (such as fire corridors and smoke lobbies)
  • Areas in the roof space intended for use with permanent access
  • Mezzanine areas intended for use with permanent access
  • Lift rooms, plant rooms, fuel stores and tank rooms which are housed in a covered structure of a permanent nature, whether above the main roof level or not
  • Service accommodation such as toilets, toilet lobbies, bathrooms, showers, changing rooms, cleaners’ rooms
  • Projection rooms
  • Voids over stairwells and lift shafts on upper floors
  • Loading bays
  • Areas with a headroom of less than 1.5m
  • Pavement vaults
  • Garages
  • Conservatories


The Gross Internal Area method excludes:

  • Perimeter wall thickness and external projections
  • External open-sided balconies, covered ways and fire escapes
  • Canopies
  • Voids over or under structural, raked, or stepped floors
  • Greenhouses, garden stores, fuel stores and the like in residential property
  • Open ground floors
Leasing (2)

Adjustments and end adjustments

In certain circumstances, the VOA may make adjustments to recognise a disadvantage or advantage in the property (or parts of it) compared to other broadly similar properties.

For example, an air-conditioned office might have an adjusted value if other local offices don’t. The adjustment may be on part of the assessment or the whole (as an end adjustment).


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