IPMS: update 2016

RICS property measurement: 6 months on

10 June 2016

Alexander Aronsohn, one of the team developing the International Property Measurement Standards, gives an update on progress


There have been a few milestones in the delivery of the International Property Measurement Standards (IPMS) since their launch in 2013. IPMS: Office Buildings was published in November 2014, followed by the launch of RICS property measurement 1st edition, the professional statement that incorporates IPMS in May 2015. The professional statement became mandatory for all RICS members measuring properties on 1 January 2016.

But what is the current situation in the property measurement standards series? Who is involved and what can we expect from this collaborative global effort?

The IPMS Coalition has continued to grow and there are more than 73 members committed to ensuring that property assets are measured in a consistent way, creating a more transparent marketplace, greater public trust, stronger investor confidence and increased market stability.


More than 200 partners including investors, corporate occupiers, property advisory firms and developers and representative organisations are committed, in principle, to IPMS

More than 200 partners including investors, corporate occupiers, property advisory firms and developers and representative organisations are committed, in principle, to IPMS. In recent months, many have gone a step further and require IPMS for all their measurement instructions to facilitate comparison, benchmarking and facilities management across their measurement portfolio. Since the RICS Property Measurement Professional Statement became mandatory, the UK government announced in its annual State of the estate that this has been adopted for its property portfolio, for example. Other early adopters include real estate firms, major car manufacturers and energy companies, which are instructing measurement professionals and other service providers to incorporate IPMS into all their instructions.

Residential buildings

This year we are making progress on the next building class in the series. IPMS: Residential Buildings is currently under development and incorporates revisions and improvements from IPMS: Office Buildings to ensure that it is fit for purpose, i.e. used to measure residential property. The IPMS Standards Setting Committee (SSC) is a team of international experts who believe that setting standards is a continual process. It is committed to incorporating comments from the consultation to ensure that the IPMS meets market needs for all building classes.

The SSC has revised the definitions for both internal dominant face (IDF) and vertical section, because many consultation respondents commented that they found these confusing. Although these terms still mean the same, IDF has been defined as: "The inside finished surface comprising more than 50% of the floor-to-ceiling height for each IDF wall portion. If such does not occur, then the finished surface is deemed to be the IDF."

Vertical section has also been renamed as IDF (wall portion) and redefined as: "Each internal finish of a portion of an external wall, ignoring the existence of any columns, that is either recessed from or protrudes from its adjacent portion." The SSC hopes that these revisions make it easier for non-native English speakers to interpret and apply the IPMS-recommended practices.

IPMS Residential

Figure 1: IPMS Residential Buildings incorporates a new definition for a balcony

IPMS: Residential Buildings also incorporates new residential definitions.

  • Balcony: An external platform at an upper floor level with a balustrade to the open sides projecting or recessed from an external wall and including generally accessible rooftop terraces, external galleries and loggia.
  • Mezzanine: An intermediate or partial storey, other than a catwalk, between the floor levels or roof of a building, and usually fully or partially open on 1 or more sides.
  • Patio: A paved or floored terrace, adjacent to a building, which may be covered by an independent framework.
  • Veranda: An open or partly enclosed area on the outside of a building at ground level (Level 0), and covered by a roof that is an integral part of the building.

Users of IPMS: Residential Buildings will also note a number of changes to the format of the standards and in addition to:

  • Part 1 – Aim and scope of the standards,
  • Part 2 – Principles of measurement
  • IPMS 2 and Part 3 – IPMS standards,
  • Part 4 – Technical section, which contains the IPMS Residential Component Areas and the IDF technical diagrams.

In response to comments from stakeholders, the SSC felt that it was a mistake to have a direct link only between IPMS 2 and component areas. It also felt that the standards and the methodology used to measure the standards, although interlinked, should stand separately.

IPMS Residential Component Area B has now been revised to include the following 3 sub-categories:

  1. IPMS Residential Component Area B1, external walls, defined as: "The external enclosure of a building, which comprises the area between the IDF and the outside face of the building."
  2. IPMS Residential Component Area B2, internal structural elements comprising all internal structural walls and columns.
  3. IPMS Residential Component Area B3, Internal non-structural elements, comprising all internal full height permanent walls other than those included in Component Areas B1 and B2.

Component areas

One of the main advantages of these revisions is that, apart from providing greater clarity for the end user, it is now possible to calculate IPMS 1 via the sum of all the component areas and IPMS 2, by taking the sum of all component areas less IPMS B1 the external walls. These revisions provide a vital link to IPMS 1 and IPMS 2 and allow end users and measurement practitioners to cross-check by totalling the relevant component areas.

Regarding IPMS 1, IPMS 2 and IPMS 3, the following definitions for the IPMS Residential Buildings incorporate the principles in IPMS: Office Buildings:

  • IPMS 1: In some markets, this can be used by parties for planning purposes or the summary costing of development proposals. It is defined as: "The sum of the areas of each floor level of a building measured to the outer perimeter of external construction features. It is the same for all classes of building. In many markets, but not universally, this is known as gross external area."
  • IPMS 2: This will assist the property industry to make efficient use of space and benchmarking data, and is defined as: "The sum of the areas of each floor level of a residential building measured to the IDF. In many markets, but not universally, this is similar to gross internal area."
  • IPMS 3: This is for measuring the occupation of floor areas in exclusive use and is defined as: the floor area available on an exclusive basis to an occupier".

However, in respect of IPMS 3, the SSC has researched international markets and due to the diverse nature of residential property (e.g. apartments, houses, duplexes) has identified 3 different measurement bases for areas in exclusive use that need to be accommodated.

IPMS 3A: The area in exclusive occupation measured to:

Detached dwellings

  • the outer face of the external wall.

Attached dwellings

  • the outer face of the external wall
  • the centre line of shared walls between occupants.

Multi-unit dwellings

  • the outer face of the external wall
  • the centre line of shared walls between occupants
  • the finished surface of walls shared with common facilities.

IPMS 3B: The area in exclusive occupation, including the floor area occupied by internal walls and columns, measured to:

  • the IDF
  • the finished surface of internal perimeter walls.

IPMS 3C: The area in exclusive occupation, excluding the floor area occupied by full-height internal walls and columns, measured to:

  • the IDF
  • the finished surface of all full-height internal walls.

Some markets require only one IPMS 3 measurement base, but others may use 2 or more for different purposes.

Alexander Aronsohn FRICS is RICS Director of Technical International Standards and Executive Secretary of the IPMS SSC

Further information

  • Related competencies include Measurement
  • This feature was taken from the RICS Property journal (May/June 2016)