IPMS 3 uses the term ‘useable floor area’ meaning space for the exclusive use of an occupier.
IPMS 3 reports on:
• Useable floor area (previously NIA)
• Limited floor area (additional areas that need measuring, but don't make up any of the useable floor area used for rent calculation) and
• Office total (total of limited use area plus useable floor area)
Examples of limited floor area that must now be measured include balconies/rooftop terraces, internal structural walls, columns, common walls, walkways, shared circulation areas and areas less than 1.5m in height.
IPMS is mandatory for RICS qualified chartered surveyors, but as a landlord, you can ‘opt out’ as long as you give a valid reason to your instructing agent in writing.
Whilst the rentalised area shouldn't increase with IPMS 3 because the useable floor area calculations are similar to NIA, I would recommend taking early specialist advice so as to avoid confusion over inclusions and exclusions from floor area calculations.