Every commercial property in the UK is required to fall under a specific use class, defining what the property can be used for and meeting rooms are exactly the same. Most meeting rooms available to hire would fall under the use class of B1, D1 or D2.
The use class of D1 is defined as Non-Residential Institutions, which basically describes dwellings that are not for residential use and is wholly suitable for meeting rooms.
The D2 use class is defined as Assembly and Leisure and again in some cases would be applicable for a large meeting room, although it is more typically assigned to larger sports halls or leisure facilities and clubs.
The use class of any meeting room you hire should have no effect on your meeting, and is really only applicable to anyone wishing to, for example, purchase and convert either a residential or commercial property into a meeting room venue, or build new meeting rooms independetly or attached to an existing property.
Booking a Meeting Room