No legislation ( why would there be-The Organisation Of Meetings In Offices Act 1984 Section 12 “when to provide coffee and biscuits- referencing the right guaranteed by the Article 12 of the European Convention on Human Rights  on tea and coffee at work”!)

And yes it requires that common sense thing – a risk assessment based approach.

Questions to ask include:

1. What sort of meetings- a short bird table type meetings can be held in broom closet while and all-day doing “work streams” and “setting up  workshops”  requires more space.
2. Breakout rooms or time-tabled meetings
3. The sort of people- any people with mobility issues or visually impaired or hard of hearing.
4. The culture of the place? - how informal are the chats or are they lectures or round table meetings.
5. How much IT and Audio-visual gubbins in the rooms
6.  How much space can the organisation afford to surrender
7. Appetite for IT based solutions- so you stay at your desk to have the meeting. Not always good for you back etc. Getting an opportunity to move around even if it is to go to a meeting can be beneficial

There’s more but this will do for a start

ADB suggests that 1cubic metre per person is the required space in these area

SBH

 anne, all the meeting rooms in my workplace have signs on indicating the maximum occupancy. Aparently these were done by several "competent persons ". There seems to be a lot of variation in the numbers allowed based on the layout and access points and the type of furniture in it., I have reviewed a couple and come up with some credible numbers and layouts.

I used a RA picked up on NEBOSH Fire certificate which works beutifully for this , I will dig it out and forward if you still need it next week. as I am not in office at moment.

 Basically you are on the right track with access/egress if you need to evacuate as a guiding prinicple and keep furniture to a minimum- don't let meeting rooms become repositries for furniture! 

Nic