You have to have meeting rooms. People always say you don't, but you always do. Where do you do sprint planning? Project brainstorming? Private meetings (with actual privacy needed, like reviews)?
No dedicated meeting room? Yes, meetings should be reduced to an absolute minimum and can be held in one of the offices or in the stand-up area. This makes them public and everyone easily has the chance to join in. The same is true for client meetings, which in my experience rarely take place at the office if you are an agency, anyway. So, no dedicated meeting rooms necessary.
Sprint planning: in the town hall if the sprint involves most of the team, or in on of the offices. A three people office can accommodate a small sprint team of 6-7 people.
Project brainstorming: In the town-hall, in the kitchen, maybe outside when taking a walk?
Private meetings: In most cases, the privacy of the corner seating areas will be enough, but I think most of the times at least small office will be vacant, because not everybody is in the office all the time.
