My daughter is first year this year and started at 16. With majority of year group being under 18 at start of year, is definitely a limit to options. Quite a number are at Friendship House, there is also a group at IQ Paris Gardens. These were the only options close by we found for under 18.
Others are either at home or in home stay accommodation.
Whilst Friendship and IQ try to keep the CBS students on same floor, in reality some are split across floors due to late bookings etc. IQ only take students, where as Friendship has different requirements. Both have a policy for CBS students under 18, so do advise they are CBS student when you discuss booking