When meeting in person, we have in the past used Highfield Church Centre, Highfield Lane, Southampton, SO17 1RL.
Highfield Church Centre is on Highfield Lane, and is adjacent to Highfield Church, which is on the corner of the junction of Highfield Lane and Church Lane. The centre is within easy walking distance of local bus stops on Portswood High Street, and is a ten minute walk from St Denys train station. If you are travelling to Southampton Central or Parkway train station, you can take a Unilink bus (U1A or U1C, respectively) from the train station to Portswood High Street, which is just a few minutes walk from the Highfield Church Centre. There is limited parking on site, with plenty of free on street parking available nearby.