Take the Heathrow Express train to Paddington. From there either take a taxi straight to Club Quarters, St. Paul's or take the District or Circle Line (Green/Yellow) on the underground to Blackfriars. Exit the underground station and walk up New Bridge Street away from the river, staying on the right hand side of the street. On reaching Ludgate Circus, turn right onto Ludgate Hill and walk up the hill towards St Pauls Cathedral. You will find Club Quarters on the left hand side of the street at the top of the Hill just before the Cathedral.
Alternatively, take the Piccadilly Line (Blue) on the underground to Holborn Station where you would change to the Central Line (Red) to St. Paul's. You need to take the St. Paul's Cathedral exit, go through St. Paul's Churchyard, staying to the right side of the Cathedral. Once you are at the front of the Cathedral, Club Quarters will be on your right hand side when you look down Ludgate Hill.
Journey will take approximately 45 minutes and cost approximately £5.30. You can purchase your transportation ticket at the underground station at Heathrow.
To reach Club Quarters St. Paul’s from Gatwick Airport you have 2 choices:
Take the Gatwick Express train to Victoria Station where you can either take a taxi straight to Club Quarters, St. Paul's or change to the District/Circle Line (Yellow/Green) on the underground to Mansion House. Take exit No. 3 - Cannon Street (West), and take the right hand side stair exit onto Cannon Street. Walking straight ahead at all times and facing the rear of St. Paul's Cathedral, a 5 minute walk will bring you to the front of the Cathedral, which faces down Ludgate Hill. Club Quarters is at the top of Ludgate Hill on the right hand side as you look down Ludgate Hill.
Club Quarters is affiliated with the Baynard House Car Park at 133 Queen Victoria Street. The car park is a 10-15 minute walk from Club Quarters. The cost is £2.50 per hour Monday through Friday 6.00am - 7.00pm, Saturday 6.00am - 1:30pm, Sunday and all other times £2.50 per visit per day - including overnight stays.
http://en.parkopedia.co.uk/parking/carpark/baynard_house/ec4v/london/