Question: The event that caused Sir Christopher Wren to design a new cathedral consumed how many houses?

Context paragraphs:
St Paul's Cathedral: St Paul's Cathedral, London, is an Anglican cathedral, the seat of the Bishop of London and the mother church of the Diocese of London.  It sits on Ludgate Hill at the highest point of the City of London and is a Grade 1 listed building.  Its dedication to Paul the Apostle dates back to the original church on this site, founded in AD 604.  The present cathedral, dating from the late 17th century, was designed in the English Baroque style by Sir Christopher Wren.  Its construction, completed in Wren's lifetime, was part of a major rebuilding programme in the City after the Great Fire of London.

Great Fire of London: The Great Fire of London was a major conflagration that swept through the central parts of the English city of London from Sunday, 2 September to Wednesday, 5 September 1666.  The fire gutted the medieval City of London inside the old Roman city wall.  It threatened but did not reach the aristocratic district of Westminster, Charles II's Palace of Whitehall, and most of the suburban slums.  It consumed 13,200 houses, 87 parish churches, St Paul's Cathedral, and most of the buildings of the City authorities.  It is estimated to have destroyed the homes of 70,000 of the City's 80,000 inhabitants.

William Talman (architect): William Talman (1650–1719) was an English architect and landscape designer.  A pupil of Sir Christopher Wren, in 1678 he and Thomas Apprice gained the office of King's Waiter in the Port of London (perhaps through his patron Henry Hyde, 2nd Earl of Clarendon).  From May 1689 until William III's death in 1702 he was Comptroller of the Royal Works, and also in 1689 William Bentinck, 1st Earl of Portland appointed Talman and George London as his deputies in his new role as Superintendent of the Royal Gardens.  In these roles Talman worked with Wren in his rebuilding of Hampton Court Palace and its gardens and, by proposing a cheaper interior decoration scheme for the new building, won that commission over Wren's head.

Christ Church Greyfriars: Christ Church Greyfriars, also known as Christ Church Newgate Street, was a church in Newgate Street, opposite St Paul's Cathedral in the City of London.  Established as a monastic church in the thirteenth century, it became a parish church after the dissolution of the monastery.  Following its destruction in the Great Fire of London of 1666, it was rebuilt to the designs of Sir Christopher Wren.  Except for the tower, the church was largely destroyed by bombing during the Second World War.  The ruins are now a public garden.

Christopher Wren, Jr.: Christopher Wren (1675–1747), was a Member of Parliament and the son of the architect Sir Christopher Wren.

Henry Godolphin: Henry Godolphin (1648–1733) was a Provost of Eton College and Dean of St. Paul's Cathedral in London, a position in which he clashed with Sir Christopher Wren in the period when the new cathedral had reached the finishing touches.

St Bride's Church: St Bride's Church is a church in the City of London, England.  The building's most recent incarnation was designed by Sir Christopher Wren in 1672 in Fleet Street in the City of London, though Wren's original building was largely gutted by fire during the London Blitz in 1940.  Due to its location in Fleet Street, it has a long association with journalists and newspapers.  The church is a distinctive sight on London's skyline and is clearly visible from a number of locations.  Standing 226 feet (69m) high, it is the second tallest of all Wren's churches, with only St Paul's itself having a higher pinnacle.

Wren Hall: Wren Hall is a Grade I listed building in Salisbury Cathedral Close, Wiltshire.  Situated on the west side of Choristers' Green it was originally part of the attached Braybrook House.  A rebuilding was commissioned and funded by Sir Stephen Fox, an alumnus of the Cathedral School, and carried out in 1714 by Thomas Naish, Clerk of Works to the Cathedral to provide a classroom and further dormitories for the cathedral choristers.  It has little proven connection with Christopher Wren except that in its style it provides a suitable memorial to that great Wiltshire born architect.  After the removal of the Choir School the College of Sarum St Michael acquired it for a short period until it became the diocesan archive repository.  In the 1980`s it was used as the Salisbury Cathedral Spire Appeal office and in the past few years has become a Cathedral educational resource centre for school visits.  The desks of the headmaster and assistant master remain at opposite ends of the room as a reminder of the original use as a single large classroom, or “Big School Room” as it was called, with the two classes sitting back to back.  The attic contains some dormitories and there are original medieval cellars below the building.

Winslow Hall: Winslow Hall is a country house, now in the center of the small town of Winslow, Buckinghamshire, England, built in 1700; it was sited in the centre of the town, with a public front facing the highway and a garden front that still commanded 22 acre in 2007, due to William Lowndes' gradual purchase of a block of adjacent houses and gardens from 1693 onwards.  The architect of the mansion has been a matter of prolonged architectural debate: the present candidates are Sir Christopher Wren or a draughtsman, whether in the Board of Works, which Wren oversaw, or a talented provincial architect.

The Old Court House: The Old Court House is an 18th-century Grade II* listed house located off Hampton Court Green in Richmond upon Thames in south west London whose origins date back to 1536.  The architect Sir Christopher Wren, who lived there from 1708 to 1723, was given a 50-year lease on the property by Queen Anne in lieu of overdue payments for his work on St Paul's Cathedral.  The lease passed from Wren's son to his grandson.  It was purchased from the Crown Estate in 1984.

Supporting paragraphs: Christ Church Greyfriars Great Fire of London
Answer: 13,200