The Brigade has developed a new system of ranking house fires as severe, significant, moderate or slight.
A fire is classed as severe it if renders a property uninhabitable for any period of time.
Over the past year 2,257 fires, a third of all house fires, were severe.
Officials estimate providing temporary accommodation and repairing damaged properties costs London £120 million each year.
Cllr Susan Hall, Chairman of the London Fire and Emergency Planning Authority’s Community Safety Committee, said: “At a time when London is facing a major shortage in housing, it is shocking to know that so many homes are being lost to fire each year. Sadly, most of these fires are entirely preventable.
“Many people think that a fire will never happen to them but these figures show that it’s not worth taking the risk. Fires can, and do, cost people their entire homes and everything in them.
“If you love your home, get a working smoke alarm, never leave cooking unattended and switch off all electrical appliances when you’re not using them.”
