Yesterday's news about the latest census was not that there are 1.5 million people with second homes. There are 1.5 million people with second addresses:

"More than 1.5 million people said they had a second address in England and Wales (2.8% of the population), of which 189,000 were working addresses, 165,000 were holiday homes and 1.2m were classed as "other", which included students' home addresses and a second address for children of separated parents."

(The Guardian - http://www.guardian.co.uk/money/2012/oct...NTCMP=SRCH)

I was surprised there are 'only' 165,000 holiday homes but I suppose their concentration in some areas puts pressure on the supply of local housing stock, creating a local problem rather than a national one. I doubt we have many holiday homes in SE London.