Why is affordable housing in London a big deal?

London is already one of the least affordable cities in the UK own a property, and house prices and rents are soaring.

The issue is likely to be a big deal in the London mayoral election on 5 May.

Conservative hopeful Zac Goldsmith has said lack of affordable homes is “the number one issue for London” while Labour’s candidate Sadiq Khan has said solving the housing crisis will be “at the heart of my mayoralty”.

Whoever wins the election will inherit housing deals made by the outgoing mayor, Boris Johnson, who claims to have delivered more affordable housing than his Labour predecessor, Ken Livingstone.

What is affordable housing?

Confusingly, the category used to cover three types of dwelling: social rent, affordable rented and intermediate housing.

“Social rented” properties are usually managed by councils or housing associations and let at low rents to those deemed to be most in need.

“Affordable rented” means the rent is capped at up to 80 per cent of local market rents – which obviously may not be truly affordable to many people.

The government recently decided to change the definition of affordable housing to include “starter homes” on sale for to £450,000 in London.

LONDON, ENGLAND - NOVEMBER 25: Boris Johnson, the Mayor of London, prepares to pour concrete from a skip suspended from a crane at the construction site of the 'Greenwich Square' housing development on November 25, 2013 in London, England. Mr Johnson assisted the residential building work, approximately half of which will be low-cost rent or buy accommodation, as he launched his new draft Housing Strategy for the capital. The Mayor aims to address issues around London's rapidly increasing housing needs and in particular the provision of low cost housing. (Photo by Oli Scarff/Getty Images)

What is Boris Johnson’s record?

Boris says he is on course to oversee the construction of 100,000 affordable homes over his two terms as Mayor of London.

His office told us they were at about 98,000 now and were on course to complete the rest before the end of Boris’s second term in May.

GLA figures suggest he failed to meet another target to deliver 55,000 affordable homes between April 2011 and March 2015 – by about 4,000 dwellings.

The same figures suggested that the number of affordable homes being built slumping to a just a few thousand in 2015/16, although figures for the full year are obviously not available yet.

In Boris’s defence, 100,000 affordable homes over his eight years in power is better than the number achieved by Ken Livingstone in the previous eight years.

On the other hand, demand for affordable housing is higher than what is currently being delivered.

Boris’s own Strategic Housing Market Assessment says the capital needs 48,800 homes a year over 20 years, with about 25,000 a year “affordable”, and tens of thousands more homes than this needed to make up for years of under-supply.

Over the last eight years of Boris’s time in office, the percentage of affordable homes built that fall into the “social rent” category – that’s the housing most accessible to the lowest earners – has fallen sharply:

What is Channel 4 News saying about sales of public land in London?

The programme is broadcasting an investigation tonight into how many homes being built on public land sold by the GLA to developers since 2012 are affordable.

The list of 35 sites around the capital covers former hospital and school sites, a former greyhound stadium in Catford and land in Docklands and the Greenwich Peninsula.

The researchers say only a quarter (26 per cent) of housing due to be built on plots sold during Boris’s most recent term as Mayor is affordable.

The GLA disputes this, saying the real proportion is 31 per cent. The difference boils down to which developments you include.

Channel 4 News has decided not to include joint ventures, deals that have not yet been signed off and affordable housing figures based on future reviews, in order to get a fair snapshot of what has been achieved during Boris’s second term.

The GLA says you should include more sites on a longer list, giving a higher percentage of affordable housing.

Both versions can be viewed here. The original GLA left is on the left and the Channel 4 News version, with amendments and exclusions, is on the right.

Whichever figure you prefer, Boris cannot be accused of missing a target on affordable housing – because he doesn’t have one.

His predecessor as Mayor, Ken Livingstone, pledged to make 50 per cent of all new developments affordable, but fell well short of that aspiration.

Boris scrapped the London-wide 50 per cent target, saying it was “inflexible” and would hinder development.

London’s boroughs tend to have their own affordable housing targets of between 35 and 50 per cent, although the Financial Times reported last year that most were missing those benchmarks too.

Sadiq Khan has pledged to revive the promise to make half of all development affordable if elected.

The GLA also says the public land it is selling will deliver about 50,000 homes as well as parks, schools and other amenities, after laying dormant for years.

What’s happening outside London?

There is a nationwide drive to sell public land for housing, but the National Audit Office said in a report that poor record-keeping made it hard to say whether the taxpayer was getting value for money.

The NAO said government departments “do not routinely monitor what happens to a site after disposal so there is no information on how many homes have been built on sold land”.

And the Department for Communities and Local Government “does not collect information on the amount of money raised from the sales”.

“Without data on the number of homes or sales proceeds, it is difficult to assess if departments obtained good value from their disposals and, more broadly, if government secured value for money from the programme as a whole.”

As in London, the percentage of affordable homes built that are earmarked for social rent have been falling sharply across England.