In February there was an announcement that Transport for London was looking at selling some of its land to raise money for improving the transport network in the capital.

That is welcome. TfL estimates that it owns 5,700 acres.

But astonishingly it doesn’t really know.

They tell me in response to an FOI request:

“There are estimated to be some 350 acres owned but not yet registered with TfL. The actual figure will be confirmed later this year.”

They do offer this breakdown of the land they have already established that they own:

Crossrail 73 acres

Docklands Light Railway 107 acres

London Buses 123 acres

London River Services 3 acres

London Underground 2,499 acres

Rail For London 72 acres

Transport for London 2,467 acres

Transport Trading Ltd 2 acres

Total 5,345

However the breakdown I had asked for was different:

Please provide an approximate breakdown of the 5,700 acres including an indication of the number of acres taken up with:

1. Roads.

2. Tracks.

3. Stations.

4. TfL offices.

5. Commercially leased buildings (such as shops).

6. Land – with any information as to whether the land is currently used for anything.

But they don’t know:

“We do not hold the information in the form that you are requesting. We do record freehold land by company ownership, but this does not distinguish between uses, e.g. tracks versus stations.”

So of the 5,700 acres (assuming it is 5,700 acres) we simply don’t know how many are surplus to requirements. A tenth? A fifth? A quarter? A third? Half?

The answer matters. The whole of Camden is 5,384 acres, Hammersmith and Fulham is 4,238. Kensington and Chelsea is 3,059.

Camden has 102,703 homes. That’s 19 an acre. So if TfL found that half their land could be made available for housing that would be more than 50,000 new homes. It could be more, of course. In Kensington and Chelsea people squash up a bit more with all those mansion blocks – there are 26 homes an acre.

The average price of a new home in London is £514,000. Let us suppose (rather conservatively I think) that the value of the land makes up half the value of each property. Let us also (rather conservatively) take the Camden figure of 19 homes an acre. So that would mean TfL could raise £12.5 billion from selling land for housing. Thus both easing the housing supply and making it much easier to get significant extra funds for transport improvements. Perhaps only a quarter of their land could be sold. Perhaps three quarters. Perhaps TfL’s figure of £3.4 billion in proceeds really is the most that is possible.

My point is a simple one. We don’t know. It would be helpful to find out. Their asset management is quite staggeringly lax. Until it is sorted out, let us hear no more pleading from TfL about how it is “vital” to have a subsidy from taxpayers (including those far away from London) or “essential” to have a fares increase to pay for this or that infrastructure project.