Fact-checking the London Plan home building debate: Who really decides where we build?

Hillingdon Council warns that the Mayor’s Draft London Plan will “force” 24,030 new homes onto the borough over 10 years, with 61% on Green Belt land – the highest share of any London borough.  Both figures are accurate.  But the council’s own explanation of how this system works doesn’t match the alarm it’s raising.

Who actually decides where the homes go?

The London Plan sets each borough an overall housing figure.  Where Green Belt release is needed, it points to broad zones – for Hillingdon, Green Belt land within walking distance of six stations: Hillingdon, Ickenham, Northolt, Ruislip Gardens, South Ruislip and Uxbridge.  (Northolt station sits just over the border in Ealing, but its catchment reaches into Hillingdon’s Green Belt.)

What the London Plan does not do is draw actual boundaries or name specific fields.  That decision belongs entirely to the council, through its own Local Plan.

This was confirmed directly by Gavin Polkinghorn, one of Hillingdon’s planning officers at the Corporate Resources & Infrastructure Select Committee on 29 July.  When asked by Cllr Jonathan Bianco about the council’s power to control specific sites, the officer was clear: the London Plan sets the targets, but “that’s up for us to set” when it comes to exactly where the homes go.

Cllr Riley Russell, whose name appears on Conservative party campaign emails claiming City Hall is forcing the locations, was also in the room to hear that explanation. 

Is Hillingdon being uniquely burdened?

Cllr Tuckwell says there is “no evidence to justify placing such a disproportionate burden on Hillingdon.”
The data suggests otherwise.

• No – other outer boroughs face the same rate.
  Hillingdon’s large total mostly reflects that it’s London’s second-largest borough, with more land, more Green Belt, and more well-connected stations than most – giving it far more room to spread the number across.  Measured fairly, as homes required per hectare of Green Belt held, Hillingdon (3.03), Barnet (2.94) and Harrow (2.90) are all asked to build at almost the same rate. 

• No – several inner boroughs are asked to build even more, with no Green Belt at all.
  Southwark (27,799), Wandsworth (26,609) and Newham (26,260) all have targets equal to or higher than Hillingdon’s – and every home in those targets must come from brownfield land, because inner London boroughs have no Green Belt to draw on.

The contradiction

Cllr Steve Tuckwell, Leader of Hillingdon Council, said the Mayor is “trying to dictate Hillingdon’s future from City Hall” – a claim published on 30 July, the day after the council’s own planning officer told a public committee the opposite: it’s the council, not the Mayor, that decides where in Hillingdon any new homes go.

The council’s numbers are correct.  Cllr Tuckwell’s claim that City Hall is imposing site-specific decisions is not, by the council’s own evidence.

Have your say

The Mayor’s Draft London Plan consultation is open until 15 October 2026.

Hillingdon’s own Local Plan consultation closes sooner, on 21 August 2026 – but this is only the first, “scoping” stage, asking what the plan should generally contain.

A second stage, on proposed content and evidence, follows this year (closing 5 November 2026).  The stage where specific Green Belt sites and boundaries are actually proposed for comment isn’t due until around June 2027.

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