London's Grey Belt Plan 2026: What It Means for Developers

There's been quite the stir in planning circles (and political ones too) since Sadiq Khan first revealed plans to build new homes on sections of London's Green Belt. Well, the talking is over - on 16th July 2026, City Hall published the actual draft London Plan, and the "Grey Belt" has gone from a phrase politicians liked to say in speeches to a named list of sites you can check against a map.

Let's unpack what's actually in it, and what it means for developers.

Key Highlights

• The draft London Plan was published on 16 July 2026 and is open for public consultation until 15 October 2026.
• It sets a target of 558,000 new homes by 2037.
• It names 10 "Broad Locations for Growth" for residential-led green belt release, plus 9 for industrial use.
• Affordable housing requirements are shifting from a single London-wide rule to thresholds set borough by borough.
• If adopted, the plan would start shaping planning decisions from 2028 - so this is a marker for the future, not an overnight change.
  
  
  
  
•  

What Did Sadiq Actually Say?

Back when he first launched the policy shift, Khan pledged to review low quality Green Belt land for development. His argument? Some parts of the Green Belt are not green, not open, not accessible, and provide very little biodiversity benefit. We're talking about underused scrubland, abandoned petrol stations, disused car parks… sites with little ecological value but plenty of development potential, at a time when thousands of Londoners are on housing waiting lists.

To be clear, he was never suggesting a free for all. And now we can see exactly what he meant: the draft plan sets out 10 named "Broad Locations for Growth" (BLGs) within the green belt, earmarked specifically because they have decent transport links and existing infrastructure - the idea being that scattered, ad hoc releases tend to produce low-density development in the wrong places, whereas focusing on well-connected sites actually shifts the needle on housing numbers.

The 10 Broad Locations for Growth (Green Belt, Residential-Led Mixed Use):

1. Croydon - New Addington
2. Eastern Hainault Loop
3. East of Ickenham
4. Mill Hill and Barnet
5. Northwood
6. Crews Hill and Chase Park
7. Upminster
8. Harold Park
9. West Ruislip
10. Dagenham

A further nine locations have been earmarked for industrial-led green belt release. Not every borough is on board, mind - some of these allocations remain contested locally, so don't take the list as a done deal just yet.

Sources:

📰 Building Design - The Draft London Plan Beyond the Headlines

📰 The Planner - Green Belt No Longer Off-Limits in New London Plan

A Green Belt History Refresher

The Green Belt was created to prevent urban sprawl and to protect the countryside. Noble intentions, yes - but the planning map hasn't exactly kept pace with modern needs. Some sites designated as "protected" decades ago are now sitting next to busy A-roads or surrounded by development on all sides. It's hard to justify keeping them locked away when Londoners are struggling to find homes they can actually afford.

Still, it's a politically sensitive subject. We've already seen spirited opposition, and at least one council (Enfield, on the Crews Hill and Chase Park site) has pulled its support since the draft was published.

Enter the Grey Belt - And Why It Matters

At LandTech, we’ve been talking about the Grey Belt for a while. Our platform helps identify these often overlooked sites - places that might be technically in the Green Belt, but that are primed for smart, sustainable development.

This is a moment for the industry. A more pragmatic approach to planning could open up land that’s just been sitting there, contributing neither to housing supply nor biodiversity. For developers, it’s an opportunity to rethink what’s possible - and where.

Want to see where this land might be hiding? Our Grey Belt data can help you cut through the noise and spot the opportunities.

What This Means for Planning Policy

This isn't just a change in tone - it's a genuinely more prescriptive approach from City Hall. Rather than defending every inch of Green Belt on principle, or leaving grey belt release to be argued out site by site, the draft plan sets a strategic list and asks boroughs to work within it.

We're now seeing:

• A named shortlist of green belt sites prioritised for release, rather than a vague direction of travel
• Affordable housing thresholds moving from one London-wide rule to borough-specific tiers
• A clear, if lengthy, timeline: consultation until 15th October 2026, followed by examination, with adoption pencilled in for 2028

Of course, a draft plan and an adopted plan are different things. Consultation responses could still reshape the detail, and 288 pages of policy rarely survive that process untouched. But the direction of travel is about as clear as it's been.

In Short?

The Grey Belt is no longer just a talking point - it's a named list of sites, a consultation deadline, and a housing target attached to a real plan. For developers, this is the time to get ahead of the curve. If your pipeline is feeling the squeeze, or you're struggling to make the numbers stack up in central zones, start looking to the Grey Belt. It's not just an idea anymore; it's an opportunity with a postcode.

And if you want to find the best of it before everyone else does? You know where to find us!