The House of Lords Built Environment Committee has published its report on the Government’s Grey Belt policy. Back in October 2024, we submitted written evidence to the Committee’s inquiry and our research was referenced by the Minister of Housing and Planning, Matthew Pennycook, during his address to the Committee in December 2024. Our analysis of the impact of the Grey Belt policy, which suggested that up to 4 million homes could be delivered on these sites, was actually quoted in the House of Lords report.
So, what’s in the House of Lords report and what does it mean for the Grey Belt? Below, we’ll take a look at the key findings, provide a refresher of what the Grey Belt actually is according to the NPPF, and how LandInsight’s Grey Belt layer can help you identify sites with the highest potential for Green Belt release.
Key findings from the report
The Committee’s report highlights that the Grey Belt policy was originally intended to facilitate development on underutilised Green Belt land with limited environmental value. However, by the time the final version of the National Planning Policy Framework (NPPF) was published, the concept had been overshadowed by other planning policies, rendering it largely redundant.
Instead of establishing a distinct pathway for development, the policy now directs local authorities towards existing Green Belt review processes. The Committee raised concerns that this shift could lead to an increase in speculative development applications, rather than fostering a strategic approach to land release.
While this may come as a surprise to some, we believe this analysis is largely accurate. The concept of Grey Belt has evolved significantly from early discussions about repurposing disused petrol stations and car parks.
Understanding the role of the Grey Belt
Unlike the Green Belt, Grey Belt is not a spatial policy—it cannot simply be mapped. Instead, it is part of a broader set of changes introduced in the December 2024 NPPF, and forms part of a larger suite of planning reforms that include updates to committee delegation, council amalgamation, strategic planning, and housing targets (the Standard Method).
At its core, Grey Belt is a slogan—a useful one for sparking discussions about Green Belt release, but not a standalone solution for planning challenges.
How LandInsight's Grey Belt layer helps
Our Grey Belt layer in LandInsight may look like a spatial layer because we’ve visualised it on a map. However, Grey Belt itself is not a policy designation; rather, it is a toolkit designed to help developers and planners formulate strategies for identifying and unlocking Green Belt land for development.
The House of Lords Committee noted concerns that the Grey Belt policy could lead to speculative applications on Green Belt land, contrary to the government’s intention for planned, strategic release. Our Grey Belt layer enables users to proactively identify these speculative sites and navigate the planning process effectively. After all, 1.5 million homes won’t build themselves in this Parliament.
What's in our Grey Belt layer?
Unlike our competitors, our approach goes beyond simply filtering out flood-prone Green Belt areas and identifying previously developed land or digitising local planning authority Green Belt assessments, which were not designed for this purpose and which are likely to become obsolete following anticipated updates to Planning Practice Guidance on Green Belt review.
Instead, our approach to Grey Belt integrates multiple data points to provide a clearer picture:
- Presumption in Favour: Highlights where the presumption in favour of sustainable development is likely to apply.
- Changes to the Standard Method: Shows how housing targets have shifted, both in percentage and absolute terms so you can see where the Presumption is likely to apply in the future.
- Automatic removal of Footnote 7 constraints: Our Grey Belt later automatically filters out sites affected by these constraints.
- Proximity to existing development: Our Grey Belt layer only identifies sites within 100m of built-up areas to avoid unrealistic isolated options.
- Green Belt purpose analysis: We have protected areas around historic towns and those areas of Green belt that prevent urban coalescence, in line with the purposes of Green Belt contained in the NPPF.
These factors ensure that our Grey Belt layer identifies sites with the highest potential for Green Belt release, rather than simply generating a list of locations without strategic context.
Site ranking and planning strategies
We have ranked all the possible Grey Belt identified using the following key criteria:
- Existing land use
- Agricultural land classification
- Affordability ratios
- Connectivity
The goal is to highlight the most promising sites while flagging those that may require additional work. Each site’s ranking is displayed in LandInsight, providing a robust foundation for you to develop a planning strategy and commission the appropriate evidence to support this strategy.
Check out our free 1-pager to learn more about our Grey Belt layer in LandInsight
The House of Lords Committee report reinforced that Green Belt development should occur only in sustainable locations. The NPPF states that significant developments should be focused on areas that "are or can be made sustainable," prioritising accessibility and transport options. Our connectivity scores, based on Department for Transport data, help users build a compelling case for sustainable development.
What's next for the Grey Belt?
Does the House of Lords report signal the end of the Grey Belt as a concept? Not quite. The Committee’s conclusion that the policy has been diluted by other changes aligns with what many in the sector anticipated.
Grey Belt is not a spatial designation, and anyone claiming to have a definitive map of Grey Belt sites is missing the bigger picture.
Instead, our Grey Belt layer in LandInsight provides a toolkit to support well-informed planning strategies. We will continue monitoring relevant appeals and updating our data to ensure users have the best possible insights for navigating Green Belt policy changes.
The planning landscape is evolving, and with the right tools, developers and planners can stay ahead of the curve. Get started with the industry’s best site sourcing tool today - simply request to speak to one of our experts below to see our Grey Belt data layer in action.
