Metropolitan Open Land: London’s Green Space Protection

 

Metropolitan Open Land, usually shortened to MOL, is a London-specific strategic designation protecting important open land within the capital.

Under the adopted London Plan 2021, Policy G3 says MOL is afforded the same status and level of protection as Green Belt. That makes it a very strong planning constraint, but it is not literally Green Belt and its London role is different.

The position is also in transition. The draft London Plan published on 16 July 2026 proposes a new Policy PV6 with a more distinct MOL regime. That draft is not yet the adopted development plan, so this page separates the rules applying now from the changes proposed for the next London Plan.

 

What is Metropolitan Open Land?

 

MOL protects open land of strategic significance to London. It can include major parks, commons, reservoirs, sporting land, river valleys, historic landscapes and other large green spaces which perform an important metropolitan function.

The designation is set through the London planning system and borough local plans. You should therefore check the adopted policies map rather than assuming an open site in London is MOL because it looks important or publicly accessible.

MOL can also overlap with other constraints such as a Local Green Space, common land or village green, a conservation area, floodplain or ecological designation.

 

The adopted London Plan 2021 position

 

Policy G3 of the adopted London Plan says Metropolitan Open Land is afforded the same status and level of protection as Green Belt. It requires MOL to be protected from inappropriate development in accordance with the national planning policy tests applying to Green Belt.

That does not make every small structure automatically unacceptable. The planning exercise is to identify whether the proposal is appropriate within the imported Green Belt framework and, if it is inappropriate, whether the required very special circumstances exist.

For the Green Belt concepts themselves, including inappropriate development and openness, see Planning Geek’s guide to Green Belt, grey belt, greenfield and brownfield land.

 

How is new MOL designated under the adopted plan?

 

The adopted London Plan supports extensions to MOL where land meets at least one of four strategic criteria. These include contributing to London’s physical structure, containing features or landscapes of metropolitan value, forming part of a metropolitan green chain or providing open-air facilities serving London or wider areas.

The important point is scale and strategic function. MOL is not intended to be a label for every valued neighbourhood park. More local spaces may instead be protected through borough open-space policy or, where the national tests are met, through Local Green Space.

 

The July 2026 draft London Plan proposes a different PV6 regime

 

The draft London Plan changes the structure substantially. Proposed Policy PV6 says MOL should remain permanently open and distinct in character and function from the wider built-up area and should be protected from inappropriate development unless very special circumstances exist.

The draft sets its own designation functions, including:

• publicly accessible open-air leisure, recreation, sport, arts or cultural facilities of metropolitan significance
• extensive green spaces whose natural, historic or landscape qualities contribute to London’s character, biodiversity or access to nature
• strategic corridors, nodes or links within London’s green-space network

It also proposes its own categories of appropriate development, including certain minor development, replacement or alteration of buildings used for an appropriate purpose, facilities supporting outdoor sport and recreation, and infrastructure that can demonstrate a need for the particular MOL location.

 

Grey belt is a particularly important difference

 

The draft PV6 rationale expressly says that national Green Belt policies dealing with release to meet development shortfalls or with grey belt do not apply to MOL. The draft therefore moves away from the simple 2021 formulation that MOL has the same status and protection as Green Belt and instead gives MOL a London-specific strategic function.

That is one of the reasons this page needs a date attached to it. Until the new London Plan is adopted, applicants should not treat draft PV6 as though it has replaced adopted Policy G3.

 

Can MOL boundaries be changed?

 

Yes, but not casually through an ordinary planning application.

Under the adopted regime, boroughs are expected to maintain strong protection and deal with boundary changes through plan-making. The 2026 draft PV6 is more explicit: boundary alterations would require exceptional circumstances robustly demonstrated through the Local Plan process in consultation with the Mayor and adjoining boroughs.

The draft also proposes circumstances in which release might be justified, including where land no longer performs the strategic MOL function, where access and function can only realistically be improved through proportionate enabling development, or where there is an overall net gain in the quantity and quality of MOL serving a similar catchment.

Those are draft policy proposals, not a current development-management shortcut.

 

MOL compared with Green Belt and Local Green Space

 

For ordinary recreational land and playing fields, see our guide to open space, playing fields and sports land.

 

What should an applicant do?

 

1. Check the policies map and establish whether the site is MOL, adjacent to MOL or simply open land
2. Apply the adopted London Plan first because that remains the development plan unless and until replaced
3. Check the emerging plan and assess the weight that can properly be given to draft PV6 at its current stage
4. Analyse openness and strategic function rather than relying only on building footprint
5. Identify overlapping constraints including sport, common land, heritage, ecology and flood risk
6. Do not assume grey belt arguments transfer to MOL, particularly in light of the direction of draft PV6

 

Key sources

 

• London Plan 2021, Policy G3 Metropolitan Open Land
• Draft London Plan 2026, Policy PV6 Metropolitan Open Land
• National Planning Policy Framework

Conservation, Heritage & Protected Sites

 

Metropolitan Open Land Page Added: 28th August 2026