The Core Philosophy: Openness and Permanence

The fundamental aim of Green Belt policy (outlined in Chapter 13 of the NPPF) is to prevent urban sprawl by keeping land permanently open. To the Planning Inspectorate, the two most important words are Openness and Permanence.

The 5 Purposes of the Green Belt

Before proposing a build, you must ensure your project doesn't undermine these five objectives:

To check the unrestricted sprawl of large built-up areas
To prevent neighbouring towns from merging
To assist in safeguarding the countryside from encroachment
To preserve the setting and special character of historic towns
To assist in urban regeneration by encouraging the recycling of derelict land

Know Your Land: Green Belt vs. Greenfield vs. Brownfield

These terms are often used interchangeably, but in planning law, they are worlds apart:

Green Belt

A policy designation to prevent urban sprawl. It is the hardest to build on.

Greenfield

Land that has never been built on (often meadows or farmland). It is not necessarily protected unless it is also designated as Green Belt.

Brownfield (PDL)

“Previously Developed Land.” The NPPF encourages the re-use of these sites, even within the Green Belt, provided the impact on openness is minimal.

Can I Build? The “Exceptions” List

The NPPF states that “inappropriate development” is, by definition, harmful to the Green Belt. However, certain works are not considered inappropriate. These are your “way in”:

1. Proportional Extensions

You can extend an existing building as long as it does not result in “disproportionate additions” over and above the size of the original building.

Note: Most councils define “disproportionate” as a 30% to 50% increase in volume, though this varies by local policy.

2. Replacement Buildings

A new building is acceptable if it is in the same use and not materially larger than the one it replaces.

3. Limited Infilling

In some villages, “limited infilling” (building in a small gap in an otherwise continuous built-up frontage) is permitted.

4. Agriculture and Forestry

Buildings essential for farming, forestry, or outdoor recreation/cemeteries are generally acceptable.

5. Very Special Circumstances (VSC)

If your project is considered “inappropriate,” you must prove that Very Special Circumstances exist that clearly outweigh the harm to the Green Belt. This is a high bar, often requiring proof of significant community benefit or unique design excellence (sometimes referred to as the “Paragraph 84” or “Grand Designs” exception).

Permitted Development in the Green Belt

Surprisingly, many Permitted Development (PD) rights still apply in the Green Belt. You can often build outbuildings, porches, or even some extensions under PD without a full planning application.

However, councils in Green Belt areas frequently remove these rights using Article 4 Directions. Before you start, a planning expert should check your property's specific “Permitted Development Rights” status.

The Planning Pros Strategy: The Pre-Assessment

Because Green Belt applications are subject to such intense scrutiny, we never recommend jumping straight into a full application.

Our Roadmap for Green Belt Success:

Feasibility Audit

We assess whether your project falls under an NPPF “Exception” or if we need to build a “Very Special Circumstances” case.

The Volume Calculation

We calculate the “original” volume of the dwelling (as it stood in 1948) to determine exactly how much you can extend.

Strategic Statement

We draft a robust Planning Statement that speaks the language of the NPPF, focusing on the “impact on openness.”

Key Takeaway

Obtaining planning permission in the Green Belt is an exercise in precision. It requires a planning-led approach rather than a purely architectural one. With the right strategy, your “impossible” project could become a reality.

Developing in the Green Belt: Navigating Very Special Circumstances