How Planning Inspectors Actually Make Decisions

If you've ever been involved in a planning appeal, you'll know that sinking feeling when you realise your fate rests in the hands of someone you've never met.

A Planning Inspector will read your case, visit your site, and make a decision that could mean the difference between your project going ahead or hitting a brick wall.

But who are these inspectors, really? How do they think? What rules govern their decisions? And most importantly, are they actually independent, or just rubber-stamping what the council already decided?

I've worked with planning appeals for years, and I can tell you that the system is far more structured and principled than most people realise. Let me pull back the curtain and show you how inspectors actually make decisions.

The Inspector's True Role: More Independent Than You Think

Here's something that surprises most people: when an inspector decides your appeal, they're not acting on behalf of the Secretary of State in the way you might imagine. Yes, they're appointed by the Secretary of State, but for most appeals (what we call "transferred casework"), they exercise completely independent judgment.

Think of it this way: the inspector isn't phoning up the government department asking what to decide. They're making their own call, based on the evidence before them and national planning policy. They must apply the same policies the Secretary of State would apply, but the decision is genuinely theirs.

This matters because it means your appeal gets a fresh, independent look.

The inspector hasn't been involved in any previous discussions about your site. They haven't had coffee with the council planning officer. They're coming to your case with genuinely fresh eyes.

There is one important exception though.

Some high-profile cases are "called-in" or "recovered" by the Secretary of State. In these situations, the inspector writes a report with recommendations, but the final decision sits with the Secretary of State. These are relatively rare and usually involve nationally significant issues, so for most appeals, you're dealing with genuine inspector independence.

The Three Principles That Guide Every Decision

Back in 1957, a committee chaired by Sir Oliver Franks examined how administrative tribunals and inquiries should operate. What they came up with—the Franks Principles—still guides every planning inspector today. These aren't just nice ideas; they're fundamental to how the system works.

Openness: No Secret Handshakes

Inspectors cannot receive secret briefings. Everything they know about your case, the other parties know too. All the policy documents, all the evidence, all the technical reports—it's all out in the open.

This means no one can whisper in the inspector's ear behind closed doors. If new evidence emerges, it must be shared with everyone. If there's a relevant policy document, all parties get to see it and comment on it.

Fairness: Everyone Gets Their Say

Every party with an interest in the decision must get adequate notice of proceedings and a proper opportunity to state their case. This includes the right to respond to what others have said.

In practice, this means the inspector has to ensure the process gives you a fair crack of the whip.

If you're appealing against a refusal, you get to explain why the council got it wrong. If you're the council, you get to defend your decision. If you're a neighbour with concerns, you get to have your say too.

The inspector must also give you enough time to prepare your case properly and must not make decisions based on information you haven't had a chance to see or respond to.

Impartiality: No Axes to Grind

Here's the big one: inspectors must be genuinely impartial. They can't have a predetermined view. They can't favor one party over another. And crucially, they must be seen to be impartial.

This is why inspectors are so careful about their conduct. They won't accept a cup of tea from you at a site visit (yes, really). They won't have informal chats with one party outside the formal proceedings. They maintain professional distance precisely because their impartiality is essential to the legitimacy of their decision.

If you think about it, these three principles create a system where everyone knows the rules, everyone gets a fair hearing, and the decision-maker has no hidden agenda. It's not perfect, but it's designed to be as fair as humanly possible.

Natural Justice and the "Wednesbury" Test

Beyond the Franks Principles, inspectors must also apply what lawyers call "natural justice." This essentially means a duty to act fairly and without bias. It's a backstop that ensures procedural fairness even when specific rules don't cover a particular situation.

But there's another fascinating legal concept that shapes inspector decisions: Wednesbury reasonableness. Despite the peculiar name (it comes from a 1948 court case involving a cinema in Wednesbury), this is actually quite straightforward.

What Makes a Decision "Unreasonable"?

An inspector's decision is considered legally flawed if they:

• Take into account factors they shouldn't have considered

• Fail to take into account factors they should have considered

• Reach a decision so unreasonable that no reasonable authority would ever consider making it

That last point might sound circular, but the courts have explained it quite clearly. A decision is irrational if it "doesn't add up"—if there's an error of reasoning that robs the decision of logic.

In practical terms, this means an inspector can't just ignore important evidence. They can't give weight to irrelevant matters. And they can't reach a conclusion that simply doesn't follow from the evidence before them.

I've seen appeals lost because an inspector failed to properly consider highways safety evidence. I've also seen appeals won because an inspector correctly identified that a council had placed far too much weight on a single objection letter while ignoring substantial technical evidence.

The Wednesbury test doesn't mean the inspector has to agree with you—it means their reasoning must be logical and based on relevant considerations.

Avoiding Bias: Why Inspectors Are So Careful

You might have noticed that inspectors can seem quite formal, even stiff, at hearings and inquiries. There's a good reason for this: they're being extremely careful not to give any impression of bias.

The legal test for apparent bias asks whether "a fair-minded observer would conclude that there was a real possibility that the tribunal was biased." Notice that this isn't about actual bias—it's about the appearance of bias.

This is why inspectors:

• Avoid chatty conversations with individual parties

• Won't discuss the case informally during breaks

• Ensure that if one party points something out on a site visit, all parties are present to hear it

• Maintain the same level of formality with everyone

Now, inspectors are human beings, not robots.

The courts have recognised that different inspectors have different styles. Some are warmer, some are more formal. That's acceptable. What's not acceptable is treating parties differently or giving any impression that minds are already made up.

I once watched an inspector politely but firmly cut off an appellant who tried to engage in small talk before a hearing started. It might have seemed rude, but the inspector was simply protecting the integrity of the process. That same firmness applies to everyone equally.

The Three Types of Appeal Procedure

Not all appeals are handled the same way. Understanding which procedure your appeal follows helps you understand what the inspector is doing and why.

Written Representations are the most common route. Everyone submits their evidence in writing, the inspector visits the site, and then makes a decision based on the written material. It's efficient and works well for straightforward cases.

Hearings are more structured discussions. The inspector chairs the session, working through the issues with the parties present. There's no formal cross-examination—it's more of a round-table discussion. Hearings work well when there are technical issues that benefit from discussion but don't need the formality of an inquiry.

Inquiries are the full courtroom-style procedure. There's formal evidence, cross-examination, opening and closing statements—the works. These are reserved for complex or controversial cases where evidence needs to be properly tested.

Interestingly, inspectors now have the power to change the procedure if they think the original choice isn't appropriate. If a case turns out to be more complex than initially thought, a written representations appeal might become a hearing. The parties get a say in this, but the inspector makes the final call based on what's needed to properly understand the evidence.

What Inspectors Can't Do

Understanding the limits on inspectors is just as important as understanding their powers. These constraints aren't weaknesses—they're features of the system designed to ensure fairness.

They Can't Comment on Government Policy

Inspectors must apply national planning policy as set by the government. They can interpret how policy applies to a specific case, but they can't criticise the policy itself or suggest it should be different.

So if you're arguing that a particular policy is unfair or poorly conceived, that argument won't get you anywhere with an inspector. They have to work within the policy framework that exists.

They Can't Have Private Conversations

Every conversation about the substance of your case must happen in the open, where all parties can hear it. If someone tries to collar an inspector during a site visit to make a point privately, the inspector will stop them and make sure everyone is present before proceeding.

This can feel frustrating if you're trying to be helpful, but it's essential to fairness.

They Can't Accept Hospitality

Inspectors won't accept gifts, hospitality, or benefits that might compromise their judgment. This extends even to a cup of tea during a site visit. It might seem overly cautious, but it avoids any suggestion of improper influence.

They Can't Rescue Bad Applications

This is crucial to understand: an inspector can only work with what's before them. If your application was poorly presented or lacked key information, the inspector can't fill in the gaps for you. They assess the proposal as it stands.

How Inspectors Actually Assess Your Appeal

So what does an inspector actually do when they receive your case file?

First, they review all the material to understand what's at issue. They're looking at the application or proposal, the council's reasons for refusal, your grounds of appeal, any third-party representations, and all the relevant planning policies.

They're asking themselves questions like: What's the main controversy here? What evidence do I need to evaluate? Are there any procedural issues I need to address? Is this case properly allocated to me, or does it need specialist expertise?

Before or during the site visit, they're absorbing the specifics: What does the site actually look like? How does it relate to its surroundings? Can I see what the parties are talking about in their submissions?

Throughout this process, they're testing the arguments against the evidence and the evidence against the policies. They're weighing up competing considerations. They're checking that their reasoning is logical and addresses the key issues.

The Human Rights Dimension

One final layer that's worth understanding: every inspector decision must comply with the Human Rights Act. This means respecting people's rights to a fair hearing, to their property, to their private and family life.

In practice, this is largely covered by following the Franks Principles and natural justice. But it's an important backdrop—the planning system as a whole, including the right to challenge decisions in court, must comply with human rights requirements.

Inspectors also have responsibilities under the Equality Act to consider equality impacts. Again, if they're following proper principles of fairness and taking all relevant matters into account, they should meet these requirements.

What This Means for Your Appeal

Understanding how inspectors make decisions should actually give you confidence in the system.

Yes, there will be winners and losers. Yes, you might disagree with the outcome. But the process is designed to be fair, open, and impartial.

When you're preparing your appeal, remember:

• The inspector genuinely wants to understand your case

• They're required to consider all relevant evidence you put forward

• They must explain their reasoning in a way that makes logical sense

• They're independent and not predisposed to favor either side

Your job is to present your case clearly, back it up with solid evidence, and make sure you address the relevant planning policies. The inspector's job is to weigh everything up fairly and reach a reasoned decision.

The system isn't perfect, but it's far more structured and principled than most people realise.

Behind every inspector's decision is a framework of legal principles, procedural safeguards, and professional obligations designed to deliver fair outcomes.

Understanding this won't guarantee you'll win your appeal, but it should help you approach the process with more confidence and less anxiety. And that alone can make a real difference to how you prepare and present your case.

Author

Andrew Ransome is the planning director at ADP and is a chartered member of the RTPI, with over 22 years of town planning experience.

Andrew has extensive experience offering strategic planning solutions to challenging projects in both rural and urban settings. Follow him on Linkedin.

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