Do All Changes of Use Need Planning Permission?

If you are buying a property, changing how a building is used, or starting a new business from an existing premises, you have probably heard this advice:

“You’ll need planning permission because it’s a change of use.”

It sounds straightforward — but in planning terms, it can be wrong.

In reality, not all changes of use need planning permission, and some changes of use are not development at all. Understanding why can save you time, cost, and unnecessary planning applications.

This article explains the basics.

A Common Mistake: Assuming “Change of Use” Always Means Permission

It’s easy to understand why people assume that a change of use always needs planning permission. After all, most planning applications are about changing how land or buildings are used. But the starting point of planning law is very clear: only “development” needs planning permission.

That means the first question is not “Has the use changed?” but:

“Is this change of use ‘development’?”

If the answer is no, then planning permission isn’t needed — even if the use feels very different.

So What Counts as “Development”?

Under the Town and Country Planning Act 1990 (TCPA 1990), planning permission is required for most development — but there are some very clear exceptions. One of these exceptions arises from section 55(2)(f) of the TCPA 1990, which says that certain kinds of changes of use “shall not be taken to involve development of land.”

That sounds technical, but If a building or piece of land is used for one purpose within a specific category (called a “use class”), and it changes to another use within the same category, that change is not development and doesn’t need planning permission.

This might seem like a minor point, but it is hugely important — and surprisingly poorly understood.

Understanding the Use Classes System

To make sense of this, we need to understand the Use Classes Order (UCO). This is simply a way of grouping similar uses into categories so the law can treat them consistently.

Think of use classes as buckets of similar activities. If two uses are in the same bucket, swapping between them is often a non-event in planning terms.

For example, many everyday commercial uses are now grouped in Class E:

• Shops

• Offices

• Restaurants and cafés

• Gyms and fitness studios

• Medical and health services

• Financial and professional services

Because all of these fall within Class E, changing a shop into a café or a gym, or an office into a consultancy, doesn’t count as development as long as the use stays within that class and there are no restrictive planning conditions. That’s true even if the character of the activity feels quite different to your neighbour.

This principle comes straight from the law — section 55(2)(f) — and is reflected in the Use Class Order. It was also confirmed many years ago in the case of Carpet Decor (Guildford) Ltd v Secretary of State and Guildford DC [1981] JPL 806, where the Court held that a change between two uses in the same use class was not development.

“Sui Generis” Uses and Mixed Uses

Some uses don’t fall into any specific use class. These are called sui generis, meaning “in a class of their own.” Common examples include:

• Public houses (pubs)

• Cinemas

• Hostels

• Car showrooms

• Scrapyards

• Vehicle hire depots

Because they are not in a use class, changes involving these uses often need closer scrutiny and often require planning permission. But again: different class does not alway need for planning permission. The real question is still whether the change is a material change of use.

There’s an important point here about mixed uses.

If a site genuinely has more than one use at the same time (for example, a café with offices and storage on the same site), that is usually treated as a single, mixed use, and may require a specific planning permission.

There’s also the idea of incidental and ancillary uses. If some secondary use is simply part and parcel of the main use — like an office inside a care home used strictly for administration — that secondary use doesn’t create a new planning use. As long as it’s “ordinarily incidental,” it won’t affect the planning position.

What About Residential Uses?

Most houses are in Class C3 (dwellinghouses). Changing between different kinds of household living (for example, house to flat) often involves planning permission, especially if it creates a new “planning unit.” That’s because subdividing a dwelling into multiple separate units alters the planning unit itself and is development, even if the uses all look “residential.”

Unauthorised Uses and the “Clock” on Enforcement

Here’s something that surprises a lot of people: if a use started without planning permission, and then later the use changes within the same use class, that does not reset the enforcement timeline.

Under section 171B of the TCPA 1990, certain uses can become lawful after 10 years if no enforcement action is taken.

In R (on the application of Harbige) v Secretary of State for Communities and Local Government [2012] EWHC 1128 (Admin), the High Court confirmed that when an unauthorised use changes to another use within the same use class during that 10-year period, the enforcement “clock” continues running from the date the original unauthorised use began.

Continuity counts even if the original use was unlawful so long as no development occurred in changing within the class.

This area matters mostly for enforcement and lawful development certificate cases, but it’s another example of how planning law focuses on real impact.

Permitted Development Rights: A Separate Concept

It’s worth distinguishing between changes that are not development (because of the use class rules) and changes that are development but are allowed by “permitted development rights.”

Those rights are different — they are a set of specific allowances in the General Permitted Development Order (GPDO) that let you do certain developments without a full planning application.

Some changes of use (for example, office to residential in certain circumstances) have permitted development rights attached.

But those are separate from the use class exemptions — and often come with conditions or limits.

Also, as confirmed in Kwik Save Discount Group Ltd v Secretary of State and Others [1981] JPL 198 (CoA), permitted development rights only apply where the original permission has been genuinely implemented — a token implementation won’t get you the benefit.

So don’t mix up “not development because of use classes” with “development that is allowed because of PD rights.” They are different mechanisms.

Can Councils Restrict Changes Within a Use Class?

Yes — and planning law recognises this.

If the council is concerned about the impacts a future change of use might have, it can impose conditions on a planning permission that limit changes of use — even within the same use class — or it can remove permitted development rights.

However, such conditions must be justified and meet the tests for planning conditions (they must be necessary, relevant, precise, enforceable, and so on).

This was highlighted in recent cases such as Lazari v Secretary of State for Levelling Up, Housing and Communities & London Borough of Camden [2023] EWHC 2026 (Admin), which explored how conditions restricting use should be interpreted in light of the use class regime.

The practical takeaway: just because something is lawful under the use class rules doesn’t always mean a change will happen without restriction. Protective conditions can shape how a property can be used in future.

So What Should You Do in Practice?

Here are the key things to keep in mind:

• Don’t assume a change of use automatically needs planning permission. If it stays within the same use class, sometimes it’s not development.

• Different use classes don’t automatically mean development. You still need to ask whether the change is a material change of use.

• Check for permitted development rights separately. They’re a different mechanism.

• If a use has evolved without permission, get early advice. Enforcement timelines can be tricky.

• If in doubt, apply for a lawful development certificate. It gives clarity and peace of mind.

• Always consider real-world impacts. Planning law cares about effects on neighbours, traffic, noise, and similar issues — not just the technical label.

Final Thoughts

The world of planning law often feels complicated — and in detail, it can be.

Understanding why the law distinguishes between different kinds of change of use, and why some changes don’t need permission at all, will put you in a much stronger position whether you’re leasing a shop, converting a building, or just curious about how planning works.

About Me

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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