Planning Permission vs. Building Regulations: What's the Difference?

Planning permission and building regulations are two entirely separate consents — yet they're frequently confused, conflated, or misunderstood. Many homeowners are surprised to learn that a project can require one without the other, or sometimes both. Understanding the difference from the outset is one of the most valuable things we can do for our clients.

What Is Planning Permission?

Planning permission is about whether you can build — it controls the use, siting, scale, and appearance of development in relation to the surrounding area. It is administered by your local planning authority (LPA), and its purpose is to ensure that new development is appropriate for its context: that it respects neighbouring properties, preserves the character of the area, and aligns with the authority's local plan.

When you apply for planning permission, the LPA considers your proposal against a set of policies covering design quality, impact on neighbours, highway access, ecology, heritage, and much more. The decision is a matter of planning judgement, and the outcome is never entirely certain — which is why good design and a well-prepared application matter so much.

What Are Building Regulations?

Building regulations are about how you build — they set the minimum technical standards for construction to ensure that buildings are safe, structurally sound, energy-efficient, and accessible. They are administered by a Building Control Body, either your local authority or an approved private inspector.

Unlike planning permission, building regulations are not a matter of judgement about design or appearance. They are a set of technical standards — covering structure, fire safety, insulation, ventilation, drainage, electrical installations, and more — that must be demonstrably met. Compliance is verified through a series of inspections during construction and a final completion certificate at the end.

Do I Need Both?

Not always — and this is where the confusion often arises.

Planning permission without building regulations: Some minor works may require planning consent but fall below the threshold for building regulations — for example, certain boundary walls or fences, or some change-of-use applications.

Building regulations without planning permission: This is very common. Many projects — particularly those falling within Permitted Development rights — don't require planning permission but absolutely require building regulations approval. All loft conversions, for example, require building regulations regardless of whether planning is needed. So do most extensions, garage conversions, and structural alterations.

Both: Most significant residential projects — new builds, larger extensions, and anything requiring a formal planning application — will require both consents.

Neither: Very minor internal works — replacing flooring, redecorating, fitting new kitchen units without altering services — typically require neither.

Permitted Development: The Planning Exception

Permitted Development (PD) rights are a class of automatic planning consent that applies to certain types of work on residential properties in England. Under PD, a single-storey rear extension up to a specified depth, a rear dormer loft conversion, or the installation of rooflights can proceed without a planning application.

However — and this is critical — PD rights are subject to numerous conditions and exceptions. Properties in Conservation Areas, Areas of Outstanding Natural Beauty, National Parks, and World Heritage Sites have significantly restricted PD rights. Listed buildings have none. And some new developments are sold with Article 4 Directions that remove PD rights entirely.

We always carry out a PD assessment at the start of a project to establish exactly what your property can and cannot do under these rights.

The Prior Approval Process

For certain types of Permitted Development — particularly larger single-storey rear extensions under the Householder Prior Approval route — a formal application to the local authority is still required, even though it is not a full planning application. The authority notifies neighbours and has 42 days to raise any objections on specific grounds (primarily impact on amenity). If no objection is raised, the development can proceed.

This is a faster and more certain process than a full planning application, but it still requires careful preparation and a clear understanding of the permitted envelope.

Building Regulations in Practice

Once planning (or PD confirmation) is established, building regulations run alongside the design and construction process. We prepare full building regulations drawings and specifications — covering structure, thermal performance, fire strategy, drainage, and services — and submit these to the building control body before work begins.

During construction, the building inspector makes a series of site visits at key stages: foundations, structural frame, insulation, and drainage, culminating in a final inspection and completion certificate. This certificate is an important document — it's required when you come to sell the property and demonstrates that the work was carried out to the required standard.

Why It All Matters

Getting these consents right protects you in multiple ways. Unauthorised development — work carried out without the required planning permission or building regulations approval — can be difficult and expensive to remedy, can affect your ability to sell, and in some cases can lead to enforcement action by the local authority.

More positively, a well-managed consents process gives you the confidence to build. When planning permission is granted and building regulations are approved, you can proceed with certainty — knowing that what you're building is lawful, safe, and compliant.

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If you're unsure which consents your project requires, we offer an initial planning and regulatory review as part of our first consultation. Get in touch to discuss your project.