Planning Permission vs Building Regulations – what’s the difference and do you need both?

This is one of the most common mix-ups in construction, understandably people assume that once they’ve got planning permission sorted, they’re good to go but that isn’t the case. Planning permission and building regulations approval are two separate systems, run separately, applied for separately, and neither one covers the other.

So, are there two different systems, doing two different jobs?

Yes, think of it this way, planning permission is about whether you’re allowed to build something at all and considers your project’s impact on your neighbours, the street, and the local area. It looks at things like size, position, appearance and use.

Building regulations are about how it’s built. They exist purely to make sure the finished work is safe and sound, structurally stable, fire-safe, well insulated, properly ventilated, and safely wired and plumbed. One is a planning consideration and decision, whilst the other is a technical safety standard. You can have full planning permission and still be breaking the law if the building regulations side isn’t approved, and vice versa.

Are there times when you need one but not the other?

A few examples help to make this clearer:

Converting a loft, removing an internal load-bearing wall and installing a supporting steel beam, rewiring a house, replacing a boiler, or fitting a new bathroom. These don’t change how your house looks from the outside so planning permission isn’t usually needed, but every one of them affects the structure, fire safety, or electrics of your home, because of this building regulations approval is required.

Planning permission without building regulations may include certain external changes affecting appearance, for example as some alterations in a conservation area like window replacements, may need planning permission purely because of how they look, without necessarily triggering the same level of building regulations scrutiny.

The safest assumption on any project is to check both separately, don’t just assume that one covers the other.

What do building regulations actually cover?

Building regulations are broken down into ‘Parts’, each covering a different aspect of safety and performance, you may hear references to Part A (structure), Part B (fire safety), Part L (energy efficiency and insulation), Part M (accessibility), and Part P (electrical safety), among others. You don’t need to memorise these because your contractor should know exactly which ones apply to your project but it’s useful to know what regulations apply to your project.

Who gives building regulations approval?

You can apply for building regulations approval through your Local Authority Building Control team, or through a private Registered Building Control Approver. There are two routes: a ‘Building Notice’, where work can start just 48 hours after submission with fewer checks upfront, and a ‘Full Plans’ application, where your drawings are checked and approved before work begins, typically within around five weeks. Full Plans tends to give more certainty before you start, which matters most on larger or more complex projects.

What happens if you skip building regulations?

Carrying out work without the necessary building regulations approval can lead to enforcement action, and in the worst cases, being required to expose, alter or even remove non-compliant work which will be far more expensive than getting it right first time. Without a ‘Completion Certificate’ for works requiring approval you may struggle to sell your house even years later because mortgage lenders and buyer’s solicitors will routinely ask for one. Without it you may need a retrospective certificate (only available for work carried out since 2000) or indemnity insurance which can delay your sale or put off your buyer.

Our advice

For both planning and building regulations, the safest way forward is to get it right at the outset. On every project we manage, we handle both the planning and the building regulations side properly, so you end up with a home that not only looks right but is fully signed off and avoids problems when the time comes to sell. If you’re not sure what your project needs, get in touch with us, we’re happy to talk it through before you commit to anything.