Do I Need Building Control for Permitted Development

Permitted development allows homeowners and developers to carry out certain types of building work without applying for planning permission. It’s a useful route for extensions, loft conversions, outbuildings, and internal alterations — as long as the work stays within specific size and design limits. But there’s often confusion about what this means for building control.

The short answer is yes — even if your project qualifies as permitted development, you still need to comply with building regulations. Planning and building control are two separate systems. One governs how a building looks and where it’s placed; the other governs how it’s built and whether it meets legal safety and performance standards.

The Role of Building Control Under Permitted Development

Building control approval is required whenever construction work affects a building’s structure, safety, or essential systems. Permitted development may give you the right to build without applying for planning permission, but it doesn’t exempt you from the need to follow the building regulations.

For example, if you're building a rear extension under permitted development rules, the structure still needs to be inspected for compliance with regulations covering foundations, drainage, insulation, structural support, and fire safety. Likewise, converting a loft or garage without planning permission still requires full building control approval, because the new space must meet standards for thermal performance, ventilation, stairs, fire escape, and headroom.

If you’re installing electrical wiring, altering drainage, or fitting heating systems, these works also fall under building control — whether or not the overall project needs planning permission.

When Building Control is Not Required

Building control isn’t always needed for very small, non-structural works. If your permitted development project involves only minor cosmetic improvements or simple repairs — such as painting, replacing fixtures, or re-roofing with like-for-like materials — you may not need approval.

That said, the moment your work affects structure, insulation, fire resistance, or any regulated system (like heating or electrics), building control steps in. It’s always best to confirm with your local authority or an approved inspector before assuming your work is exempt.

Common Permitted Development Projects That Still Require Approval

Loft conversions are one of the most common types of permitted development — but they nearly always require building control. This is because structural changes are involved, new floors and walls are added, and fire safety routes must be reassessed.

Single-storey extensions, rear extensions, and side return infills built under permitted development must also be approved through building control. Even garden rooms or outbuildings — if they’re intended for sleeping, working, or long-term use — often require building control oversight, especially if they include plumbing or fixed electrical systems.

Internal knock-throughs, even under permitted development, usually require building control too, particularly if load-bearing walls or fire doors are affected.

Importance of Completion Certification

Building control approval isn’t just a box to tick during construction — it’s your legal record that the work was carried out safely and to UK standards. At the end of the process, a completion certificate will be issued if everything complies.

Without this certificate, you may struggle to sell or insure your home. Solicitors, mortgage providers, and insurers all expect to see evidence that building regulations have been followed — regardless of whether the project needed planning permission.

Permitted Development Doesn’t Mean Fewer Building Standards

Permitted development only waives the need for planning permission, not the standards that apply to how something is built. This is a key distinction. Under permitted development, the scope of what you can build is relaxed, but the quality and safety of the construction still has to meet national Building Regulations.

So, whether you’re adding a rear extension, converting a garage, or upgrading a roof under permitted development rules, the insulation, fire protection, drainage, and structural integrity of that work must still be inspected and approved. The law makes no exception on safety grounds just because the work is permitted in planning terms.

Notification Requirements Still Apply

Just because you’re not applying for planning permission doesn’t mean you can skip notifying your local authority. Under building control rules, you must either submit a building notice or a full plans application before starting any regulated work. If you’re using a private approved inspector, they’ll issue an initial notice to inform the council they’re taking over building control duties.

Failure to notify building control before starting work can lead to enforcement action, delays, or extra costs — even if your plans were fully permitted from a planning perspective.

Inspections Still Happen Under Permitted Development

Even under permitted development, you’ll still be required to arrange site inspections at key stages of construction. This includes trench inspections for new foundations, damp-proof course checks, structural frame inspections, insulation installation, and a final inspection at completion.

Skipping these inspections or covering up work before it's checked can result in failed approval and possible orders to open up finished work for reinspection — all of which delay your project and increase costs.

You May Still Need Planning Approval for Some Details

Even if the overall structure falls under permitted development, certain elements might still require separate planning or listed building consent. This often applies to:

• Drainage: Redirecting rainwater or foul drainage to new systems may require planning or water company approval.

• Windows and Rooflights: If your property is in a conservation area or a listed building, some changes to glazing still require planning sign-off.

• Materials: Using certain external finishes may trigger planning checks depending on location and visual impact.

In these cases, building control approval alone isn’t enough — both systems must be satisfied.

Building Control and Future Property Sales

Buyers and solicitors will often request a building control completion certificate as part of the property sale process. If you’ve built under permitted development but didn’t obtain the relevant building control approval and certificate, it could cause delays, legal complications, or even result in a reduced sale price.

This applies to both major work — like loft conversions and kitchen extensions — and to internal structural changes. Even well-finished projects can cause red flags for buyers if there’s no documented proof that the work met safety standards.

Final Advice: Check Before You Build

Even if your architect or builder tells you a project qualifies for permitted development, that doesn’t mean building control can be ignored. Always contact your local building control body or a private approved inspector at the planning stage. Confirm what type of application is required and what inspections will be needed.

Taking this step early avoids delays, protects your investment, and ensures the final result is both legal and insurable.

Final Word

Permitted development gives you planning freedom, but it doesn’t remove the need for building control. Structural work, electrical systems, insulation upgrades, loft conversions, and extensions still require approval to meet the legal standards for health, safety, and performance. If in doubt, ask building control before starting work. It’s the easiest way to make sure your project stays compliant, protected, and fully documented.