How Long Does Building Control Take

The time it takes to complete the building control process in the UK depends on the type of work, the route you choose, and how smoothly the project runs from start to finish. In most cases, building control runs alongside the construction itself — with inspections scheduled at key stages. However, how you apply and how well you prepare can affect the overall timescale.

From initial application to receiving a final completion certificate, the building control process can take anywhere from a few weeks to several months. For major developments or complex builds, it may take longer, especially if there are design changes, inspection failures, or compliance issues along the way.

Timeframes for Building Control Applications

If you're submitting a full plans application, local authorities aim to issue a decision within five to eight weeks, though it may take longer if further information is needed or plans require amendments. Once plans are approved, you can start the work knowing it meets regulation requirements — which can save time and prevent delays later on.

A building notice application is quicker to process. There’s no detailed plan check, and you can usually begin work just 48 hours after submitting the notice. This route is faster up front but can take longer overall if issues arise during inspections, since there's no advance review of compliance.

Private approved inspectors work to their own schedules and may provide plan approval more quickly than local authorities, depending on their workload and your project type. They usually aim to be more responsive, especially for repeat clients or commercial projects.

Duration of the Inspection Process

Building control inspections happen at specific stages of the build — such as foundations, damp proof courses, structural work, drainage, insulation, and final completion. The time between these inspections depends on the pace of construction.

For a small domestic extension, the full inspection process might be completed over several weeks, assuming the work is continuous and well-coordinated. For a larger build or complex renovation, the process could stretch over several months as the project unfolds in stages.

Delays often occur when the builder forgets to book an inspection, work is carried out before the inspector has checked it, or failed inspections require remedial work before the project can continue. These gaps in communication or planning can push back the final sign-off date.

Receiving the Completion Certificate

The final stage of the building control process is the completion inspection. Once the work is finished, you must notify building control so they can carry out a final check. If everything is in order, the completion certificate is usually issued within a few days.

However, if there are outstanding issues — such as missing paperwork, minor defects, or unresolved safety concerns — the certificate may be delayed until these are corrected. If work has been completed without interim inspections, the inspector may require parts of the building to be exposed to confirm compliance, which can extend the timeline significantly.

Factors That Can Delay the Process

The most common delays in building control arise from poor communication, missing information, and skipped inspections. If you fail to notify building control at the right stages, or if drawings and structural details are incomplete, the inspector may be unable to proceed.

Changes to the design after approval can also cause delays, as these may need to be reassessed for compliance. Using unregistered contractors or doing DIY work without clear documentation can raise red flags and lead to more inspections or longer assessment times.

Seasonal demand is another factor. During peak building periods — particularly spring and summer — local authorities and inspectors may have longer lead times for site visits. Booking inspections early and sticking to an agreed schedule can help reduce delays.

Different Stages, Different Timeframes

The building control process isn’t a single action — it’s a phased series of steps that move with your project. How long it takes depends on which phase you’re in and how efficiently you or your contractor manage it.

The initial application phase can take anywhere from a day to several weeks. A building notice allows work to start after a short wait — usually 48 hours. A full plans application takes longer because it involves reviewing technical drawings, which can take five to eight weeks, depending on complexity and whether revisions are needed.

Once the application is accepted, the inspection phase begins. This part is less about fixed timescales and more about coordination. Building control moves at the pace of your build — if the project stalls, so does the inspection schedule.

Booking Inspections and Waiting Times

Most local authority building control teams offer next-day or two-day inspection slots, especially for common site checks like foundation trenches or pre-plaster inspections. However, during busy periods — such as summer or pre-Christmas — availability may stretch to three or four working days.

Private approved inspectors often offer faster, more flexible appointments, particularly for developers or repeat clients. However, their availability still depends on demand and the size of their team.

Booking inspections as early as possible, even tentatively, can reduce wait times. Last-minute bookings or repeated cancellations can throw the schedule off track and add unnecessary delays.

What Can Speed Things Up

The biggest time-saver is good preparation. Submitting detailed, regulation-compliant plans, using qualified professionals, and following best practices during the build significantly reduces the risk of delays.

Consistent communication with your inspector is equally important. If you keep them informed, book inspections promptly, and respond to queries without delay, the process stays on track.

Using contractors who understand building control requirements — and who work regularly with inspectors — helps avoid repeat visits or remedial work, both of which slow progress.

When Timeframes Are Legally Important

Some projects are time-sensitive by law. For example, if you're converting a property under permitted development rights, you often need to complete the work within a set period after notification. In these cases, a slow building control process could impact your planning compliance, not just your schedule.

New builds also need a completion certificate before they can be legally occupied or sold. If a buyer is ready to move in but the certificate hasn’t been issued, the entire sale can be delayed. Developers and sellers should factor this into their handover timelines.

Completion Certificate Delays

Final sign-off is often assumed to be immediate once the work is finished — but in reality, it depends on two things: the final inspection and having all supporting documents in place.

Missing paperwork, such as structural engineer sign-off, energy performance calculations, or installer certification (for gas, electrics, etc.), is one of the most common reasons for delayed certificates. Making sure all documentation is submitted in advance of the final inspection can cut the waiting time down to just a few days.

Final Word

The building control process doesn’t follow a single fixed timeline — it moves with your project. A well-managed job with clear communication and prompt inspections can receive sign-off within weeks. Poor coordination or skipped steps can drag the process out for months. The key is to involve building control early, keep them informed throughout the work, and respond quickly to any issues they raise. Done properly, building control runs smoothly in parallel with your build — and wraps up with the certificate that confirms everything has been done right.