The Gateway 3 application, step by step

When can you apply for Gateway 3?

You apply for a completion certificate once the notifiable building work is complete. That sounds obvious, but it carries a trap: the application is only valid, and the 8-week statutory clock only starts, when the work is genuinely finished and the evidence is genuinely there. An application submitted against a building that is not really complete, or against records that do not match what was installed, is not a fast application. It is a rejected one.

Build UK recommends giving the BSR at least 8 weeks notice of your intent to apply, which is sound. The regulator has to plan a final inspection and assessor time around your completion, and warning it early is how you avoid the certificate slipping because nobody at the BSR knew you were coming.

What does the Gateway 3 application contain?

Gateway 3 is an as-built evidence test. Where Gateway 2 asked what you intended to build, Gateway 3 asks what you actually built and demands the proof. The core of the application is:

• As-built plans and documents reflecting what was actually constructed, not the design intent
• Compliance declarations signed by the principal designer and the principal contractor
• Evidence that safety systems have been installed and commissioned correctly
• Complete change control records covering every deviation from the approved design
• The golden thread information, to be handed over to the accountable person

The signed declarations are personal and specific. The principal designer and principal contractor are declaring compliance against the real building, so the document set has to agree with the fabric. Where the record says one thing and the installation says another, the declaration cannot honestly be signed, and the application cannot be determined.

What does Gateway 3 cost, and how long does it take?

Item	Amount or period
Application fee	189 pounds
Assessor time	151 pounds per hour, per assessor
Statutory determination	8 weeks from a valid application
Final inspection	Mandatory; the BSR must arrange it before determining

Treat the 8 weeks as the determination period, not the total. The realistic timeline is the notice period plus the assembly of valid, matching evidence, plus the determination, plus the final inspection inside it. That is why the practical completion to occupation gap on a higher-risk building is measured in months and has to be a named risk in the contract.

How does the final inspection work?

The BSR must arrange a final inspection before it can determine the application. This is not a formality bolted on at the end; it is the regulator satisfying itself that the building in front of it matches the evidence in the application. Anything the inspection turns up that contradicts the record, an as-built discrepancy, a commissioning gap, an uncontrolled change, becomes a reason the determination stalls. The inspection rewards projects whose paperwork and building already agree.

What is partial completion, and when can you use it?

A partial completion certificate lets part of a building be occupied while the rest is finished, but only where a partial completion strategy was agreed with the BSR at Gateway 2. It is a planned route, decided at the design stage, not a rescue for a slipping programme. It is also not generally suitable for handing over individual flats or floors, so it does not solve the problem of wanting to release residential units piecemeal. If phased occupation matters to your commercial model, it has to be designed into the Gateway 2 submission, not improvised at the end.

Why is registration separate, and why does it matter?

The completion certificate is necessary but not sufficient. Before anyone occupies a higher-risk building, the principal accountable person must also register it with the BSR. These are two distinct steps, and occupation before both is a criminal offence. The practical lesson is to treat registration as a parallel workstream to the completion application, not an afterthought, so that the day the certificate arrives is not the day you discover the building still cannot lawfully be occupied. Line up the accountable-person duties, the safety case work and the registration alongside the Gateway 3 application, and you close out the regime cleanly instead of tripping over the last lock on the door.