Building Safety Act gateways 1, 2 & 3. The evidence pack that gets signed off.
A higher-risk building cannot be occupied until it clears its final gateway. That decision turns on the record of the work as built. The Building Safety Act sets three gateways: planning, building control approval before construction, and completion before anyone moves in. This page walks through all three, and the firestopping evidence Gateway 3 expects.
What are the Building Safety Act gateways?
The gateways are three decision points a higher-risk building must pass through: Gateway 1 at planning, Gateway 2 before construction can start, and Gateway 3 at completion, before anyone can move in. At Gateway 1 the Building Safety Regulator (BSR) advises the planning authority. Gateways 2 and 3 are the regulator's own decisions, and work cannot start, nor occupation begin, until each is cleared.
The gateways apply to higher-risk buildings: at least 18 metres tall or with at least 7 storeys, whichever is reached first, containing at least two residential units. During design and construction the same height test also captures hospitals and care homes. The regime the gateways sit inside — the Act, the dutyholders and the golden thread — is covered in our explainer on fire safety legislation and the golden thread. This page is about the gateways themselves: what each one decides, and the evidence that has to exist by the time the last one is reached.
Three gates across the programme, one thread underneath
Read a build programme left to right and the gateways are the three points where it stops until the regulator says otherwise. The golden thread runs underneath all three: started at design, added to as the work goes in, and handed over at Gateway 3. From there it is kept for the building's occupied life.
Schematic. Each project's gateway submissions, decision points and evidence requirements are set by the Building Safety Regulator's current guidance, not by this drawing.
What does each gateway decide?
Gateway 1
Fire safety considered at the planning application.
- A fire statement sets out how the development approaches fire safety
- Site layout questions — access for fire appliances, water supply — are settled early
- Decisions here fix the frame the later gateways will test against
Held by the client and Principal Designer
Gateway 2
Building control approval. Work cannot start until it is granted.
- The client applies to the Building Safety Regulator with drawings, a compliance statement, a fire and emergency file and control plans
- For firestopping, the question is the design: tested systems named, details that resolve
- The application stage is covered in detail in our Gateway 2 approval explainer
Held by the client, Principal Designer and Principal Contractor
Gateway 3
The completion check, before the building can be occupied.
- The regulator checks the building was built as the approved design said it would be
- The as-built evidence gathered through construction is what answers that question
- The golden thread is handed to the Accountable Person and kept current in occupation
Passes to the Accountable Person
What does Gateway 3 ask of firestopping evidence?
The Building Safety Act Gateway 3 stage asks one question of the firestopping in a building: can you show the work was installed as the approved design said it would be? By completion, every penetration, joint and cavity is hidden behind a finished wall or above a ceiling. The only way to answer is the record made while the work was still visible. That is why the evidence is captured as the work goes in, never reconstructed afterwards. A folder of certificates says the work happened; an as-built record shows each seal, where it is, what tested system closed it, and who installed it.
- Photographed before cover-up Every penetration, joint and cavity is photographed before, during and after installation. The wall never closes over an unphotographed seal.
- Tagged, batch-traced and geo-located Each seal carries its own tag — company, installer, date — traceable to its location and the tested system it was installed as.
- Captured into the golden thread as installed The record enters the golden thread as the work goes in. At handover it passes to the Accountable Person, complete, and is kept current for the occupied life.
Where a building reaches completion without that record — or an existing building has no record at all — a firestopping survey establishes the current position, floor by floor, so the evidence has a defensible starting point.
What does a Gateway 3 evidence record look like?
The record that clears completion is the same record that survives an RFI, a stop notice and 15 years of liability. Three parts do the work.
Independent proof, not our word for it. Skyline installs BM TRADA Q-Mark certified tested systems and evidences every installation this way. Skyline’s work is behind the walls of The Gherkin, Olympic Park and Grosvenor Square.
Who answers at each gateway?
A firestopping contractor does not submit anything to the Building Safety Regulator. The client and principal dutyholders make each BSR submission; what a specialist supplies is the evidence inside their documents. At Gateway 2 that is design-stage confirmation that the compartmentation strategy — the compartmentation and cavity-barrier duties set out in Approved Document B — is deliverable with tested systems. Through construction it is the installation record. At Gateway 3 it is the as-built evidence the regulator reads before the building can be occupied.
| Stage | Who answers for it | The firestopping evidence at that stage |
|---|---|---|
| Gateway 1 · Planning | The client and Principal Designer | The fire strategy takes shape; no installed work exists yet. |
| Gateway 2 · Before build | The client, Principal Designer and Principal Contractor | Tested systems named in the design; the compartmentation strategy shown to be deliverable. |
| Construction | The Principal Contractor | Every penetration, joint and cavity photographed, tagged and captured into the golden thread as installed. |
| Gateway 3 · Completion | Passes to the Accountable Person | The as-built record handed over complete, then kept current for the building's occupied life. |
Dutyholder roles under the Building Safety Act 2022. The dutyholder regime itself — who the roles are and how the duty transfers — is covered in the legislation explainer.
Gateway questions, answered
What are the Building Safety Act gateways?
Three decision points a higher-risk building must pass through under the Building Safety Act 2022. Gateway 1 sits at planning, where the regulator advises the planning authority. Gateway 2 is the building control approval required before construction can start, and Gateway 3 is the completion stage before the building can be occupied. The Building Safety Regulator decides Gateways 2 and 3 itself.
Which buildings do the gateways apply to?
Higher-risk buildings: at least 18 metres tall or with at least 7 storeys, whichever is reached first, containing at least two residential units. During design and construction the same height test also captures hospitals and care homes. Below that threshold a building does not pass through the gateways, though other fire-safety duties still apply.
What is Gateway 2?
The building control approval stage: a hard stop before construction can begin, at which the Building Safety Regulator checks that the design meets the Building Regulations. The client applies with a defined set of documents: drawings, a compliance statement, a fire and emergency file and control plans among them. The full application list is on our Gateway 2 approval page.
What is Gateway 3?
The completion stage, before a higher-risk building can be occupied. The regulator checks the building was built as the approved design said it would be, using the as-built information gathered through construction. The golden thread record is handed to the Accountable Person, who keeps it current in occupation.
Does installed firestopping evidence go into Gateway 2?
Not usually. Gateway 2 approves the design before construction, so the firestopping question at that stage is about the strategy and the tested systems named in the design. Installation records and photographs of the work as it actually went in belong to the golden thread and are handed over at Gateway 3.
What happens after Gateway 3, once the building is occupied?
The duty does not stop at completion. In occupation the Accountable Person keeps the golden thread current and maintains the building safety case, an ongoing assessment of how fire and structural risks are managed. From it they produce a building safety case report, the live evidence the Building Safety Regulator can call in when it issues the building assessment certificate. Safety-critical failures are notified through mandatory occurrence reporting. The as-built firestopping record handed over at Gateway 3 is the foundation those occupation-phase duties are built on.
Is this guidance current?
It was checked against Building Safety Regulator and GOV.UK guidance on 21 July 2026. The regime is still settling, so treat this page as a plain-English orientation and confirm the current requirement for your own project before you submit anything.
Page updated .