Before construction starts

Gateway 2 approval for higher-risk buildings, explained

Gateway 2 is the approval a higher-risk building needs before construction can start. Here is what the application must contain, and where firestopping evidence fits.

Checked against BSR guidance on 21 July 2026 · Page last reviewed . From Skyline Firestopping, a BM TRADA Q-Mark certified installer.

What it is

What is Gateway 2, and when does it apply?

Gateway 2 is the building control approval stage for a higher-risk building. It is a hard stop before construction can begin, at which the Building Safety Regulator checks that the design meets the Building Regulations. Approval has to be granted before work starts.

The gateways apply to higher-risk buildings. In law that means a building at least 18 metres tall, or with at least 7 storeys, whichever is reached first, containing at least two residential units. A building below that threshold is not higher-risk and does not pass through the gateways, though other fire-safety duties still apply to it.

There are three gateways. Gateway 1 sits at planning. Gateway 2 is the pre-construction approval covered by this page. Gateway 3 is the completion stage, before the building can be occupied. Gateway 1 is decided by the local planning authority, with the Building Safety Regulator as a statutory consultee; Gateways 2 and 3 are assessed by the Building Safety Regulator.

The application

What must a Gateway 2 application contain?

The client applies to the Building Safety Regulator with a set of documents that demonstrate how the design will comply with the Building Regulations. The core of it is a fixed list.

Checked against BSR guidance on 21 July 2026 · Page last reviewed . This list follows the current GOV.UK guidance on preparing a building control approval application. The regime is still moving, though. Treat this page as a plain-English orientation, and confirm the requirement for your own project before you submit.

Primary source: GOV.UK, “Preparing information for a building control approval application.”

A common mix-up

Gateway 2 approval, or Gateway 3 evidence?

The single most common confusion is treating installed-work evidence as a Gateway 2 input. It is not. Gateway 2 approves the design before work starts. The record of what was actually built belongs to the golden thread and Gateway 3.

Before construction

Gateway 2 — approval

Design stage. Approval required before work starts.

  • Fire strategy and the compliance approach for the design
  • How the firestopping and compartmentation strategy is intended to work
  • The tested systems the design relies on, named rather than fitted
During and after construction

Golden thread & Gateway 3

Build stage onward. Handed over at completion.

  • Installation records for the work as it actually went in
  • Photographic evidence captured before cover-up, tagged and traceable
  • The as-built information handed to the accountable person at Gateway 3
Where we fit

Where does firestopping evidence fit?

A firestopping contractor does not submit anything to the Building Safety Regulator. The client and principal contractor hold the duty and make the submission. What a specialist supplies is the evidence that goes into their documents: at Gateway 2, the tested firestopping systems named in the design and the installer’s third-party certification supporting the competence declaration; through construction, the installation record that supports the golden thread.

That is the practical value of certified installation. Skyline's firestopping is third-party certified to the BM TRADA Q-Mark, and every penetration, joint and cavity is photographed before cover-up, tagged and captured as the work goes in rather than reconstructed afterwards. When an RFI, a stop notice or a Gateway query asks the dutyholder to prove a seal, the answer is already recorded.

Common questions

Gateway 2, answered

Is there a separate evidence pack for Gateway 2?

Not as a single named document the regulator asks for. A Gateway 2 application is a defined set of documents. It includes drawings, a fire strategy, control plans and a competence declaration, among others. Firestopping evidence supports the fire-safety case within those documents; it is not a standalone pack submitted on its own.

What counts as a higher-risk building?

A building at least 18 metres tall or with at least 7 storeys, whichever comes first, containing at least two residential units. Buildings below that threshold do not pass through the gateways.

Who submits the Gateway 2 application?

The client, as the dutyholder, applies to the Building Safety Regulator (the BSR Gateway 2 submission), supported by the principal designer and principal contractor. From that point the Gateway 2 process runs on the regulator’s clock. A firestopping subcontractor does not submit to the regulator; it supplies evidence into the dutyholder's documents.

Does installed firestopping go into Gateway 2?

No. Gateway 2 approves the design before construction. Installation records and as-built photographs belong to the golden thread and are handed over at Gateway 3, the completion stage — see the regulation 38 handover duty. At Gateway 2 the firestopping question is about the strategy and the tested systems named in the design.

What happens if the application is not accepted?

The Building Safety Regulator can request further information or reject the application, and construction cannot start until approval is granted. A well-evidenced fire-safety case, with the compartmentation strategy shown to be deliverable, is part of avoiding that delay.

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 confirm the current requirement for your specific project before you rely on any list.

Get help with the evidence

Keep reading: every firestopping guide in one place

Gateway 3, the golden thread, Approved Document B, compartmentation and the rest of the regime — explained in plain English by a BM TRADA Q-Mark certified installer.

BM TRADA Q-Mark certified firestopping installer. Named on The Gherkin, Olympic Park and Grosvenor Square. Greater London and the M4 corridor.

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