Building safety duties for contractors

How the Building Safety Act affects contractors

If you work on higher-risk buildings in England - whether as a main contractor, specialist subcontractor, or SME trade contractor - the Building Safety Act 2022 creates legal duties that apply to you. These duties exist alongside your existing obligations under the Construction (Design and Management) Regulations 2015.

Be aware that the building-regulations dutyholder regime created under the Act (Building Regulations 2010 Part 2A, inserted by SI 2023/911) is not limited to higher-risk buildings: it imposes competence and cooperation duties on every client, designer and contractor for all building work in England, with written Principal Designer and Principal Contractor appointments wherever a project involves more than one contractor. What this guide covers is the additional, HRB-specific layer - the gateway regime, change control, and golden thread duties.

The Act fundamentally changes how construction work on tall residential buildings is managed. You cannot simply build to your contract specification and walk away. You have duties to cooperate with other duty holders, contribute to the golden thread of building information, report safety concerns, and comply with a formal change control process that did not exist before October 2023.

This guide explains what contractors at every level must do, with particular attention to the challenges faced by SME contractors who may be encountering these requirements for the first time.

The Principal Contractor role

Every higher-risk building project must have a Principal Contractor appointed by the client. The Principal Contractor has overarching responsibility for managing building safety during the construction phase.

Who can be Principal Contractor?

The Principal Contractor must be a contractor (not just a project manager or consultant) who has control over the construction phase. This is typically:

• The main contractor on traditional contracts
• The design-and-build contractor
• The construction management contractor with direct control

The Principal Contractor must demonstrate competence in managing Building Safety Act requirements. Previous experience of building tall residential buildings under pre-2023 rules does not automatically demonstrate competence under the new regime.

Duties of the Principal Contractor

Planning and managing construction safely

The Principal Contractor must plan, manage, and monitor the construction phase to ensure the building is built in accordance with building regulations. This includes:

• Implementing the construction control plan submitted at Gateway 2
• Ensuring all construction work complies with the approved design
• Managing the golden thread during construction - updating records as building progresses
• Coordinating with the Principal Designer on design changes
• Managing the change control process for any variations from approved design

Overseeing subcontractors and specialists

You must ensure all contractors on site:

• Are competent for the work they are performing
• Cooperate with other contractors and duty holders
• Provide information for the golden thread (test results, certifications, as-built records)
• Report safety concerns promptly
• Follow the change control process

Golden thread duties during construction

The Principal Contractor takes over golden thread responsibility from the Principal Designer during the construction phase. This means you must update digital building records to reflect what is actually built, not just what was designed.

What contractors must contribute

Every contractor on a higher-risk building project must provide information for the golden thread, including:

• As-built information: What was actually installed, including any variations from design
• Product information: Specifications, certifications, and test results for all safety-critical materials
• Test records: Results of testing for fire safety systems, structural elements, and building services
• Inspection records: Quality assurance checks and inspection reports
• Competence evidence: Qualifications and training records for safety-critical work

Provide information in the format requested by the Principal Contractor. Do not wait until the end of your work package - submit records as work progresses.

Change control after Gateway 2

Once Gateway 2 approval is granted, you cannot simply make changes as you go. The Building Safety Act introduces a formal change control regime that applies to all construction work on higher-risk buildings.

What this means for contractors

If you identify the need for a change during construction:

1. Do not proceed without authorisation. Even minor changes may need to go through the formal change control process.
2. Notify the Principal Contractor immediately. They will assess whether the change is major (requires BSR approval) or notifiable (requires BSR notification).
3. Document everything. Record why the change is needed, what alternatives were considered, and who authorised the change.
4. Wait for approval if required. Major changes need BSR approval before work can proceed. The BSR has 6 weeks (the statutory period) to determine a major change control application.

Criminal offence: Proceeding with unapproved major changes carries the same penalties as starting construction without Gateway 2 approval - unlimited fines and imprisonment.

Gateway 3 responsibilities

The Principal Contractor is one of three signatories on the Gateway 3 completion certificate application. By signing, you are confirming that the building as built complies with building regulations.

Preparing for Gateway 3

Start Gateway 3 preparation early - do not wait until construction is complete:

• Compile as-built drawings showing any changes from Gateway 2 submission
• Gather all test certificates, commissioning records, and product certifications
• Ensure the golden thread is complete and accurate
• Prepare the health and safety file for handover
• Create fire safety information for residents

The Gateway 3 application must be submitted at least 8 weeks before intended occupation. Incomplete documentation will delay the certificate and prevent occupation.

Handover to the Accountable Person

At completion, the Principal Contractor must hand over the golden thread and all building information to the Accountable Person (usually the building owner or management company). This is a critical transition point.

What you must hand over

• Complete golden thread records from the construction phase
• As-built drawings reflecting actual construction
• Health and safety file compliant with CDM requirements
• Operation and maintenance manuals for all building systems
• Product certifications and test records for safety-critical elements
• Fire safety information including evacuation procedures
• Commissioning records for all building services

Document the handover formally. Retain your own copies of all records transferred - you may need to prove what was handed over if disputes arise later.

SME contractor considerations

If you are a small or medium-sized contractor working on higher-risk building projects, the Building Safety Act requirements may feel disproportionate. However, the duties are non-negotiable and apply regardless of company size.

Practical steps for SME contractors

• Invest in training: Ensure key staff understand the Building Safety Act regime. Generic health and safety training is not sufficient.
• Establish digital record-keeping: You will need to provide information for the golden thread in digital format. Simple document management systems work - you do not need expensive BIM software.
• Check your insurance: Confirm your professional indemnity and public liability policies cover Building Safety Act requirements.
• Understand the change control process: Do not make changes to approved designs without following the formal process. Train site supervisors on when to escalate.
• Keep your own records: Even as a subcontractor, maintain your own records of the work you performed, materials you installed, and any concerns you raised.

Penalties and personal liability

How contractors can be prosecuted

• Carrying out work without Gateway 2 approval: If you start construction before the BSR has approved the Gateway 2 application, both you and the client face criminal prosecution
• Making unapproved major changes: Proceeding with changes that require BSR approval without obtaining that approval
• Providing false information: Signing false declarations or providing misleading information to the BSR
• Failing to cooperate: Not cooperating with other duty holders or not providing information for the golden thread

Directors and senior managers of contracting companies can be personally prosecuted where offences are committed with their consent, connivance, or neglect. Company size does not provide protection.