Build and manage higher-risk buildings safely

What makes a building "higher-risk"?

The Building Safety Act defines higher-risk buildings based on height, storeys, and residential use. You only need to meet ONE of the height thresholds (not both), but the building must contain at least 2 residential units to qualify.

This definition is critical for construction planning. If your project might be borderline, get confirmation from the Building Safety Regulator early - classification errors can result in criminal prosecution.

How height is measured

Height measurement follows specific rules that can affect whether your building qualifies:

• Measure from ground level to the top of the floor surface of the top storey
• Roof-top plant rooms are excluded from the measurement
• Below-ground storeys are ignored for the storey count; height is measured from ground level
• For sloping sites, measure from the lowest point of the ground level

A building measuring 17.9 metres is not higher-risk. A building measuring 18.0 metres is. Given the severe consequences of misclassification, commission a professional survey if your design is anywhere near the threshold.

The three gateway approval process

New higher-risk buildings must pass through three mandatory approval stages before anyone can occupy them. Each gateway requires formal approval from the Building Safety Regulator - you cannot proceed to the next stage without it.

Critical warning: Starting construction without Gateway 2 approval, or allowing occupation without Gateway 3 approval, is a criminal offence punishable by unlimited fines and imprisonment.

Programme implications for construction businesses

The gateway process has significant implications for project programming:

• Gateway 1 adds fire statement requirements to planning - allow 2-4 weeks additional design time
• Gateway 2 has a 12-week statutory determination period for new buildings (8 weeks for work to an existing higher-risk building). Since the 2025 fast-track reforms, the BSR's Innovation Unit determines most new applications within or close to the statutory period - check the BSR's latest published determination data and still build contingency into your programme
• Gateway 3 has an 8-week statutory period. Do not promise handover dates without this buffer
• Change control during construction requires BSR notification or approval - design changes cannot be made freely

The BSR now accepts staged Gateway 2 applications for new higher-risk buildings (for example, splitting groundworks and foundations from the superstructure), but the design for each stage must be complete and fully coordinated - piecemeal design within a stage remains a rejection risk.

Gateway 2: Pre-construction approval

Gateway 2 is the critical control point for construction businesses. You cannot break ground until you have written approval from the Building Safety Regulator.

What you must submit:

• Full design details covering structure, fire safety, and means of escape
• Fire safety provisions and fire strategy
• Access provisions for firefighters
• Drainage design
• Construction control plan showing how you'll manage changes and maintain the golden thread

Common reasons for rejection or delay:

• Incomplete fire safety information
• Insufficient detail on construction methodology
• Unclear competence evidence for duty holders
• Missing coordination between design disciplines

Gateway 3: Completion certificate

Before any resident can occupy the building, you must obtain a Higher-Risk Building Completion Certificate. This is separate from any local authority building control completion - only the BSR can issue this certificate for higher-risk buildings.

The Gateway 3 application must be signed by the client, principal designer, and principal contractor - all three must certify that the building meets requirements. This creates shared legal accountability.

Documentation required:

• Complete golden thread records from design and construction
• As-built drawings showing any changes from Gateway 2 submission
• Fire safety information including emergency procedures
• Test certificates and commissioning records
• Health and safety file for handover

Golden thread record-keeping

The "golden thread" is a digital record of all information needed to understand and manage building safety throughout the building's lifecycle. Creating and maintaining this record is a legal duty, not a best practice recommendation.

For construction businesses, the golden thread represents a fundamental change in documentation practices. You cannot rely on paper records, unstructured folders, or informal knowledge - information must be digital, accessible, and transferable.

Who maintains the golden thread?

Responsibility transfers through the building lifecycle:

• Design phase: Principal Designer creates and maintains the golden thread
• Construction phase: Principal Contractor updates as building is constructed
• Handover: Complete records transfer to the Accountable Person
• Occupation: Accountable Person maintains for building's lifetime

Practical requirements for construction:

• Establish a digital information management system before design begins
• Record design decisions AND the evidence supporting them (not just final designs)
• Capture as-built information as construction progresses - do not wait until completion
• Track all changes and record who made them and when
• Use consistent terminology throughout (do not mix different naming conventions)
• Ensure records can be transferred electronically without data loss

What the golden thread must contain during construction

During design and construction, your golden thread must include:

• Drawings, plans, and competence declarations for all duty holders
• Construction control plan
• Change control plan and log (every variation from approved design)
• Building regulations compliance statement
• Fire and emergency file
• Planning statement
• Mandatory occurrence reporting plan
• Product information for all safety-critical materials
• Test results and certifications

This is not optional documentation - missing records can prevent Gateway 3 approval and expose duty holders to prosecution.

Accountable person duties

Once a higher-risk building is occupied, an Accountable Person (AP) takes legal responsibility for ongoing safety. For construction businesses, understanding these duties is essential because:

• Developers often remain the AP until buildings are sold
• You must hand over complete information to enable the AP to fulfil their duties
• Poor handover documentation exposes both parties to enforcement action

Handover to Accountable Person

The transition from construction to occupation is a critical moment. The Principal Contractor and Principal Designer must ensure the Accountable Person receives:

• Complete golden thread records (digital, accessible, transferable)
• Health and safety file compliant with CDM requirements
• Fire safety information including evacuation procedures
• Operation and maintenance manuals for all building systems
• Product certifications and test records
• As-built drawings reflecting actual construction

The Principal Accountable Person must register the building with the Building Safety Regulator before occupation. Registration costs 251 GBP per building. Allowing residents to occupy an unregistered building is a criminal offence.

Penalties for non-compliance

The Building Safety Act introduces severe penalties that can affect construction businesses directly:

Personal liability for directors and officers

Directors, managers, and company secretaries can be prosecuted personally if corporate offences occur with their:

• Consent - you agreed to the non-compliant approach
• Connivance - you knew about it and did nothing
• Neglect - you should have known but failed to check

This means senior individuals in construction companies cannot hide behind corporate structures. If you have responsibility for building safety decisions and get them wrong, you face personal prosecution.

Limitation periods: Prosecution time limits for building regulations contraventions have been removed - the offence is now triable either way. Local authorities can serve section 36 enforcement notices up to 10 years after completion of the work. Problems discovered years later can still result in prosecution.

Action plan for construction businesses

Follow these steps to ensure compliance when developing higher-risk buildings:

Common mistakes to avoid

Underestimating gateway timescales: Under the pre-reform backlog, projects were delayed by months. Since the 2025 fast-track reforms most new Gateway 2 applications are determined within or close to the 12-week statutory period, but it is not a guarantee - build contingency into your programme.

Treating golden thread as a completion task: The golden thread must be created and maintained throughout design and construction. Trying to compile it at the end results in gaps and inconsistencies that delay Gateway 3.

Making design changes without BSR approval: Major changes during construction require BSR approval; notifiable changes require notification before work. Proceeding without approval is a criminal offence.

Incomplete competence evidence: "We've built tall buildings before" is not sufficient competence evidence. Document specific BSA experience, training, and qualifications for all duty holders.

Poor handover to Accountable Persons: Incomplete or inaccessible records create problems for building management and expose both construction business and AP to enforcement action.

Assuming previous experience is sufficient: The BSA regime is fundamentally different from previous building control. Experience under old rules does not automatically translate to competence under the new regime.