Works to existing higher-risk buildings – information for project teams

Planning work to an existing higher-risk building can raise many difficult questions.

• Does the work fall within the higher-risk building regime?
• Does it require building control approval from the Building Safety Regulator?
• What category of work is it?
• What information needs to be prepared?
• How do clients, designers, contractors and dutyholders ensure the right regulatory route is followed from the start?

Recent updates to the GOV.UK Code of Conduct for Registered Building Inspectors have brought these questions back into focus, particularly for work to existing higher-risk buildings where the scope may fall within defined permissible categories. For in-scope higher-risk building work, the Building Safety Regulator remains the Building Control Authority. Where plan checks or site inspections are required, appropriately registered building inspectors may be brought in by, or on behalf of, the regulatory authority to assist through the regulatory authority route, but that does not change the BSR’s role. The route may be clearer in some cases, but the scope still needs careful review…

What has changed?

The GOV.UK Code of Conduct for Registered Building Inspectors was updated in May 2026. Annex 5 of the Code sets out permissible work on existing higher-risk buildings for Class 2 Registered Building Inspectors.

It states that Class 2C and 2F Registered Building Inspectors can carry out permissible work on existing higher-risk buildings on behalf of the regulatory authority when it is the building control authority.

In practical terms, this means the BSR remains the Building Control Authority, with appropriate RBI assistance brought in on behalf of the regulatory authority where the work falls within the permitted scope. The permissible work listed includes:

• work that changes the internal layout of a residential unit within a higher-risk building, with no other Category A work permitted
• Category B work as defined in Regulation 12(6) of the Building (Higher-Risk Buildings Procedures) (England) Regulations 2023

That does not mean all work to existing higher-risk buildings is covered. It also does not remove the need for proper review, evidence or regulatory engagement. But it does create an important point for project teams to understand, particularly where planned works may sit within these narrower categories.

What is an existing higher-risk building?

In broad terms, a higher-risk building is a building that is at least 18 metres in height, or has at least seven storeys, and contains at least two residential units. During design and construction, care homes and hospitals can also fall within the higher-risk building definition where the relevant height or storey threshold is met. For existing buildings, the practical questions often arise during refurbishment, alteration, fit-out, resident improvement works, internal reconfiguration or asset management projects. Even where the work feels relatively contained, the building’s status can change the level of regulatory care needed.

Why this matters for project teams

Many project teams are now facing a common issue in that they need to carry out work to an existing high-rise residential building, but are not always clear which route applies, what category the work sits within, or how to prepare the right evidence. For example, a managing agent may be planning alterations within a residential unit.

• A contractor may be asked to deliver works in an occupied high-rise building.
• An architect may need to advise whether a proposed change affects Building Regulations compliance.
• A client may need reassurance that the correct dutyholder process is being followed.

In each case, the starting point should be a clear review of the proposed scope and the question is not just, “Can this work go ahead?”, but rather “What type of work is this, which regulatory route applies, and what evidence will be needed to support it?”

What does Category B work mean?

Category B work is defined in the Building (Higher-Risk Buildings Procedures) (England) Regulations 2023. In practical terms, this means the category of work needs to be checked against the regulations, the building type, the proposed scope and the wider compliance position. It would be risky to assume that work is Category B without a proper review. It would also be risky to assume that Class 2C or 2F capability applies to all forms of work in an existing higher-risk building. This is where early advice can help. A proper scope review can help project teams understand whether the proposed work may fall within a permissible category, what duties may apply, and what needs to happen before work progresses.

Why early advice matters

Works to existing higher-risk buildings can involve several overlapping duties.

• There may be Building Regulations requirements.
• There may be Building Safety Act duties.
• There may be dutyholder responsibilities.
• There may be Golden Thread information requirements.
• There may also be a need to coordinate technical evidence, design information and regulatory engagement.

When these points are considered too late in the process, project teams can run into avoidable problems such as missing records, unclear responsibilities, incomplete design evidence or late regulatory questions, which can all slow a project down. Early advice helps project teams make better decisions before time and cost are already committed.

How enevo can help

enevo supports clients planning and delivering works to existing higher-risk buildings. Our Building Safety team helps project teams understand the likely regulatory route, clarify duties and prepare the right information before work progresses.

This can include support with the Building Regulations compliance statement, Schedule 1 documentation where required, design evidence, Golden Thread information and wider application support. The BSR remains the Building Control Authority for in-scope HRB work.

A Building Safety-led approach, with clear role boundaries

This type of work is best approached as a Building Safety and regulatory strategy issue first.

Clients need to understand the scope, duties, evidence and route before they can make informed decisions. For in-scope HRB work, the Building Safety Regulator remains the Building Control Authority.

Where plan check or site inspection input is required, that input must sit within the correct regulatory process and registration scope. Class 2C and 2F RBIs may assist with defined permissible work on existing HRBs when acting on behalf of the regulatory authority, but this does not replace the BSR’s role.

enevo’s Building Safety team can help clients understand the wider compliance position, prepare the Building Regulations compliance statement, produce Schedule 1 documentation where called for, support Golden Thread information and coordinate the evidence needed for regulatory engagement.

That separation is important as it protects clients, supports better governance and helps avoid confusion between advisory support, Building Safety support and statutory Building Control functions.

Important limitations

The updated Code of Conduct does not mean all work to existing higher-risk buildings can be handled by Class 2C or 2F Registered Building Inspectors.

• It does not bypass the Building Safety Regulator.
• It does not remove the need for project-specific review.
• It does not remove the need for proper documentation, evidence or regulatory engagement.
• And it does not mean that works can proceed without checking the correct route first.
• Each project needs to be assessed on its own facts.

Planning works to an existing HRB?

If you are planning works to an existing higher-risk building, early advice can help reduce uncertainty. enevo can help you review the proposed scope, understand the likely regulatory route, prepare the right evidence and coordinate Building Safety and Building Control input where appropriate.Speak to enevo’s Building Safety team before work progresses.