Building safety beyond the higher-risk threshold

The 18-metre line has come to dominate how people talk about building safety, and it is easy to see why. It is the point at which the heaviest part of the regime switches on, with registration, a safety case and a named dutyholder accountable to a regulator. But the attention it attracts has a side effect. It can leave the owners and managers of everything below the line with the impression that building safety is somebody else's problem, and that a building which falls short of the threshold falls outside the duties. That impression is wrong, and it is a dangerous place to manage from.

The threshold changes which regime applies. It does not change whether you have a responsibility to understand and manage the fire risk in your building. A six-storey block, a converted office, a low-rise estate of flats: none of these is a higher-risk building, and all of them carry duties that existed before the higher-risk regime and continue regardless of it.

What the threshold actually defines

It helps to be precise about what the line is. In England a higher-risk building, for the purposes of the occupation regime, is one at least 18m tall or with at least 7 storeys, whichever comes first, containing at least 2 residential units; hotels, care homes and secure or military accommodation are excluded from that occupation-phase definition. Where a building meets it, the Building Safety Act 2022 brings in the Accountable Person, the requirement to register the building, and the duty to hold a safety case and produce a safety case report for the Building Safety Regulator.

Everything in that paragraph is about a specific regime for a specific class of building. None of it says that a building below the threshold is unregulated. It says that a building below the threshold is regulated differently, and the difference is the point most often missed.

The duties that do not depend on height

The foundational fire safety duty in England is not in the Building Safety Act 2022 at all. It is in the Regulatory Reform (Fire Safety) Order 2005, and it applies to the responsible person of the great majority of non-domestic premises and the common parts of blocks of flats, regardless of height. That duty includes making a suitable and sufficient fire risk assessment and keeping it up to date. The Fire Safety Act 2021 then clarified that the assessment must cover the structure, external walls including cladding and balconies, and flat entrance doors, and that clarification is not limited to tall buildings.

So a manager of a low-rise residential block sits squarely inside the fire safety regime even though they sit outside the higher-risk one. The list of obligations that do not wait for 18 metres is long:

• A current fire risk assessment under the Regulatory Reform (Fire Safety) Order 2005, with the Fire Safety Act 2021 scope.
• Working fire safety measures, escape routes and the management arrangements behind them.
• Periodic electrical inspection of rented homes, at least every 5 years under the gov.uk landlord rules.
• Lift thorough examinations under LOLER, every 6 months for passenger lifts and 12 for load-only.
• Whatever duties flow from the building's specific use, tenure and contents.

A building can be entirely below the higher-risk threshold and still carry every one of these.

Where the high-rise residential duties begin

There is also a middle band worth naming, because it confuses people. The Fire Safety (England) Regulations 2022, in force 23 January 2023, place specific duties on responsible persons of high-rise residential buildings, defined as those 18m or more or with 7 or more storeys with at least 2 domestic premises, including sharing plans and external wall information with the fire and rescue service, keeping plans in a secure information box, and monthly checks of firefighters' lifts and key equipment. These duties track the same height as the higher-risk definition but sit in a different instrument, so a building can attract them without the full Building Safety Act 2022 occupation regime applying in the way people assume. The lesson is not to reason from a single number to a single conclusion. Each duty has its own trigger, and they do not all switch on at the same line. Our note on higher-risk buildings: who counts and what changes at 18 metres untangles the thresholds in more detail.

Managing the building you actually have

The practical consequence is that good building safety management cannot be organised around the question "are we a higher-risk building". It has to be organised around the question "what duties apply to this specific building, and can we evidence that we are meeting them". For a building below the threshold, that means a current and properly scoped fire risk assessment, the maintenance and inspection cadence its services require, and a record that holds all of it together. The fact that no safety case is required does not mean no evidence is required.

In fact, the discipline that the higher-risk regime formalises, knowing your building, holding its information accurately, keeping it current, is good practice for any building, not just the ones the law compels. The golden thread is a statutory concept for higher-risk buildings, but its underlying idea, an accurate and current record of the building held through its life, is exactly what a manager of a sub-threshold block benefits from too. Holding your buildings and their risk assessments to the same standard of evidence, whatever side of the line they sit, is the posture that ages well as duties expand.

The threshold is a floor, not a ceiling

It is worth saying plainly. The higher-risk threshold marks where the most demanding regime begins, not where responsibility begins. Responsibility begins with occupation. A manager who treats the 18-metre line as the start of their duties has misread it; it is the start of one particular set of duties, layered on top of obligations that were already there. The buildings below the line are the majority of the stock, and managing them well is most of the work. None of this is legal advice, and the duties applying to any specific building should be confirmed against the live position by a competent person, but the principle holds: the threshold tells you which rules, never whether any rules apply.