The Building Safety Act’s golden thread is a duty about fire and structural safety, not water hygiene — so your Legionella records are not a named requirement of it. But the discipline the golden thread demands, information kept digital, accurate, current and accessible, is the exact standard good water-safety record-keeping already has to meet. An accountable person who runs both to one standard has far less to explain when someone asks.

That overlap is the point of this piece. The Act reshaped how a higher-risk residential building proves it is being managed safely, and it changed what “good records” look like in a way water-safety teams should pay attention to, even though water sits outside the Act’s formal scope.

What the golden thread actually covers

The “golden thread” came out of Dame Judith Hackitt’s review after Grenfell, and it now sits in regulations made under the Building Safety Act 2022. In plain terms it is the building’s safety information, held so the people responsible can understand and manage the building’s risks across its life, and held to defined principles: digital, accurate, kept up to date, securely stored, and accessible to those who need it.

Two words in that list do the heavy lifting for record-keeping: live and accessible. A golden thread is not a binder you produce at handover and then shelve. It is the current state of the building, updatable and retrievable on demand.

Here is the part that matters for water safety. The risks the Act is built around, the “building safety risks” an accountable person must assess and capture in a safety case report, are the spread of fire and structural failure. Legionella and wider water hygiene are not named as building safety risks under the Act. They stay governed where they always have been: the Health and Safety at Work etc. Act 1974, COSHH, and the Approved Code of Practice L8, enforced by the HSE [1][2]. So an accountable person for a higher-risk building effectively wears two hats — the Building Safety Act hat for fire and structure, and the long-standing HSE Legionella hat for the water systems.

Which buildings, and who is accountable

Scope first, because it decides whether any of this touches you. The Act’s occupation regime generally bites on higher-risk buildings — broadly, those at least 18 metres tall or with at least seven storeys, and containing at least two residential units — but the precise definition, and how the design-and-construction phase differs from occupation, is set out in the regulations and worth checking against the building you actually manage rather than assuming.

The accountable person is, in essence, the organisation or individual responsible for the safety of the building’s structure and common parts during occupation, often the freeholder or the entity that owns or repairs those parts, with a principal accountable person where more than one exists. That is not automatically the same legal person as the Legionella duty holder for the communal water system, which can be a freeholder, a residents’ management company or a managing agent depending on the lease and the management structure. Untangling that is a job in itself, set out in Who is the duty holder for Legionella in a block of flats? Freeholders, RMCs and leaseholders. Map both before you assume one person covers everything.

Why run water records to golden-thread standard anyway

If Legionella sits outside the Act, why align the two at all? Three practical reasons.

First, the people asking questions do not split the building the tidy way the legislation does. When the Building Safety Regulator engages with your safety case, when residents ask how the building is kept safe, or when an insurer reviews the asset, “how do you manage the water systems?” is a fair and likely question. Answering it from the same current, digital building information you use for everything else is a stronger position than retrieving a damp logbook from a plant room.

Second, the records overlap in substance. The water system asset register, the system schematics, the written scheme of control and the monitoring history are exactly the kind of building information the golden thread philosophy exists to keep alive. A tall residential block’s water systems carry their own difficulties — long riser runs, stored cold water that warms on upper floors, flats that sit empty for weeks — described in Legionella challenges in high-rise buildings. Those are precisely the details you want version-controlled and current, not scattered across email and paper.

Third, the direction of travel is digital, and water safety should move with it. The golden thread is explicitly a digital duty; a paper-only Legionella regime increasingly looks out of step with how the rest of a higher-risk building is now documented. Digital water-safety records already stand on their own legal footing — set out in Are digital records legally acceptable in the UK? — so there is no compliance reason to keep the water logbook on paper while the building’s safety case lives in a system.

For anyone responsible for more than one block, the same logic scales, and the trap is fragmentation across sites. Managing records across multiple sites covers keeping a portfolio’s records consistent rather than rebuilding the approach building by building.

Bringing water-safety records up to golden-thread standard

A practical checklist to test your Legionella records against the golden thread’s own principles — digital, accurate, current, accessible, secure. Work through it for one building first.

  • Digitise the live record. Move the current Legionella risk assessment, written scheme of control, asset register and schematics into the same system that holds the building’s safety information, not a separate drawer.
  • Make it the single source of truth. Retire duplicate spreadsheets and paper logs so everyone works from one version, with superseded copies archived rather than left competing.
  • Keep it current, not annual. Update the record when the water system changes — a TMV added, a flat reconfigured, a tank replaced — on the same change-control basis the Act expects for safety information, not only at the yearly review.
  • Capture monitoring as it happens. Log temperatures, flushing and remedial actions at the point of work, time-stamped, so the history is continuous and not reconstructed afterwards.
  • Define who can see and edit it. Set access for the accountable person, the Legionella duty holder, the managing agent and contractors, with a clear audit trail of who changed what.
  • Make retrieval fast. You should be able to produce the current water-safety position for a named building in minutes if the Regulator, a resident or an inspector asks.

A necessary caveat

This is general guidance, not legal advice, and the Building Safety Act and its regulations are detailed and still bedding in. Whether your building is in scope, who is the accountable person and principal accountable person, and how those duties interact, should be confirmed against the current legislation and competent professional advice for your specific building. The Legionella side stands on its own footing too: your control measures must follow from a competent, site-specific Legionella risk assessment under L8 and HSG274, not from a generic checklist [1][2].

Where to start this week

Pick the one higher-risk building you know best and lay its two records side by side: the building safety information you hold for the safety case, and the Legionella file for the water systems. Mark where the water records fail the golden thread’s own test — anything paper-only, out of date, duplicated, or slow to retrieve. That gap list is your work plan, and it is usually shorter than people fear. Close it, and when the question about the water systems arrives — and in a higher-risk building it will — the answer already sits in the same place as everything else.

Frequently asked questions

Is Legionella covered by the Building Safety Act?

Not directly. The Act’s building safety risks are the spread of fire and structural failure, so Legionella is not a named requirement of it. Water hygiene stays under the Health and Safety at Work Act, COSHH and ACoP L8, enforced by the HSE [1][2]. The connection is the golden thread’s record-keeping discipline, which is worth applying to water safety as well.

Does the golden thread legally have to include water-safety records?

As the regulations stand, the statutory golden thread is about fire and structural safety information, so water-safety records are not a legal part of it. Many accountable persons still hold them to the same digital, live and accessible standard, because it is good practice and because the questions a building faces do not stop at the Act’s boundary.

Is the accountable person the same as the Legionella duty holder?

Often related, not always identical. The accountable person is responsible for the building’s structure and common parts under the Act; the Legionella duty holder is the person in control of the premises or water system under HSE guidance [1]. In a block they may be the same freeholder or different parties, so confirm both for your building rather than assuming.

Sources

[1] HSE, “Legionnaires’ disease - what you must do”. https://www.hse.gov.uk/legionnaires/what-you-must-do/index.htm [2] HSE, “Legionnaires’ disease. The control of legionella bacteria in water systems - Approved Code of Practice and guidance (L8)”. https://www.hse.gov.uk/pubns/books/l8.htm