The Approved Document B rewrite, and the edition your building was built to

Approved Document B is the statutory guidance on fire safety for building work in England. It is the document that says how wide a stair should be, how long a wall has to resist fire, and what a compartment is. It has been amended in pieces for years, and the Building Safety Regulator has now consulted on the largest coherent set of changes since Grenfell.

The consultation ran for fourteen weeks, from 25 March to 1 July 2026. The government response is expected this summer. Every proposal in it carries the same target implementation date, 2 September 2029, which lines up with the amendment booklet already published for that date and lets a complete new version of the guidance take effect in one go rather than as another layer of patches.

Three years is a long lead time, and it is easy to file this under things to worry about later. That would be a mistake, though not for the reason you would expect.

What is actually being proposed

The proposals are broad, and most of them are about how new buildings get designed rather than how existing ones get run.

Combustible structural elements above 11 metres. The consultation introduces an 11 metre threshold above which a building using combustible structural elements, timber included, cannot rely on Approved Document B alone and needs a fire-engineered solution. Below that height the guidance still works as a route to compliance. This is the proposal that has drawn most of the industry comment, because it draws a clear line under where the standard guidance stops being a safe default.

Evacuation lifts above 18 metres. The guidance would recommend evacuation lifts in residential buildings over 18 metres. The threshold matches the higher-risk building definition, so it does not introduce a new height to remember. Where a firefighting lift is already provided, it can serve both functions.

External walls and balconies. The guidance on fire spread over external walls is revised and its scope extended to the wall system as a whole rather than to individual components. There is a proposed narrow exemption to the combustible materials ban for laminated glass balustrades within a defined thickness range.

Car parks. Fire resistance requirements for open-sided multistorey car parks increase from 15 minutes to 30 minutes between 5 and 18 metres, and from 15 minutes to 60 minutes above 18 metres.

Specialised housing. The term "sheltered housing" is retired in favour of "specialised housing", with a distinction drawn between housing that provides regulated personal care and housing that does not. Where care is provided, the proposals increase alarm coverage to category LD1 and grade D1.

Roofs. Updated guidance on fire stopping where compartment walls meet the roof, and, for the first time in a meaningful way, provisions for photovoltaic panel installations.

The regulator puts the total cost at £199 million over ten years, with a net annual cost to business of around £29 million.

Why a manager of existing buildings should read it anyway

Approved Document B governs building work. It does not retrospectively apply to a building that is already standing and already occupied. Nobody is going to require you to add an evacuation lift to a 2014 block in 2029.

What it does do is describe, in unusual detail, what the current view of good practice is. And several of the proposals are about things that arrive in an existing building through the side door, which is refurbishment.

Solar panels go onto roofs of buildings that were designed before anyone thought about them. Balconies get replaced. Car parks get re-clad or re-decked. A block gets a new entrance or a reconfigured bin store. Each of those is building work, and building work is assessed against the guidance current at the time it happens. A refurbishment specified in 2030 against a 2019 mental model of Approved Document B is a slow and expensive conversation with a building control body.

There is also the fire risk assessment. An FRA is not a building regulations compliance check, and a competent assessor will not mark a building down for meeting the standard it was legally built to. But the assessor's judgement of whether the fire strategy still works is informed by current thinking, and current thinking is about to be written down in one place with a date on it.

The record that makes this manageable

Here is the practical part, and it is smaller than the consultation makes it sound.

For each building you look after, you should be able to answer one question quickly: which edition of the guidance was this designed and built against, and what has changed since.

That sounds obvious. In practice it is one of the least reliable pieces of information in most portfolios, because it lives in a handover pack that arrived on a memory stick, or in a building control completion certificate in a drawer, or in nobody's hands at all after two changes of managing agent.

A useful version of the record is short. The completion or final certificate and the date of the work. The edition of Approved Document B in force at that point. The fire strategy document, if one exists, and the assumptions it makes, most importantly whether the building is stay put or simultaneous evacuation. The design assumptions that matter later: compartmentation lines, external wall build-up, whether there is a firefighting lift and what it was specified to do. Then, dated against the same building, every material alteration since, with its own approval and its own date.

That last part is where the value sits. A building is rarely built once. It is built once and then modified fifteen times, and the fifteen modifications are what the fire strategy has to survive. When a proposal like the external wall revision lands, the question you need to answer is not "what does the new guidance say", which anyone can read. It is "what is on my external walls, when did it go on, and under what approval", which only your own records can tell you.

Where this sits in SAMRISK

The point of holding a building's design history in the same place as its running record is that a change in guidance becomes a query rather than a project.

The safety case is where the fire strategy and the design assumptions live, alongside the evidence that supports them. Materials records what a building is actually made of, including what went on during a refurbishment rather than only what the original specification said. Building plans hold the compartmentation and the escape routes as drawings that get updated rather than reprinted. Documents carries the completion certificates, the approvals and the handover pack, attached to the building rather than to a folder structure.

Fire safety holds the assessment and its actions, maintenance holds the recurring checks on the systems the strategy depends on, and tasks is where a finding becomes work with an owner and a date. When a refurbishment is proposed, the contractors and permits record ties the work back to the approval it was done under, so the next person can see it.

None of that changes what the guidance says. It changes how long it takes to work out whether the change matters to you.

What to do before 2029

Very little, urgently. Rather more, calmly.

Read the consultation if you commission building work, because your designers will be working to this from September 2029 and the transitional arrangements will matter to anything specified close to the line. If you only manage existing stock, the reasonable response is to spend the intervening period making sure each building's design record is actually findable, and that every alteration since handover has been captured against it.

Guidance changes on a published date. Buildings change quietly, on no date at all, unless somebody writes it down.