Building regulations

Do I need safety glass?

A 30-second check against Approved Document K and BS 6206, with the rule cited, not just a verdict.

Why it matters

Why bother checking?

It answers one question before you order: does the law require toughened or laminated glass where yours is going? Toughened glass cannot be cut, drilled or notched once it has been made, so this is a decision to take before we cut, not after.

It is a safety rule, not a preference
Ordinary annealed glass breaks into long shards. In a door, a low panel or a barrier, that is precisely what the regulations exist to prevent.
Your inspector will ask which rule
The verdict names the clause it applied, and the printable card records it, so the answer is on paper rather than in somebody's memory.
It also tells you when you do not need it
Not every pane sits in a critical location. Knowing which ones do not means you are not paying for toughened glass where plain float is compliant.

Go straight to the tool

Where is the glass?

Lowest edge of the glass above the floor600mm

Safety glass required

AD K4 5.1(c): wall/window glazing below 800mm. Internal or external wall glazing with any part below 800mm from the floor is a critical location.

Opens the configurator with toughened already ticked. Change the size, thickness, holes and edge finish there.

Share this verdict

Send it to your builder or your inspector. The link reopens the check with the same answers.

Approved Document K

The critical locations, in one table

Approved Document K (Building Regulations, England) names the positions where a person is likely to walk into glass or fall against it and calls them critical locations. The checker above applies exactly these rows to your answers. Heights are measured from the finished floor to the lowest part of the pane.

Approved Document K critical locations for glazing, the zone each one covers and what the document asks for
Where the glass is	Critical zone	What the document asks for	Clause
Glazing in a door	Any part of the pane within 1500mm of the finished floor	Safety glass that breaks safely under BS EN 12600 (or BS 6206), or one of the three exemptions below	AD K4, Diagram 5.1 (a)
Side panel within 300mm of either edge of a door	Any part of the pane within 1500mm of the finished floor	As for a door: safety glass, or an exemption below	AD K4, Diagram 5.1 (b)
Any other glazing in an internal or external wall or partition	Any part of the pane within 800mm of the finished floor	Safety glass, or an exemption below. Glazing wholly above 800mm is outside the critical zone	AD K4, Diagram 5.1 (c)
Small panes in a critical location	A pane no more than 250mm across its smaller dimension and no more than 0.5 square metres in area	Annealed glass is permitted if it is at least 6mm thick (traditional leaded and copper lights are treated separately; see the document)	AD K4, section 5, small panes
Thick annealed glass in a critical location	Annealed glass thick enough for the size of the pane	Permitted where the pane sits within the thickness-against-size limits the document tables; see the document for the limits that apply to your size	AD K4, section 5, robust glazing
Glazing protected by a permanent screen	A rail or barrier fixed in front of the glass that a person cannot fall through	Permitted where the screen meets the height and spacing rules the document sets; see the document	AD K4, section 5, permanent screen protection
Glass in a barrier or balustrade	Wherever the glass guards a change of level	Always safety-critical, for containment as well as impact; the barrier itself is designed to BS 6180. This is a barrier rule, not a K4 location check	AD K, sections K2 and K3
Shower screen or bath screen	At any height	Not an Approved Document K location. Shower enclosures are covered by BS EN 14428, and every compliant screen is toughened or laminated safety glass	BS EN 14428

What “breaks safely” means

The document accepts glass classified by the pendulum impact test in BS EN 12600, which grades a pane 1, 2 or 3 by the drop height it survives and adds a letter for how it breaks: B for the laminated pattern (cracks but holds together) and C for the toughened pattern (crumbles into small pieces). The older BS 6206 classes A, B and C are still quoted on legacy glass and are accepted alongside. Which class a pane must reach depends on its size; see the document.

The source

Read the document itself. This table paraphrases the K4 impact rules and names the exemptions without reproducing every limit; the document carries the diagrams and the tables that decide edge cases.

Approved Document K on gov.uk

Which safety glass

Toughened vs laminated glass

Both are safety glass when classified under BS EN 12600. The difference is how they are made and, above all, what happens when they break, and that decides which one a position calls for.

Toughened glass

How it is made: Annealed glass is cut, drilled and edge-finished, then heated close to its softening point and cooled rapidly. The surface locks in compression, which is where the strength comes from. Made to BS EN 12150.
How it breaks: Crumbles into small, blunt pieces across the whole pane. The pane is gone once it breaks, so it is not used where the glass must stay in place after failure.
Where it is required or preferred: Doors and side panels, low-level windows, shower and bath screens, splashbacks behind a hob, table tops and shelves. It is the standard answer to a FAIL on the checker above, which is why the cut-to-size button pre-selects it.
Worth knowing: Cannot be cut, drilled or notched once toughened. Every hole and cut-out is finished first.

Laminated glass

How it is made: Two or more sheets bonded with a plastic interlayer under heat and pressure. The sheets can be annealed or toughened. Made to BS EN 14449.
How it breaks: Cracks in a spider pattern but the interlayer holds the pieces together, so the pane stays in the frame and keeps the opening closed.
Where it is required or preferred: Overhead and sloped glazing, glass floors and stairs, barriers and balustrades (as laminated toughened), and anywhere security or noise matters. It is safety glass under BS EN 12600 when classified, the same as toughened.
Worth knowing: Can be cut after manufacture within limits, and is heavier and thicker than toughened for the same pane.

Not sure which your position needs? Run the check above, or book a measure visit and we will specify it on site. Pricing either is instant in the glass price calculator.

The small print, in plain English

The rules, plainly

What counts as a critical location?

Approved Document K: any glazing in a door below 1500mm from the floor, side panels within 300mm of a door edge below 1500mm, and any other wall glazing below 800mm. Balustrades and shower screens are always safety-critical.

What qualifies as safety glass?

Toughened or laminated glass classified under BS EN 12600 (formerly BS 6206). Our toughened glass is certified to BS EN 12150 with permanent kitemarking.

Is this checker legal advice?

It applies the published rules to your answers, structural factors like wind load, barrier loading and overhead glazing need a professional check. The printable card records exactly which rule was applied.

Is toughened glass the same as safety glass?

Toughened glass is one kind of safety glass. Glass counts as safety glass when it has been tested and classified under BS EN 12600 (formerly BS 6206), and both toughened glass made to BS EN 12150 and laminated glass made to BS EN 14449 are classified that way. Ordinary annealed float glass is not.

Toughened or laminated for a door?

Either satisfies Approved Document K for a door or side panel, provided the pane reaches the class the document requires for its size. Toughened is the usual choice for doors, shower screens and splashbacks because it is stronger against knocks and heat; laminated is chosen where the glass must stay in place after breaking, such as overhead glazing, some barriers and where security matters.

Can toughened glass be cut after it is made?

No. Toughening locks the surface in compression, so any cut, hole, notch or edge work must be finished before the glass goes into the furnace. Give us the finished size, the hole positions and the cut-outs, and we toughen the finished piece. Laminated glass can be cut and drilled after manufacture, within limits.

Which one for a balustrade?

Barriers are a containment rule, not just an impact rule: the glass has to hold a person back and stay in place if a panel breaks. Laminated toughened glass is the usual specification, and the barrier is designed to BS 6180 with Approved Document K sections K2 and K3. Ask us for the panel specification rather than guessing a thickness.