Safety Glazing: Approved Document K Guide for UK Glaziers

England: Approved Document K

In England, glazing that people might walk into is covered by requirement K4 of the Building Regulations and by Approved Document K (2013 edition, in force since 6 April 2013), which absorbed the old Approved Document N. Section 5 defines the critical locations:

glazing in a door, between floor level and 1500 mm;
glazing within 300 mm of the edge of a door, between floor level and 1500 mm;
any other glazing between floor level and 800 mm — low-level glazing in walls and partitions.

What the glass in a critical location must do

In a critical location, glazing should do one of three things:

Break safely — classified to BS EN 12600 (the pendulum impact test) as Class 3 or better, or Class C of BS 6206. For door and side-panel panes wider than 900 mm the bar is higher: Class 2 (or Class B).
Be robust, or in small panes — for example annealed glass at least 6 mm thick in small panes, or 4 mm in traditional leaded lights, within the limits Approved Document K sets out.
Be permanently protected — behind a screen or barrier that stops people falling against it.

In practice that usually means toughened or laminated glass. Approved Document K also covers manifestation (making large panes visible) and safe opening and cleaning — read it in full for those.

BS 6262-4

BS 6262-4 is the British Standard code of practice for glazing safety related to human impact; the current edition is BS 6262-4:2018. It is the industry's detailed reference — the Scottish and Irish guidance cite it directly — even though England's Approved Document K works from the BS EN 12600 classes above.

Wales, Scotland and Northern Ireland

Wales didn't take England's 2013 merger: glazing safety is still in a Wales-only Approved Document N, alongside Wales's own Approved Document K.
Scotland — Building Standards Technical Handbook, standard 4.8: glazing within 800 mm of the floor, any glazing in a door leaf, and glazing within 300 mm of a door leaf and within 1.5 m of the floor should meet BS 6262-4 or be guarded.
Northern Ireland — Technical Booklet V (Glazing), covering regulations 96 to 99.

A routine that avoids the expensive mistake

At the survey, record where each opening is — in or beside a door, low level, a bathroom — with a photo.
When you quote, put the glass and its safety class on the line.
When you order, make sure the purchase order carries the same description.
On the day, check the safety-glass mark before it goes in.

Where Coglass fits

Coglass gives guidance — it is not a sign-off, and the final choice stays with you:

A heads-up on the line. On the work bench, when a pane is larger than a quick-reference UK guide for its glass type and thickness, Coglass shows a note; and for larger annealed panes it reminds you that doors, side panels and low-level glazing normally need safety glass. Guidance only, never a hard stop.
A safety-glazing library. Coglass comes with notes on doors, low-level glazing, side panels, shower and bath screens, balustrades and overhead glazing that you can edit, switch off or add to.
Online sales checked. When the Coglass webshop launches (coming soon) and you sell glass through it, customers are asked where the glass is going: non-safety glass is blocked for doors, glass within 300 mm of a door, low-level glazing and bathrooms, and balustrades and overhead glass come to you as an enquiry.
Surveys on the phone. Each opening is measured, drawn and photographed, with notes, GPS and the access level — and it works with no signal, syncing when you are back in coverage.
The glass written down once. The product and make-up you pick on the line goes on the quote, the supplier's purchase order and the workshop's cutting sheet, so everyone works from the same specification.

Want to see it on your own jobs? Book a demo or see pricing in GBP.

Sources

This page explains the rules in general terms. Standards and tax rules change, and how they apply depends on the job — check the source, your building control body or your accountant before relying on it.

Safety glazing in critical locations: a guide for UK glaziers