Do you need toughened or laminated glass? Where Part K applies

Where safety glass is required

Approved Document K defines the critical locations: any glazing within 800mm of floor level, and any glazing within 300mm of a door edge and up to 1500mm from the floor. In practice that catches low-cill windows, side panels next to doors, and all glazed doors themselves. Glass in these zones must be safety-rated (or meet small-pane exemptions that rarely apply to modern casements).

This is why every door we sell is glazed with safety glass only. Plain annealed double glazing isn't offered on doors at all.

What safety glass costs

Glazing is priced by the square metre of glass, so an upgrade adds more to a bigger window. Here is what each glazing option adds today on two windows, with each window's total. Each total opens the designer at that window with that glass picked.

As standard, each window is: Full Side Opener, an opening window, 600 × 900mm overall, white inside and out, double glazed (28mm), clear glass, 150mm cill, trickle vents: 2000 (300mm), white handles, standard key-locking espag lock; and Classic Combination, an opening window, 1200 × 1200mm overall, white inside and out, double glazed (28mm), clear glass, 150mm cill, trickle vents: 2000 (300mm), white handles, standard key-locking espag lock. Only the glass changes. More options are priced in our window cost guide.

Prices include VAT at 20%. Delivery is extra: priced by straight-line distance from our factory (M28 2LY) to your postcode district, from £30, to mainland Britain addresses within 300 miles, not Northern Ireland, the Scottish Highlands or islands reached by ferry. Or collect free from the factory. Delivery and collection.

Toughened vs laminated: which to pick

• Toughened: the standard safety upgrade: much stronger in service, and if it does break it granulates safely. Choose it for regulation compliance at the lowest cost.
• Laminated: breaks but holds together in the frame, like a car windscreen. Choose it where security matters (an intruder can't make a usable opening quickly), for ground-floor and door-adjacent glass on exposed elevations, or where falling glass would be dangerous.
• Both can carry obscure patterns and both are available in our 28mm double units; the 36mm triple unit is toughened as standard.

How the designer handles it

Pick your glazing per window: standard, toughened, laminated or triple. Obscure patterns reprice automatically when they're carried on a toughened unit. The regulations are the buyer's or installer's to apply on a supply-only purchase. If your cill is below 800mm or the window sits beside a door, specify a safety unit.

Frequently asked questions

How do I know if my window needs safety glass?

Measure from the finished floor to the bottom of the glass: under 800mm needs safety glass. Also within 300mm sideways of any door and below 1500mm. When in doubt, specify toughened, as the uplift is modest.

Is toughened glass double glazed?

Yes, 'toughened' describes the panes inside the sealed unit. Our toughened option is the same 28mm argon-filled construction with toughened panes.

Which is better for security, toughened or laminated?

Laminated. Toughened glass is strong but once broken it's gone; laminated stays bonded to its interlayer, so the opening remains blocked. For vulnerable ground-floor and door glazing, laminated is the security choice.

Can safety glass be obscured?

Yes, all five obscure patterns can be carried on toughened units, and the designer prices the combination automatically.

Why do your doors only come with toughened or laminated glass?

Because doors are always a critical location under Approved Document K. Plain glass would be non-compliant, so we don't offer it on any door.

Sources

The official documents and schemes this page refers to. Rules change, so check the current version, and ask your fitter or building control if you're not sure.

• Approved Document K: Protection from falling, collision and impact: safety glass and guarding