# NI Building Regulations, Technical Booklet V: Glazing Safety
Technical Booklet V is about glazing, safety in relation to impact, opening and cleaning. It's there to stop people getting cut by glass if they walk into it, make big clear panes obvious, and make sure windows can be opened and cleaned safely.
1. Impact with glazing, "if you hit it, it shouldn't shred you"
In critical locations, the glazing must either:
- Break safely (safety glass to the right standard and marking).
- Be robust enough to resist impact without breaking.
- Be in small panes that won't cause serious injury if they break.
- Be permanently protected by a screen or barrier.
Critical locations include:
- Glass in and next to doors (down to a certain height).
- Low-level glazing in walls and partitions where children and adults move about.
Manufacturers link this to BS EN 12600 and BS 6262 for impact-tested safety glass.
On site: if the drawing or spec says "safety glass / toughened / laminated / safety marked" in doors, side panels or low-level glazing, that's not optional. You cannot quietly drop to cheaper float glass.
2. Transparent glazing, "make the big glass obvious"
Where you've got glass doors or large areas of clear glazing and people could collide with them, you must have permanent manifestation.
- Doors made of glass or big uninterrupted clear panes in risk areas must have manifestation in set zones.
- Manifestation can be logos or signs at least 150mm high, or solid/broken lines at least 50mm high.
- It must have good visual contrast with the background so people can actually see it.
Think: visible bands or logos on shopfront glass, office partitions, and big sliding doors.
On site: don't "value engineer" away the frosting, bands or logos because they "spoil the look." That's literally the bit that keeps you compliant with V.
3. Safe opening and closing, "no one should get clobbered or fall out"
For any window, rooflight or ventilator that opens, Booklet V expects it can be opened, closed and adjusted safely:
- Controls positioned where they can be reached safely · not needing daft stretching over voids or sinks.
- Limiting openings or guarding where someone could fall through while using the window.
- Openers that don't swing out into walkways where people pass.
On site: if the detail shows restrictors, stops or guards, fit them. Don't move handles or change opening types without checking what that does to reach, falls risk or head-banging risk.
4. Safe access for cleaning, "you can clean it without doing something stupid"
Booklet V expects a safe way to clean any glazing that's designed to be cleaned:
- Clean from inside using suitable-reach windows and openings.
- Clean from outside with safe access.
- Use specialist access kit · but the building must include space and fixing points (for cradles, MEWPs, towers, etc.).
There are diagrams showing maximum reaches for cleaning from inside, and notes on providing space for tower scaffolds or anchor points. It points to BS 8213-1 for more detail.
On site: if the design intent is "cleanable from inside," don't change that window for one you can't reach properly. If the plan relies on towers or cradles, don't block access routes or miss out the fixing points.
5. Simple rules for real jobs
- Anywhere near doors, stairs, corridors or low-level · assume it might be a critical location and needs safety glass or proper protection.
- Big clear panes need visible bands/logos · if you're not sure, leave them in and ask. Don't take them off.
- Don't swap window types, restrictors or handle positions without checking falls and reach.
- Make sure there is a believable way to clean what you're building that doesn't involve circus-act ladders.
Sources
- Building Regulations (Northern Ireland) Order 1979 · primary legislation.
- Technical Booklet V (NI) · Glazing (Regulations 96–99, Part V).
- BS EN 12600 · glass impact testing standard.
- BS 6262 · glazing for buildings.
- BS 8213-1 · windows and door sets, including cleaning access.
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