Balcony and window safety in a home with small children: railings, nets, locks

This article describes how to reduce the risk of falls for small children in a high-rise apartment, drawing on mainstream press; it does not replace advice from an engineer or a safety professional. Updated 24 October 2026.

Balconies, loggias and windows are the most dangerous points of a high-rise apartment when small children live there. The risk is high because a single moment without an adult is enough. This article summarises the figures quoted in the press, the layers of protection to put in place and how to check them when you take over an apartment.

1. What the current standard says

Section 2.2.12 of QCVN 04:2021/BXD (Circular 03/2021/TT-BXD, effective 5 July 2021; the text was opened on LuatVietnam) provides that fences, railings, balconies and loggias must, in addition to meeting the safety requirements of QCXDVN 05:2008/BXD, have a clear height from the floor to the underside of the window opening / window sill in an apartment building of no less than 1.4 m.

Points to understand correctly:

• The 1.4 m figure is measured to the underside of the window opening or window sill; it is not by default the height of the railing bars. Railing height and gaps are set in QCXDVN 05:2008/BXD, which this section refers to; the text of QCXDVN 05:2008/BXD has not been opened for cross-checking.
• Hà Nội Mới newspaper (1 March 2021) also mentions a gap that does not let a 100 mm diameter ball pass through, and avoiding horizontal bars that children can use as footholds. The article quotes the QCVN 04:2019/BXD version, which has been superseded, so treat it as reference information only, not a current regulation.
• Some commercial websites give 1.1 m or 1.2 m without citing the correct provision; do not use them.
• The architect quoted in the article notes that the standard has no illustrations, so the actual safe height may be lower if the railing sits on a beam or a plinth, or has horizontal bars a child can climb.

2. Windows: do not rely on the lock alone

Hà Nội Mới newspaper (1 March 2021) reports that most children under 5 can squeeze through a gap of about 30 cm. Recommendations include:

• Install nets or protective frames on windows and balconies.
• Lock the balcony door and keep the key or lock out of children's reach.
• Do not place furniture (chairs, tables, beds, low cabinets) next to windows and balconies, because children can climb on it.
• Never leave a child alone on the balcony, even for a few minutes.

3. Layers of protection to have

Layer	What to do	Note
1	Keep the balcony door locked, with the lock out of children's reach	Choose the right child lock for the door type
2	Railing that is high enough, with nothing to climb	Check horizontal bars, plinths, planters
3	Net or protective frame	Choose sturdy material and install it properly
4	Windows with a limited opening	Fit a stopper
5	Furniture layout	Move items away from windows and balconies
6	Supervision	An adult always within sight

4. Balcony nets, "tiger cages" and building rules

Installing a net or an iron frame outside the balcony may affect the building's facade appearance and its fire prevention and fighting rules (escape routes, ventilation openings). Ask the building management which type of net, colour and position is allowed before installing. Do not build a "tiger cage" that fully covers an escape door.

No official provision on balcony nets has been cross-checked; this needs to be confirmed with the building management and the fire prevention and fighting unit.

5. When viewing and taking over an apartment

Quick checklist:

1. Measure the railing height and the distance from the floor to the window sill with a tape measure; ask the developer or building management for the design specifications and the current regulations.
2. Check the gaps between vertical bars: the bars should be close enough that a child cannot squeeze through (100 mm according to the newspaper article, to be cross-checked against QCXDVN 05:2008/BXD).
3. Look for horizontal bars, wide plinths or planters that a child could climb.
4. Test the balcony door lock: is there an inside lock, and is it out of children's reach?
5. Check the glass and windows: sturdiness of the frame, hinges, how far they open.
6. Ask how installing a net / frame is allowed.
7. Record unsafe points in the handover minutes (taking over a home).

6. Household habits

• Teach children not to climb or push each other at windows and balconies.
• Have an adult close the balcony door right after use.
• Do not place chairs or heavy vases next to the railing.
• Hang laundry only where children do not need to go near.
• If you rent, check the points above before moving in (apartment rental contract).

7. If you are a landlord

Units for families with small children are often asked about the balcony. Check the railing and door locks, and state in the contract who is responsible for installing a net (preparing a unit for quick sale or rental).

Note: this article does not replace the standard or engineering advice. Child safety does not rely on a single measure; always combine railings, locks, nets and supervision.

• LuatVietnam — National technical regulation QCVN 04:2021/BXD on Apartment Buildings (section 2.2.12; Circular 03/2021/TT-BXD, effective 5 July 2021, replacing QCVN 04:2019/BXD), accessed 24 October 2026. It sets no railing gap requirement; it refers to QCXDVN 05:2008/BXD.
• Hà Nội Mới newspaper — Dạ Khánh, How should apartment railings be built to be safe?, 1 March 2021 (quotes QCVN 04:2019/BXD and QCXDVN 05:2008/BXD; recommendations for small children; for reference only).