Critical locations for safety glazing

Below 800 mm from floor level in walls and partitions; below 1500 mm in doors and in side panels within 300 mm of a door edge

Internal and external glazing in a dwelling

Zones in which glazing must be safety glass, break safely, or be small or robust enough to be exempt.

Basis in regulation

Part K
Approved Document K
Read the source

How to check it on site

Check the kitemark or safety mark on each pane in the critical zones at handover, including glazed side panels and low-level windows.

Common failure

A glazed side panel next to a front door left in annealed glass because only the door leaf was specified as toughened.

Last updated 23 August 2026. This is our editorial summary of publicly available regulation, not building control approval or a warranty determination.

Related dimensions at this stage

Minimum

Hearth Provision and Floor Finishes

225 mm

A hearth may not be necessary if an appliance's flame or incandescent material is positioned at least 225mm above the floor

Minimum

Soundproofing Measures for Soil Pipes

25 mm

Sound insulation for soil pipes involves either encasing them in boxing made from a material with a minimum mass of 15kg/m², or wrapping them with at least 25mm of unfaced mineral wool, typically 10kg/m³ density

Minimum

Electrical Accessory Clearance from Water Diagrams

300 mm

Diagrams illustrating the required 300mm minimum horizontal clearance for electrical accessories from water sources, such as sinks and wash basins, are commonly used in guidance documents

exact

Conditions for Pipe Freezing Calculations

6 °C

Calculations for pipe insulation to prevent freezing are based on specific assumed conditions, typically including an external air temperature of -6°C and an internal water temperature of +7°C

Minimum

Water seal depth at appliance traps

75 mm for baths, basins, sinks and showers on a branch; 50 mm for a WC trap

Appliance trap on a branch discharge pipe

Minimum

Stair Handrail Height and Clearance

600 mm

A handrail is mandatory for flights of stairs where the rise exceeds 600mm