Steel Side-Hung Windows – Inward Opening


Also referred to as a side-hinged or turn window, a steel side-hung inward opening window is attached to the one vertical side of the frame by hinges and open inwards towards the room. When it is fully opened, it provides maximum ventilation and easy access.

Steel framed side-hung windows offer slimmer sightlines and increased durability.

Design and Aesthetic


  • Thermally broken profiles as standard 
  • A basic depth for thermally broken steel windows is between 50-70mm.
  • Slim sightlines

Materials and Surface Finishes


  • Strip galvanised steel (Allowing full range of standard powder coated RAL colour options)
  • Corten
  • Stainless steel
  • Marine grade powder coated for for use in marine and coastal environments

Size Limitations


  • Standard sash sizes for steel side-hung window are up to 1 metre in width and 2.3 metres in height.
  • A steel side-hung window sash may weigh up to 150kg. 

Opening options


  • Side-hung inward opeing, single sash
  • Side-hung inward opening, double sash (no mullion in the centre when both window sashed are open)

Safety & Security Options


  • Steel side-hung windows come usually with standard multi-point locking systems.
  • Burglar resistance classes of RC2, RC3 or PAS24 are available as security options,
  • Restrictor can be used to limit the amount of opening of the side-hung windows for safety.

Glass Options


  • Double glass option for a standard size side-hung window: 4-20-4, toughened glass, 20mm argon filled cavity, Ug-value of 1.0 W/m2K, low-e coating, warm edge spacers, light transmission over 70%) 
  • Triple glass option to achieve better thermal performance.
  • One pane of glass unit can be built with laminated glass for additional security or safety for preventing fall through, overhead glazing and full height glazing.

Thermal Performance


  • Thermal performance of a steel side-hung inward opening window depends on its frame and glass combinations.
  • A typical inward opening steel side-hung window can achieve a U-value less than 1.4 W/m2K with a double glass (Ug=1.0 W/m2K).
  • For better U-values, triple glass must be choosen.

Weather-tightness Performance


A typical inward opening steel side-hung window should meet the following minimum weather-tightness performance values:

  • Air tightness: Class 4 (600 Pa)
  • Water tightness Class 9A (900 Pa)
  • Wind load resistance: Class C4 (1600 Pa)

Regulations and Standards


An inward opening steel side-hung window to be installed at your property is subject to building regulations and certain standards:

  • Windows to be installed on the ground floor of new buildings must have PAS24 securilty level. (Part Q, Read More >> )
  • Windows to be installed at your property must comply with Approved Document L in terms of thermal performance ( Read More >> )
  • Windows must comply trickle vent requirements specified in Approved Document F (Read More >>)

Buyer’s Guide to Steel Windows


Steel tilt-turn double opening window on a brick wall

Common applications of inward opening steel side-hung windows

  • For maximum ventilation or fully access,
  • Ideal choice for the areas where easy cleaning is required from inside.
  • Suitable for above ground floors and multi-storey buildings,
  • Suitable for areas where emergency exit or escape windows are needed.