Domestic External Applications

Our members can manufacture steel windows and doors using W20 hot rolled steel profiles using SMW, W20 and W40 hot rolled steel profiles. Doors are manufactured using W20 and W40 hot rolled steel profiles. These are the slimmest steel profiles that are able to create steel doors, door screens and windows that comply with current building regulations.

The majority of domestic external steel doors and door screens that are seen on social media will be manufactured from the W20 system as it has the slimmest profiles and therefore provides stunning aesthetics between the outdoor space and the home.

Doors can be manufactured as double or single hinged swing doors up to a maximum of 1800 mm wide and 2400 mm high (both maximums cannot be specified at the same time). Runs of fixed or opening glazing to the sides or above the doors can be fabricated to ensure that an entire space can be filled.

Some customers will want a screen design with more than one set of double doors so as to provide a link between the garden and home when they are in the open position.

Shaped frames are also possible and so gables, raked heads and arches are not a problem for our members.

Hot rolled steel profiles from the SMW, W20 and W40 ranges have been tested and assessed to BS 476 Pt 22 enabling us to offer fire resistant glazing which will maintain integrity in a typical fire in the case of fixed lights and screens for 30 minutes and in the case of fixed lights for 60 minutes.


Standard Metal Window (SMW) ‘F’ series window range has been manufactured since the 1890s, and is a stylish solution for a number of aesthetically-sensitive historical projects.

Available as single or double glazed, SMW windows are primarily used today for bespoke replacement work in conservation areas and listed buildings, where a suitable geometric match is required.

These windows can be glazed using an external glazing bead, putty (not advised with double glazing) or silicone fronted for an authentic appearance. These frames are galvanised and can be powder coated for low maintenance. They use single point locking, an external hinge and a simple weather-stripping detail. Each frame is made from recycled steel to add a further eco-friendly credential.

The frames glazed using single glazing can have traditional genuine leaded lights and can also have stained glass designs. Double glazed units can be manufactured with clear glass or decorations can be applied such as rectangle or diamond leaded, coloured film, horizontal or Georgian applied bars. Obscured glass is also available in a variety of options.

Domestic External


W20 hot rolled steel profiles are used mainly to manufacture steel doors and full height screens.

The glazing bar used on W20 doors and screens is the slimmest available true glazing bar at just 28 mm wide. The majority of steel doors and screens on social media will be manufactured from this profile.

Designs can be very flexible and so clients are able to specify door screens  that have opening windows within them as well as the doors. The frames can be bent on elevation to create arches or on plan to create Art Deco style fenestrations. Raked head doors and windows can also be manufactured.

Some members offer a version of this profile that conforms to BFRC energy ratings so that they can manufacture windows as well.


W30 hot rolled steel profiles are an evolution of the W20 profiles and were specifically designed so that windows could be manufactured in ‘multilight’ designs without the need for coupling bars that would thicken the profiles. This system was also designed so that it conformed with modern thermal requirements to Part L building regulations for domestic windows and so achieves ‘BFRC’ energy ratings.

This system is particularly suited when replacing existing single glazed steel windows which may no longer warrant keeping.

They are double glazed, galvanised and powder coated and so minimum maintenance is required.

The windows can be specified with a variety of hinge, handle and peg stay choices. Where customers require additional security, these windows can be specified with concealed multi locking systems.

The double-glazed units can be manufactured with clear glass or decorations can be applied such as rectangle or diamond leaded, horizontal or Georgian applied bars. Obscured glass is also available in a variety of options.


W40 hot rolled steel profiles have been specifically designed by the SWA for the SWA members.

They provide even greater flexibility in terms of maximum manufacturing sizes and can accommodate thicker double or triple glazed units.

Doors manufactured using W40 profiles with triple glazing can achieve a 1.5 W/m2K thermal rating.

Some customers specify this system due to it being able to accommodate up to 32 mm glazing and so it can be specified with acoustic glass which may be desirable when the property is backing onto areas with persistent noise issues.

Multi-locking windows and doors are available in this system.

Specifier’s guide

The specifiers guide is a technical document published for architects and designers. It contains our members range of products, section details and technical specifications.

Find a member

Our members are more than happy to discuss a project with you and then provide pricing, design details and specification criteria. Please click on the link above to locate a manufacturer or installer that can carry out a project in your area.