Horizontal sliding windows, available with two or more panels, are extremely versatile. Sashes slide within the frame allowing easy access to the outer windows without interfering with curtains, blinds or ceiling bulkheads. Units can be linked with coupling sections allowing both large and ribbon windows to be successfully treated.

Vertical sliding units are ideal for treating traditional sash windows and are particularly suited to the refurbishment and upgrade of historic buildings. The sliding sashes are attached to spring balances and are easily opened to any position for ventilation.

Hinged casement windows allow full and easy access to the outer window. They are neat and unobtrusive with no transoms or mullions to impede the view and will generally provide higher levels of security. This style of secondary glazing is appropriate for doors but there must be clearance for pelmets, curtains and ceiling bulkheads.

Lift out units offer a practical treatment for windows which are rarely used or as side or over lights in combination with other windows. The glazed panel is lifted out of the frame when access is needed for cleaning or maintenance.

Fixed panels are generally used as side or over lights in combination with other windows and are also extensively used to treat curved windows. They should never be applied to a window requiring access for escape purposes. They are also used as observation windows in laboratories, clean rooms, control rooms and recording studios.

Many older buildings have shaped or curved windows and these need to be treated sympathetically. Shaping involves the use of irregular angles and units with more than four sides. It is possible to shape horizontal sliding units, hinged casements, lift out units and fixed panes. Windows with arched heads can be accommodated by vertical sliding units and fixed or hinged casements and bull’s eyes with fixed or Lift out panels. Curving on plan is achieved with fixed panels or hinged casements.