Designed to look and operate as a traditional cord & weight box sash window, but with the benefit of being able to open the whole assembly inwards as a unit. Is also available with spiral balances if applicable.

The concept is simple. The inner part of the box frame is split diagonally from the outer and then hung on it like a door. As the outer parts of the outer frame are normally hidden by the reveal, all parts that require cleaning, painting or maintenance are moved into the room when the box is open.

The advantages of this arrangement are as follows.

It allows the outside of the window to be cleaned from inside the room, thus meeting all the current Health & Safety regulations regarding cleaning windows at height.

Similarly, it allows redecoration and maintenance, such as replacing the glass, from inside the room.

In the open inwards position, free access is available to the weights and cords making adjustment easier and quicker. Only if the cords are to be replaced is removal of the sash necessary.

In the event of fire it provides an opening more than twice that which would be available by merely opening a sash. For small windows this may well be a critical factor in meeting Building Regulations.

Construction is by traditional joinery methods and does not involve special hinges or anything unusual that can cause trouble, or may not be available in years to come.

Glazing can be anything from 4mm single to 24mm double, or even thicker for triple, if required.

Widely spaced secondary glazing, for extra acoustic insulation, can be incorporated in the window assembly without departing from the traditional look.

When required Trickle Vents can be discretely incorporated in the frame head (if low enough to be reachable), or the bottom rail of the lower sash, without their inclusion being obvious from the outside. On the inside the diffuser will be obvious on the bottom rail, less so when in the head.

This design provides an economic solution to the problem of providing a window that has all the grace and elegance of the traditional box sash, can be fitted as a direct replacement for existing, even in listed building, but meets all current Health & Safety and Building Regulations.