A few vocabulary terms

Headroom

It is the distance between each step and the ceiling. To be comfortable, it must never be less than 2m at any point of the staircase. It also determines the length of the stairwell opening.

Stair width

It refers to the width of the steps of a staircase, i.e. the passage width. It varies depending on the type of staircase.

Japanese-style staircase

The Japanese-style staircase is characterised by cut steps that do not fully overlap. The use of this type of staircase, despite its steep pitch, is therefore made easier by a comfortable step depth and a very instinctive ascent.

Loft ladder

A loft ladder is chosen for its ability to fold away and disappear completely from view
Several types of loft ladder exist:

• telescopic ladders with an accordion-style extension mechanism (generally in aluminium);
• sliding ladders made up of several segments that slide down to the floor (in wood and aluminium);
• folding ladders made up of segments (2 or 3) that unfold to reach the floor.

Going

It is the depth of the step measured nose to nose along the line of travel. It is often confused with the tread, which is the total depth of the step. The going is determined using Blondel's formula: 2H + G = 59 to 64, where H represents the step height.

Stringer

a stringer is an oblique upright that supports the steps. It is classically located under the end of the steps; when it is central, it is called a spine stringer.

Balanced step

The steps begin to turn within the straight flights, allowing for wider treads in the turning section.

Winding step

In the straight flights, they remain perpendicular to the stringers; in the turning section, they become winding.

Stairwell opening

It is the void created in the floor to allow the staircase to pass through. Its shape varies depending on the type of staircase and the minimum headroom required for comfortable use.
A determining factor in the choice of staircase