Central or lateral structure: how to choose the ideal configuration for your open staircase

When deciding to install an interior open staircase, one of the aspects to evaluate concerns the type of supporting structure. Open staircases can in fact be made with a central structure or with a lateral structure.

In this guide we analyse the distinctive characteristics, advantages, and peculiarities of both configurations, providing you with all the necessary elements to better understand which of the two solutions optimally meets your space, style, and functionality requirements. To make our guide even more concrete, we also present two Rintal solutions that perfectly embody these two design philosophies: Knock, the staircase with central structure that combines minimalism and solidity, and Composity, the staircase with lateral structure that offers compositional versatility and great aesthetic impact.

Table of contents

• Open staircases: elegance and brightness for interior spaces
• Central structure or lateral structure
• Open staircases with lateral structure
• When to choose a staircase with lateral structure
• Composity: the staircase with lateral structure
• Open staircases with central structure
• When to choose a staircase with central structure
• Knock: staircase with central structure
• Conclusions: your ideal staircase

Open staircases: elegance and brightness for interior spaces

Open staircases represent an increasingly appreciated design choice for those who wish to combine functionality and refined aesthetics in domestic environments. These structures are characterised by the absence of closed risers between steps, creating a light visual footprint and an effect of great openness that makes them perfect for enhancing and illuminating any type of interior space.

Unlike traditional masonry staircases, completely closed and more massive, open staircases feature an exposed supporting structure that supports the treads while leaving the passage of light free. This very peculiarity constitutes their most appreciated distinctive element: the ability to let natural light flow through the entire structure, without panels or closed elements between one step and another obstructing its path. The result is a brighter, airier, and visually more spacious environment, where light diffuses freely creating evocative plays of light and shadow that enrich the home's atmosphere and enhance its contemporary character.

This type of staircase proves to be an ideal solution for multiple residential configurations:

• Habitable mezzanines, where it's essential to maintain visual lightness and not weigh down the space
• Lofts and open spaces, environments that require visual continuity, spaciousness, and maximum brightness
• Two-level homes, where the staircase connects living area and sleeping area without creating visual barriers, preserving a strong sense of openness
• Connections between living area and sleeping area, to create a harmonious and elegant transition between environments
• Attics and penthouses, contexts where every source of natural light becomes an element of great value

To proceed with choosing your open staircase, one decision to make is: where to position the supporting structure that holds the treads?

Central structure or lateral structure

Open staircases are divided into two main categories based on the position of the supporting structure:

• Staircases with lateral structure (stringer): they have two vertical stringers positioned at the sides of the treads. The treads are contained and supported between these two parallel load-bearing elements.
• Staircases with central structure: they have a structure positioned in the centre under the treads. The treads attach to this central spine, creating a particularly light suspended effect.

This structural difference affects several factors such as aesthetics and footprint; let's examine the characteristics of each type in detail.

Open staircases with lateral structure

Staircases with lateral structure feature two vertical stringers (also called carriages) that run parallel along the entire flight. The treads are fixed between these two load-bearing elements, creating a solid and defined structure.

Advantages of staircases with lateral structure

Open staircases with lateral structure represent one of the most appreciated solutions in interior architecture for their balance between structural solidity and visual lightness. Let's examine in detail the main advantages of this configuration:

• Uniform treads: all treads maintain the same shape and depth along the entire flight. The staircase can be equipped with a landing or a three-step turn if deemed necessary.
• Refined aesthetics: the lateral stringers create an elegant and contemporary visual effect, transforming the staircase into a true furnishing element that enhances and characterises the environment. The structure becomes an integral part of the home's design.
• Design versatility: staircases with lateral structure adapt with great flexibility to different needs: they can be designed in straight version or with quarter-turn (L) or half-turn (U) configurations, integrating perfectly into different domestic floor plans. Furthermore, this type allows choosing between different widths, materials, and finishes, proving suitable for both modern and more traditional or classic contexts.

Learn more on the dedicated page for open staircases with lateral structure.

When to choose a staircase with lateral structure

Open staircases with lateral structure are the ideal choice if:

• You have sufficient space: widths start from 74 cm and reach up to 94 cm. If you have an opening in the floor slab with these dimensions, you can make the most of the advantages of the double structure.
• You seek maximum comfort: uniform treads and superior stability make these staircases perfect for daily use. If you're connecting main living areas, lateral structure is the most comfortable choice.
• You want a staircase as a furnishing element: clean lines and suspended effect transform the staircase into a true protagonist of the space. If the environment allows it, the more marked visual presence becomes a focal point of the design.

Composity: the staircase with lateral structure

Composity is the open staircase with lateral structure born from collaboration with Giugiaro Architettura and the Rintal Stair System philosophy; Composity represents the excellence of Italian Smart Design.

Exclusive design

The clean and essential design of Composity conceals advanced technical solutions. The total absence of visible screws on the external part of the structure is the distinguishing feature. The fixings of treads and railing are completely integrated, ensuring clean lines without compromising safety and strength.

Consult the dedicated page for Composity.

Open staircases with central structure

Staircases with central structure develop on a series of modules positioned at the centre of the flight. The treads attach to these central modules, creating an even lighter effect compared to lateral structure.

Advantages of staircases with central structure

Open staircases with central structure represent the ideal solution for those seeking maximum visual lightness and installation versatility. This type of staircase is particularly suitable for reduced spaces or situations where minimising structural footprint is essential. Here are the main advantages:

• Visual lightness: the central structure creates an even more pronounced "suspended" effect compared to double lateral structure. The central modules minimise perceived footprint, ideal if you want to maintain maximum visual transparency in the environment.
• Wide range of widths: available from 65 cm to 95 cm, they allow choosing the perfect dimension for your space. This versatility is difficult to find in other models.
• Adaptability: the modular system allows precise adjustments even during installation, perfect for renovations where stairwell measurements are binding.

Learn more on the dedicated page for staircases with central structure.

When to choose a staircase with central structure

Open staircases with central structure are the ideal choice if:

• You want to maximise brightness: if the staircase is positioned at a strategic point for natural light diffusion, the central structure maximises this benefit without visual barriers.
• You seek versatility: the wide range of widths (from 65 cm to 95 cm) allows adapting the staircase to very different contexts. From minimum opening to comfortable passage, you always have a modular solution.

Knock: staircase with central structure

Knock is our open staircase with central structure designed by Giugiaro Architettura. This model represents the perfect balance between Italian design, structural solidity, and advanced modularity.

Design and innovation

Knock combines a painted steel structure with the possibility of integrating an LED lighting system into the structure, creating a unique scenic effect. The structure is composed of modular elements joined by a patented anchoring system that guarantees resistance.

Learn more on the dedicated page for Knock.

Conclusions: your ideal staircase

The choice between central structure and lateral structure is not about which staircase is better in absolute terms. Both solutions guarantee solidity, safety, and high construction quality.

The final decision is above all a matter of available dimensions and aesthetic result you want to achieve in the space.

Lateral structure generally requires more generous widths and becomes a more present architectural element, capable of characterising the environment. Central structure, instead, allows greater freedom in measurements and offers a lighter and more minimal visual impact.

In this sense, Composity and Knock represent two different interpretations of the open staircase:

• Composity, with lateral structure, is ideal when space allows it and you want a protagonist staircase, with decisive and compositional design.
• Knock, with central structure, adapts more easily to variable dimensional contexts and to those seeking an essential visual mark.

Therefore, there is no "superior" solution over the other: the most correct choice arises from the balance between stairwell measurements, environment style, and role the staircase must have within the project.

In both cases, choosing a Rintal staircase means integrating into the space a design object that combines functionality, style, and design freedom. Our open staircases are designed to adapt to different architectural contexts, offering modular and customisable solutions that transform into true protagonists of the space.