Internal Staircase: Everything You Need to Know About Measurements, Costs and Permits
Internal staircases: complete guide to types, dimensions, costs and regulations. Discover how to choose the internal staircase best suited to your needs.
Internal staircases represent much more than a simple connection between the floors of a home: they are an architectural element that defines the style of the house, optimizes spaces and can become the protagonist of interior design.
Whether you are designing a new construction or renovating an existing environment, choosing the right staircase requires attention to several factors.
In this guide you will discover everything you need to know about internal staircases: from the available types to the most common materials, from indicative prices to recommended dimensions, up to practical advice for making the perfect choice for your home.
Table of contents
Internal staircases: what to know before choosing
The design and installation of an internal staircase require a preliminary analysis of fundamental technical and bureaucratic elements to ensure safety, functionality and regulatory compliance
- Analysis of available space: before proceeding with the choice, it is essential to accurately measure the horizontal space and vertical height of the environment intended to house the staircase. These data will determine which type of staircase is most suitable and whether structural interventions are necessary
- Calculation of floor-to-floor height: the exact distance between the two levels to be connected is essential to determine the number of steps needed and the overall dimensions of the staircase. An accurate calculation avoids problems during installation and ensures compliance with safety regulations
- Regulatory verification and permits: before proceeding with the purchase, it is necessary to verify which municipal authorizations are required based on the type of intervention. Regulations vary according to the municipality of residence and the type of work to be carried out
- Choice of type: there are different solutions for internal staircases, each with specific characteristics. Open staircases, available with central structure or lateral, offer lightness and modernity, spiral staircases optimize reduced spaces, space-saving staircases are ideal for secondary connections, while retractable staircases represent the solution for sporadic access to attics and lofts
- Budget definition: establishing in advance how much you intend to invest helps to navigate between the different options of materials, finishes and levels of customization available on the market
- Evaluation of usage needs: the frequency of use and the characteristics of users (presence of small children, elderly people or people with reduced mobility) influence the choice of staircase type, step material and the presence or absence of handrails
Dimensions and minimum spaces required for internal staircases
Designing a staircase requires attention to spaces to ensure comfortable and safe use:
- Length: the actual length depends on the floor-to-floor height and must respect the limit of maximum 15 steps per flight
- Width: the minimum width is 80 cm for private main staircases. In environments with limited space that need a secondary staircase, it is possible to opt for space-saving staircases, where the staircase width is often less than 80 cm. For these situations, Rintal offers space-saving staircases starting from 61 cm width
- Height and number of steps: the rise represents the vertical height of each individual step and must be between 17.5 and 22.5 cm to ensure a comfortable ascent. A rise that is too high makes use tiring, while a rise that is too low excessively increases the number of steps needed
- Space-saving solutions: when space is limited, the spiral staircase is an excellent choice. We recommend the 160 cm diameter because it is the most comfortable and walkable. Diameters of 140 cm and 120 cm are also available for more compact contexts. To accommodate situations where exemptions are granted at a local level, Rintal also manufactures spiral staircases of compact dimensions, up to 105 cm
- Compliance with local regulations: in addition to national parameters, each municipality may have specific building regulations with more restrictive requirements. It is always advisable to consult the municipal technical office before proceeding with the project
- Importance of professional consultation: relying on a surveyor, architect or engineer guarantees a tailor-made project that takes into account the specific characteristics of the property, optimizes available spaces and respects all current regulations regarding safety and accessibility
Building permits for internal staircases: when are they mandatory
The construction or modification of an internal staircase may require different administrative authorizations based on the extent of the intervention and the urban planning regulations of the municipality of residence.
In general:
- Ordinary maintenance and replacement: simple replacement interventions of an existing staircase with a new one, without modifications to the load-bearing structure or space distribution, generally fall under ordinary maintenance and do not require building procedures.
- Structural modifications or increase in floor space: require the submission of procedures such as CILA (Certified Communication of Work Commencement), SCIA (Certified Report of Work Commencement) or PdC (Building Permit).
- Mandatory verification with the Municipality: each municipal administration may have different requirements, so it is always recommended to inquire in advance.
Types of internal staircases: features and advantages
There are different types of internal staircases, each with specific characteristics that make it more or less suitable for certain residential contexts. Knowing the differences will help you identify the ideal solution for your needs.
Open staircases with central structure
Open staircases are a classic and versatile solution for residential environments. Their open structure makes them visible from the surrounding environment, transforming them into true furnishing elements. They can be made in different materials and finishes, and adapt to straight configurations or with one/two turns. This type enhances space, maintains brightness and offers a light and modern effect.
Learn more on the page dedicated to open staircases with central structure.
Open staircases with lateral structure
Open staircases with lateral structure represent one of the most appreciated solutions in interior architecture for their balance between solidity and visual lightness. The load-bearing structure, positioned laterally with respect to the steps, allows obtaining a clean and essential line that enhances the surrounding space.
This type of staircase stands out for its great versatility: it can be designed with different widths, materials and finishes, easily adapting to both modern environments and more traditional contexts
Discover more on the page dedicated to open staircases with lateral structure.
Spiral staircase
Compact and elegant, the spiral staircase is ideal for connecting two levels in environments with reduced square footage, such as attics, lofts or small apartments. Thanks to the variety of styles and finishes available, it easily adapts to both modern and classic contexts, becoming a true furnishing element.
Learn more on the page dedicated to spiral staircases.
Space-saving staircase
Space-saving staircases are designed to solve housing needs in contexts where spaces are reduced, without sacrificing comfort and functionality. Thanks to their compact conformation, they represent the ideal solution for connecting lofts, attics, small apartments or environments with limited square footage. One of the main characteristics is the staggered or alternating tread, which allows reducing the depth footprint while still maintaining a comfortable ascent
Discover more about space-saving staircases.
Cost of an internal staircase
The cost of an internal staircase can vary significantly based on several factors, including type, materials and dimensions.
The main factors that determine the price of an internal staircase are:
- Staircase type: spiral, space-saving, with central or lateral structure
- Dimensions: staircase width and height
- Finishes and color: customization of steps and handrails
General cost overview, prices recorded in November 2025
- Spiral staircases: from €1300
- Open staircases: from €2000
- Space-saving staircases: from €700
For a more precise idea visit our Rintal catalog.
How to calculate the measurements of an internal staircase
Calculating an internal staircase is a fundamental phase in design, because safety, comfort and compliance with building regulations depend on it. It is necessary to carefully evaluate elements such as rise, tread, inclination and staircase width.
To help you clarify formulas, standard measurements and practical rules to follow, we have dedicated a complete article that will guide you step by step: How to calculate an internal staircase: formula, standard measurements and practical advice.
How to choose the perfect staircase for your home
Choosing the perfect internal staircase means finding the ideal balance between functionality, aesthetics and the specific needs of your home.
Each type of staircase responds to different needs: spiral staircases maximize available space while maintaining a strong visual impact, open staircases with lateral or central structure offer linearity and contemporary elegance, while space-saving staircases represent the most compact solution for environments with dimensional constraints.
Browse our catalog of internal staircases and discover the solution best suited to your needs, with the assurance of a certified and long-lasting product.