A space is understood when it comes into use: its function, atmosphere, physical qualities and the experience it offers
An interior may appear perfectly resolved on a plan or in a rendering, yet behave very differently once it is put into use. People introduce movement patterns, timetables, noise, objects, maintenance and needs that the final image does not show. That is why designing a space requires linking programme, circulation, atmosphere and materiality with something far less static: the life that will take place within it.
The project seems finished until someone opens the door
On paper or on screen, an interior architecture plan conveys impeccable order. Partition wall thicknesses are defined, dimensions line up, doors open at the exact angle, and the furniture sits neatly aligned on a clean surface, with no visible cables or coats draped over the backs of chairs. The digital image freezes that ideal moment: balanced light streams in through the window, the materials retain their pristine texture, and the composition suggests a still harmony.
However, the plan describes the intended space. Use reveals the actual space.
The moment a space is put into use, a second layer of information begins to overlay that initial geometry, almost as if a second invisible layer were being drawn. Within a few weeks, a chair is found to have been moved from its original position every morning because someone needs to avoid an annoying glare; a desk ends up rotated by fifteen degrees to prevent the screen from being visible to anyone walking down the corridor; a makeshift power strip appears under a desk because the socket was hidden behind a skirting board; a blind remains permanently lowered to reduce glare on a work surface; someone attaches a paper sign with adhesive tape because the main entrance is confusing; two pedestrian routes repeatedly collide at an unexpected narrowing, and the floor varnish or the paint on a corner begins to wear away at an unusually rapid rate.
Faced with these everyday alterations, the superficial temptation is to dismiss them as oversights or a lack of discipline on the part of those who inhabit the space. They are not. They constitute evidence of use that allows us to discern, with surgical precision, the gap between the designed space and the lived space.
Interior design focuses on the organisation, experience and conditions of interior space, combining technical and intuitive decisions.It does not involve simply adding a decorative shell to a pre-existing structure, but rather rigorously anticipating how that space will function when subjected to the stresses, the presence of people and the rhythms of human activity.
Before drawing rooms, one must understand what needs to happen inside them
When tackling a spatial commission, the initial impulse is often to demarcate rooms, draw up partition plans and assign them a generic functional label: classroom, office, bedroom, dining room. Reducing the start of a project to a list of rooms strips the discipline of its true operational complexity.
In professional practice, the programme of requirements translates people, activities and needs into spatial conditions that the project must be able to address. It is not a static list of square metres; it is a detailed analysis of dynamic variables: which groups will be present, what tasks they will carry out throughout the day, how frequently and simultaneously these will take place, what levels of visual and acoustic privacy each activity requires, what storage requirements the equipment entails, and what technical requirements for ventilation, data systems or climate control apply to every cubic metre.
Let us consider, for example, an open-plan space of forty square metres. It might be designed to accommodate the focused work of four professionals in the morning, transform at midday into a meeting table for eight diners or participants, host an open presentation session for fifteen attendees in the mid-afternoon, and, simultaneously, require the permanent and accessible storage of technical equipment, coats and cabling.
Are we designing a single room, or four different operational modes that must share the same building envelope? Two spaces with identical floor areas may require radically different solutions depending on their architectural programme. Designing an interior involves structuring the physical conditions so that these transitions occur seamlessly, anticipating from the very first sketch how the routines, waiting times and shifts in activity levels of each occupant overlap.
Circulation is not the space left over between the furniture
There is a common mistake when conceiving the layout of spaces: treating circulation as if it were a geometric remnant, a passive strip that simply surrounds the main furniture.
People do not move like abstract vector lines on a grid. They enter, come to an abrupt halt when crossing a threshold to get their bearings, wait standing whilst maintaining a polite distance from the person opposite, carry bulky items, turn on their heels, pass shoulder to shoulder, seek out a sheltered corner for a private conversation, or need to dodge fast-moving streams of people. For this reason, pedestrian flow is not merely the presence of a corridor; it represents the very structure of the relationship between the activities coexisting within the space.
A conventional technical plan can accurately depict a row of tables, a service counter and two passage doors. What that two-dimensional representation does not automatically capture is the impact of an unexpected queue of seven people waiting their turn, the turning circle of a pram or a wheelchair, the manoeuvres of cleaning staff pushing a service trolley, or the moment when someone pulls a chair away from a table and completely blocks an evacuation or transit route.
Furniture takes up floor space. Activities take up space
A chair placed next to a table takes up barely half a square metre. The same chair when occupied—with a person leaning back, standing up or pushing it backwards to get out—takes up more than double that area and projects a zone of influence that restricts the movement of anyone passing behind them.
This is where the importance of space planning lies. Space planning examines how to organise zones, relationships and circulation routes so that the intended activities can coexist efficiently. This planning of spaces assesses both anthropometric dimensions and interpersonal comfort distances, universal accessibility and the intuitive clarity of pathways.
When spatial design skilfully resolves these interrelationships, visitors do not need explanatory signage to know where to go: the modulation of ceiling heights, the hierarchy of passage widths, the visual openings and the layout of the spaces guide movement naturally and safely.
Atmosphere is not a filter applied at the end
In the popular imagination, the notion of atmosphere is often associated with vague and aspirational adjectives: ‘warm’, ‘cosy’, ‘relaxing’ or ‘stimulating’. It is often assumed that it is a stylistic patina added to the project in its final phase through a fashionable colour palette or a selection of cushions and decorative light fittings.
The reality of design is far more rigorous. An atmosphere is not a filter applied to a room; it emerges from the simultaneous physical interaction between natural and artificial light, the properties of materials, the scale of proportions, acoustic behaviour, radiant temperature, smell, the density of elements and the visual relationship with the external environment.
Attributing universal moods to isolated decorative decisions — asserting without nuance that a specific colour calms any individual or that the use of a particular surface finish automatically generates a sense of well-being — constitutes a simplification that bypasses the scientific and design method. Environmental comfort is achieved by regulating tangible phenomena: controlling glare through lighting design, ensuring acoustic privacy between adjoining rooms, selecting colour temperatures in line with the circadian rhythm, and managing scale so that a space neither overwhelms nor suffocates its occupants.
Many sensations arise from entirely physical conditions
The atmosphere may be perceived intuitively, but many of the conditions that produce it are entirely physical. The sense of well-being or discomfort evoked by a room rarely stems from a subjective whim; it almost always responds to measurable environmental parameters.
Consider the design of a reading room or a small-scale library where the aim is to foster concentration and silence. This is not achieved simply by painting the walls in neutral tones. It is achieved if the design physically separates noisy entry points from the study tables; if it incorporates cladding with sound absorption coefficients calculated to prevent reverberation from amplifying the murmur of conversation; if it mechanically insulates against the hum of air-conditioning ducts; if it provides direct interior lighting with appropriate lux levels and shadow control to prevent visual fatigue; and if it calibrates the ventilation so that the build-up of CO₂ does not induce drowsiness in the middle of the afternoon.
What the visitor experiences as an intangible sense of serenity is, in reality, the result of strict technical coordination between architecture, building physics and sensory design.
Materials come to life once the rendering is complete
In the virtual rendering environment, a material is a two-dimensional texture applied to a three-dimensional polygon. It weighs nothing, does not absorb grease, does not wear away from the continuous abrasion of rubber soles, does not creak, does not accumulate dust in its joints and does not change colour under prolonged exposure to ultraviolet radiation.
In real life, architectural materiality is defined by what the material physically does within the space and by how it responds to daily contact with bodies. Designing with materials is not simply compiling a sample book of finishes juxtaposed on purely visual grounds. It involves asking essential technical questions:
- What is the light reflectance coefficient of this surface, and how will it affect the overall contrast of the space?
- Does its porosity absorb sound waves or turn the room into an unmanageable echo chamber?
- Is the surface cold or warm to the touch when the skin is in prolonged contact with it?
- Does it have the necessary slip resistance to prevent falls if it becomes damp?
- How does it withstand standard disinfectants and cleaning products?
- How does it change over time: does it acquire a dignified patina through use, or does it deteriorate irreversibly at the edges?
It is in the construction details that the material’s true worth is revealed. The joint between two floor coverings of differing hardness, the junction between a vertical wall and the floor without a skirting board, the protection of a sharp edge in a high-traffic area, or the gap allowed for thermal expansion in joinery – all determine whether a space will age with dignity or develop cracks, flaking and stains within a few months of opening. Durability and maintenance are not secondary issues left to the property manager; they are fundamental decisions in the interior design project.
A space may function perfectly at ten in the morning and fail by seven in the evening
Time is one of the most relentless forces in spatial design. An interior is not inhabited in a static state: the stresses it undergoes constantly change over the course of hours, days and seasons.
At ten o’clock in the morning, a workspace may enjoy optimal low-angle natural light, a moderate level of occupancy, stable temperatures and a suitable acoustic environment. At seven in the evening, that same space may overheat due to direct sunlight on west-facing façades, accumulate excessive heat caused by an increase in the number of occupants and electronic equipment, become unbearably noisy due to the influx of telephone calls, and require artificial lighting zones that the project did not provide for in its original electrical installation.
This daily variability demands that the issue of flexible spaces be addressed without resorting to simplistic clichés. Designing with spatial flexibility does not mean fitting castors to all the furniture or conceiving a completely neutral and indeterminate space where, supposedly, ‘anything can happen’. When a space is not designed for anything in particular, it ends up being of little practical use for almost anything.
Flexibility does not mean that anything can happen anywhere, but rather that the design knows what changes it needs to be able to accommodate. Intelligent flexibility is precise and well-defined: it provides for accessible technical areas, incorporates built-in storage systems that free up floor space in a matter of minutes, defines movable partitions with effective sound insulation to separate one use from another, and scales the installations so that they can absorb peaks in demand without compromising environmental comfort.
When people adapt the space, the design receives a response
Throughout a building’s lifespan, its occupants engage in a constant process of adaptation. Far from being an assault on the purity of the design, this phenomenon constitutes the most honest feedback the project can receive regarding its actual performance.
When a user instinctively drags an armchair towards a window opening, they are revealing an instinctive search for natural light, visual contact with the outside, or a more pleasant temperature than that found in the centre of the room. When staff at a centre wedge a fire door open to keep it permanently open, they are highlighting a tension between safety compartmentalisation and the fluidity of daily movement. When an improvised carpet, not originally planned, appears in a lobby, the occupants are trying to solve an unbearable acoustic reverberation or prevent dirt from entering – something the exposed concrete floor immediately reveals.
The question that must be asked in such situations is not whether the user is in the wrong, but rather: does the alteration work against the space, or does it enable the user to truly make it their own? A rigid layout that does not allow for individual adaptation fails on a human level; a space that tolerates and embraces personalisation without losing its structural coherence demonstrates design soundness.
In advanced international practice, this systematic confrontation between planning and reality is addressed through post-occupancy evaluation. This methodology investigates, in a structured manner, how buildings perform once occupied, measuring energy consumption, actual noise and light levels, user satisfaction and actual movement patterns. Its conclusions do not invalidate the project; rather, they provide feedback, transforming the experience of occupation into critical knowledge for future interventions.
A real-life case: designing for living, coexisting and feeling at home
Understanding how programme, materiality and everyday use interact is clearly evident in projects where human needs are particularly sensitive. A telling example is the Final Year Project entitled ‘New Chapter’, developed by Ramón Rosales López at UDIT.
The proposal addresses the transformation of an existing dwelling into a collective transitional residential facility for young people leaving care who have reached the age of majority. In this context, the programme could not be resolved through a generic residential layout nor with the sterile coldness of a supervised care centre. The project had to balance, with extreme precision, two seemingly opposing needs: the autonomy and privacy required for each individual’s personal recovery, and the communal living necessary for learning to share adult life.
The spatial solution clearly structures the different levels of use. The proposal rigorously distinguishes between private rooms for personal rest, the everyday communal living areas geared towards domestic socialisation (shared kitchen, lounge, dining room) and a multi-purpose basement intended for training activities, workshops and group meetings.
Far from resorting to superficial rhetoric about comfort, the project translates this objective of deinstitutionalisation into very specific material and environmental decisions. The use of timber, the design of warm and predominantly indirect interior lighting, the use of continuous textiles, and the controlled scale of the furniture elements are all deliberately intended to distance the environment from the impersonal image of a public care home. Every material detail, every visual filter between the corridor and the private room, and every seating area is carefully designed to create a setting of physical and psychological security where residents can rebuild their daily routine and truly feel at home.
What does it mean to study Interior Design when you begin to view spaces in this way?
Learning to design from this perspective entails a radical transformation in the future designer’s way of seeing. Those who enter this discipline drawn solely by the formal appeal of the images soon discover that true professional rigour lies at the intersection between the technical and the sensory.
In UDIT’s Official Bachelor’s Degree in Interior Design — and in its bilingual international programme, the Official Bachelor’s Degree in Interior Design —the educational experience is not limited to modelling aesthetic forms or mastering computer-aided design tools. It involves learning to integrate, within a single project process, people’s complex needs with the geometric organisation of space, the physical behaviour of materials, acoustics, lighting calculations, construction details and the applicable technical regulations.
For those seeking advanced specialisation in the management of large-scale or functionally complex projects, the Official Master’s Degree in Interior Design delves deeper into this holistic approach, preparing professionals to lead spatial interventions in the corporate, commercial, residential and care sectors based on a rigorous analysis of the life cycle and the user experience.
Designing an interior is no longer merely an exercise in isolated aesthetic composition, but has become a discipline capable of actively transforming the way we work, interact, learn and inhabit the built environment.
An interior is not finished when it appears to be finished
On the day the building work concludes, the tradesmen pack away their tools and the keys are handed over to a pristine space; this is not the end of the project. We are merely witnessing the end of its physical construction.
The interior begins its true existence the moment the first occupants enter, place their belongings on the tables, switch on the lights, walk across its surfaces and start to navigate their daily lives within the conditions the designer anticipated on paper.
Neither the most hyper-realistic rendering nor the most exhaustive floor plan can fully capture the reality of a space. The quality of a design is not measured by its ability to generate an eye-catching photograph on social media, but by the quiet reliability with which it organises circulation, dampens noise, withstands the wear and tear of time, and supports the activities of its inhabitants with aesthetic sensibility and efficiency.
Learning to look at an interior changes when you stop asking yourself solely how it looks and start observing what it allows you to do, how you move through it, how it feels and what happens to it as time goes by. Explore UDIT’s Interior Design programme and discover how to learn to design spaces from all these perspectives.
