Interior Design: what it is, functions and examples

You walk into a coffee shop and something grabs you. It's not just the coffee, or even the background music. It's the space: the light falls softly on the wooden tables, the route to the bar flows smoothly and every corner seems designed to make you feel good. That's no coincidence. It's interior design: the discipline that transforms empty spaces into places that work, excite and improve the lives of the people who live in them. 

If you've ever looked at a space and thought "this could be so much better", if you notice how the furniture in your home is arranged, or if you wonder why some places make you feel instantly comfortable while others make you feel uncomfortable without really knowing why, interior design is probably your thing. In this article you'll find out what an interior designer actually does, what their specific functions are and what kind of projects they work on every day. And if after reading this article you decide you want to take the professional leap, the UDIT Bachelor's Degree in Interior Design offers you a complete curriculum that prepares you from day one to design real spaces. 

What is interior design? 

Interior design is the discipline that projects and transforms interior spaces - whether new or existing - to solve real people's needs. It is not just about choosing beautiful colours or tasteful furniture. An interior designer thinks about how you use the space, how you move through it, how the light enters, what temperature is needed, what the atmosphere sounds like and what it feels like to be there. 

It works with concrete elements: natural and artificial light, room layout, floor and wall materials, furniture, colours, acoustics, ventilation and integrated technology. But it also works with something more intangible: the atmosphere, the emotion and the identity of the space. A good interior design project makes a place work better, feel better and tell something about the people who live there. 

The five pillars of interior design

Every interior design project is built on five essential pillars that define the final quality of the space: 

Function. The space has to fulfil its purpose without friction. A kitchen should allow you to cook in comfort, a bedroom should invite you to rest and an office should facilitate concentration. If the space doesn't work, nothing else matters. Functionality is non-negotiable. 

Comfort: temperature, acoustics, ergonomics of furniture and quality of light must be balanced. A space can look beautiful in a photo, but if it is uncomfortable for the body, the project has failed. Comfort is felt, not seen. 

Identity: Each space must communicate something. It can be the personality of the person who inhabits it, the values of a brand or the atmosphere of an experience. Identity is not imposed; it is built decision by decision, material by material, colour by colour. 

Sustainability: Today, it is not enough for a space to function well. It must do so without exhausting the planet's resources, choosing responsible materials, reducing waste and thinking about the entire life cycle of the project. Sustainability is both ethical and aesthetic. 

Accessibility: A well-designed space is navigable and usable for all people, regardless of mobility, age or sensory abilities. Inclusive design is not an extra: it is spatial quality that always adds up. 

What does an interior designer actually do? 

Here comes the question on everyone's mind: what does the day-to-day work of an interior designer consist of? The short answer is that he or she transforms real problems into liveable solutions. The long answer is that they do much more than choose sofas and paint walls. 

An interior designer listens to the client, asks questions, measures the space with millimetre precision, detects critical points, sets out a clear concept, draws up technical plans, chooses materials, designs the lighting, coordinates with installers and builders, controls the work and ensures that everything is delivered as planned. It is a mix of overflowing creativity, rigorous technique and efficient management. 

The essential technical skills

Measure and draw the space. It all starts with an accurate survey: taking measurements, drawing plans to scale and modelling the space in three dimensions. Without a good base of measurements, the rest of the project floats in the air. This phase defines the feasibility of all subsequent decisions. 

Thinking about the layout, deciding where each use goes, how the rooms are connected to each other, where people circulate and how to make the most of every square metre available. This is the phase where the game is won or lost. A good layout solves 80% of the problems before the first material is chosen. 

Designing the lighting: light is not a decorative addition. It is project material. Well-thought-out light enlarges small spaces, creates intimacy, guides the eye and improves physical and emotional well-being. An interior designer works with several layers of light: general light for visibility, spot light for highlighting and ambient light to create atmosphere. 

Choosing materials: Each material has a specific behaviour, a proven durability, a particular maintenance and a predictable ageing. Knowing which to put where - and why - is what separates an amateur project from a professional one. There is no such thing as good or bad materials, only good or bad choices. 

Document the project: No project is finished until it is documented. That means clean technical plans, clear memories, detailed measurements, precise construction details and coordination with electrical, water and air conditioning installations. Documentation is the guarantee that the project can be executed. 

Knowing the regulations: safety , accessibility, energy efficiency and fire protection. An interior designer does not improvise with regulations; he integrates them from the first line because they are part of the project, not a bureaucratic obstacle. Regulations protect people and improve spaces. 

The soft skills that make the difference 

Beyond pure technique, an interior designer needs other equally important skills that often make the difference between a good professional and an exceptional one:  listening and understanding: 

Listening and understanding. Every project is born out of a deep conversation. You have to ask the right questions, detect the real needs (which sometimes do not coincide with what the client says at the beginning) and genuinely empathise with how people live. Active listening is the first project tool. 

Communicate clearly and explain complex ideas in a simple way. To a client with no technical knowledge, to a supplier with his own language, to a builder in a hurry. If you don't know how to communicate your project, you don't know how to design. Visual and verbal communication is power. 

Manage time and money.Real projects have tight deadlines and limited budgets. You have to know how to prioritise without losing quality, adjust when things change on the fly and maintain the balance between the ideal and the possible. Management is applied design. 

Coordinating teams: An interior designer orchestrates many people: electricians, plumbers, carpenters, painters, furniture suppliers, lighting technicians. If you don't coordinate well, the project falls apart. Discreet leadership keeps everything on track. 

A real-life example from start to finish 

A client comes to you with a 70 square metre flat in the centre of Madrid. The problem: it's dark, has small unused rooms and the living room feels like a narrow corridor. The client works from home two days a week and needs a corner to concentrate, but without losing the living room as a living space. 

You start by measuring everything precisely. You detect that there is a non-load-bearing partition wall that is stealing light from the living room. You come up with a clear concept: "open up without losing privacy". You remove that partition, create a continuous space between the kitchen and the living room with a wooden lattice that filters the view without completely isolating, integrate a work area next to the window with storage under the seat and unify the floor with a continuous technical wood floor that visually enlarges the space.

You design three layers of light: a general one with recessed downlights, a specific one above the work table and an ambient one with LED strips hidden in the lattice. You choose warm and durable materials: oak for the floor, microcement in the kitchen, matt paint on the walls. You produce the technical plans, coordinate with the electrician and the carpenter, control the work and deliver the finished space. The client gains light, usable space and quality of life. That is interior design. 

Where does an interior designer work? Areas and professional opportunities

The good news is that interior design has professional opportunities in many different sectors. You are not limited to making houses. You can specialise in retail, hotels, offices, cultural spaces or events. Each field has its own rules of the game, but they all need someone who thinks about space with professional criteria. 

Housing: the closest and most familiar sector. You design houses, flats, complete renovations or partial interventions. You help people to live better in their daily lives, solving everything from the distribution to the last detail of lighting. 

Retail and shops: Here space is pure narrative. You design the customer journey, the strategic display points and the brand atmosphere. A good shop sells more because it works better, because it invites people to stay and because it tells a coherent story. 

Hotels and restaurants: The hospitality sector demands a balance between technical durability, economic maintenance and memorable sensory experience. Materials have to stand up to intensive use, but they also have to excite. This is the sector where the difference between good and bad design is most noticeable. 

Offices: Companies have understood that a well-designed space improves employee well-being and team productivity. They design individual concentration zones, formal meeting rooms, informal collaboration spaces and rest areas. Hybrid working has changed the rules of office design. 

Cultural and ephemeral spaces: museums , exhibitions, trade fair stands, temporary events. Here, immediate impact, technical modularity and rapid assembly are important. These are intense, visible projects with immovable deadlines. 

Lighting design: Some interior designers specialise exclusively in lighting. It is a technical, creative and highly demanded field that requires specific knowledge of photometry, colour temperature and lighting control. If you  discover that lighting is your passion on the Degree in Interior Design at UDIT, you can focus your career on this specialisation right from the start. 

 Specific professional profiles

Within interior design there are several professional profiles depending on your focus and specialisation: 

• Interior designer: the generalist profile that projects the entire space and coordinates the whole process from start to finish. 
• FF&E specialist: specialises in furniture, lighting and textiles. He or she selects and specifies each individual piece of the project. 
• Lighting designer: expert in integral lighting design. He masters the technique, emotion and regulations of architectural lighting. 
• Visual merchandiser: works in retail, designing the spatial narrative of shops and points of sale. 
• Project manager: manages large projects by coordinating internal teams, external suppliers and controlling quality and deadlines. 
• Render artist: produces 3D visualisations of projects, from the first sketches to the final photorealistic images. 

Interior design, decoration and home staging: they are not the same thing .

It is important to clarify this because many people confuse the terms. Being an interior designer is not the same as being a decorator, and neither does home staging. Each has its own specific function and its own competences. 

Interior design projects the entire space from the structure. They modify layouts, change installations, choose building materials and direct the work. It delivers complete technical plans and descriptive memory of the project. It is architectural intervention. 

Decoration works on a space that has already been built. It chooses furniture, textiles, colours, art and decorative objects. It does not touch the architecture or fixed installations. It is an aesthetic composition on an already resolved base. 

Home staging prepares a property to sell or rent it faster and better. It depersonalises the space, visually arranges it, improves the light and neutralises the aesthetics to attract the greatest number of buyers. It is a temporary, low-cost intervention with a clear commercial objective. 

All three are valid and necessary, but they do different things. If you want to change the layout of your house, you need an interior designer. If you just want to renovate the decoration without building work, you need a decorator. If you want to sell your flat quickly, you need home staging. Knowing these differences is essential if you are thinking of training professionally. 

Tools and software used by an interior designer 

Interior design relies on powerful digital tools. It is not enough to have a good eye; you have to know how to communicate your ideas with absolute technical precision. Software is the language in which projects speak. 

For 2D drawing: AutoCAD has been the industry standard for decades. It allows you to produce technical drawings with exact measurements, organised layers of information and professional documentation ready for construction. 

For 3D modelling: SketchUp and Rhino are the most widely used for creating fast volumes and exploring spatial options. Blender and 3ds Max are for more complex and detailed models. 

For visualisation: V-Ray and Enscape generate photorealistic renders that help the client see the project before building it. They are decision tools, not just presentation tools. 

To present: Photoshop , Illustrator and InDesign are used for concept boards, briefs and professional presentation documents. 

The important thing is not the tool itself, but the criteria behind it. Software helps you to think better, to explore more options and to explain clearly. But without a good idea behind it, the best rendering in the world is useless. Technology amplifies talent, it does not replace it. 

How to learn interior design: professional training

If you've come this far, it's because something has really hooked you. Maybe you imagine yourself designing spaces, choosing materials, drawing plans or coordinating construction work. The question now is: how do you really learn this? How do you go from curiosity to profession? 

A good interior design education should teach you how to design from day one, not just in the last year of your degree. It should combine solid theory and intensive practice, work with real projects that you might encounter in a studio tomorrow, use the professional software that the industry uses, and build a solid portfolio that opens real doors for you. It should also connect you with companies in the sector for internships and first job opportunities. 

In UDIT's Bachelor's Degree in Interior Design you'll find a curriculum that covers all of this in an integrated way: from technical drawing to construction management, from architectural lighting to complex project management, from sustainability to applied technology. You learn by doing, with teachers who are actively working in the sector and with projects that prepare you for professional reality from the very first year. 

The difference between a mediocre training and an excellent training lies in three things: how much you project from the beginning, who you learn with and what portfolio you build at the end. The rest is filler. A good degree allows you to enter the job market with confidence, with judgement and with projects that show you know how to do what you say you know how to do. 

The future of interior design: career trends for 2025 

Interior design is constantly evolving. What worked five years ago is obsolete today. Some current trends that define the professional sector: 

Real sustainability, not cosmetics.Clients demand materials with low environmental impact, full life-cycle analysis and responsible maintenance. This is no longer a trend; it is a market demand. 

Hybrid and flexible spaces: homes with integrated work corners and offices with domestic areas. The boundaries between home and work are blurring and design must respond to this reality without losing functionality. 

Invisible technology:simple home automation , useful sensors and tidy wiring that does not complicate everyday life. Technology should be invisible when it works well. Customers don't want complexity, they want comfort. 

Universal inclusive design:clear access , legible signage and design decisions that include all people without exception. Accessibility is no longer optional; it is spatial quality that the market values. 

Health and well-being: glare control, colour temperatures according to use, indoor air quality, integrated biophilia. Space directly affects the physical and emotional well-being of those who inhabit it. 

Your first step starts here 

Interior design is a profession for people who are curious, resolute and have a critical eye on the world. If you look at the spaces you live in, if you wonder why some work and others don't, if you imagine yourself improving places and making people live better, this could be the career path for you. 

You don't need to know how to draw like a pro from the start. You don't need to be an advanced mathematical genius. What you do need is genuine curiosity, a willingness to learn and an ability to observe. The rest can be trained, practised and perfected over time and with real projects. 

Start by looking at the spaces around you with fresh eyes. Ask yourself how your house is laid out, where the light comes in, what you like and what you would change. Analyse the cafeterias where you study, the shops where you shop, the offices where you work. This critical look is the starting point for every interior designer. When you want to turn that look into real projects, into professional technical plans and built spaces that improve lives, here you have the UDIT Degree in Interior Design waiting for you with a complete training plan that takes you from theory to practice from day one. 

Interior design is not just a profession. It is a way of looking at the world, of understanding how we live and of improving the spaces we inhabit every day. It is about solving real problems with creativity and technique. It is about transforming people's lives through space. And it all starts with a first step: deciding that you really want to learn and train with professional rigour. 

 Frequently asked questions

What do you need to study interior design? 

You don't need any specific prior knowledge to study interior design. What really matters is a curiosity for spaces, an ability to observe and a desire to learn. It helps to be able to express ideas visually, but it is not necessary to know how to draw at a professional level from the beginning. In UDIT's Bachelor's Degree in Interior Design,technical drawing, spatial representation and 3D modelling are taught from scratch. As for mathematics, the level required is applied: scales, measurements, surfaces and basic notions for budgets and installations. No purely advanced mathematics. 

How long does a degree in interior design take and what is the official qualification? 

The Bachelor's Degree in Interior Design lasts four academic years (240 ECTS credits) and awards an official university degree. This degree qualifies you to work as a professional interior designer in any country in the European Union and gives you access to official master's degrees. The training combines theory, intensive practice with real projects from the first year, professional internships in companies in the sector and the preparation of a final project. Unlike unofficial courses, a university degree guarantees a complete, recognised and internationally recognised academic training. 

What are the job opportunities for interior design in Spain? 

The job opportunities for interior design in Spain are wide and varied. You can work in interior design and architecture studios, in the design departments of retail chains, in hospitality companies (hotels and restaurants), in workplace consultancies (office design), in event and trade fair stand companies, in museography, in public administration or as a freelance professional with your own studio. There is also growing demand in sectors such as specialised lighting design, sustainability consultancy applied to interior spaces and the design of temporary commercial spaces. The Spanish market increasingly values official university training over non-regulated courses. 

What is the difference between studying interior design and architecture? 

Although both disciplines work with spaces, they have different approaches. Architecture focuses on the design of complete buildings, structures, facades and urban planning. Interior design specialises in interior space: layout, materials, lighting, furniture, acoustics and atmosphere. An interior designer delves much deeper into aspects such as sensory comfort, the psychology of space, specific lighting design and user experience. In the Interior Design Degree at UDIT you specialise from day one in interior design with all its technical and creative complexity, while in architecture interior design is only a small part of the programme. 

How much does an interior designer earn in Spain? 

The salary of an interior designer in Spain varies according to experience, specialisation and type of company. A newly graduated junior interior designer can start with salaries between 18,000 and 24,000 euros per year in small to medium-sized studios. With three to five years of experience, the average salary is between 24,000 and 35,000 euros per year. Senior profiles with more than ten years of experience, advanced technical specialisation or team management can exceed 40,000-50,000 euros per year. Freelance interior designers with their own studio have very variable incomes depending on their client portfolio and the type of projects. The best paid sectors tend to be hospitality, luxury retail, corporate offices and specialised lighting design. A formal university education and a good portfolio of real projects significantly improve entry opportunities and salary ranges. 

Do I need to be able to draw by hand to be an interior designer? 

It is not essential to have a high level of hand drawing from the outset, but it is a skill that is developed during training. Freehand drawing allows you to communicate ideas quickly in client meetings, make exploratory sketches and develop your spatial visualisation skills. However, most professional work is done with digital software: AutoCAD for technical drawings, SketchUp or Rhino for 3D modelling and rendering programs for visualisations. During the degree you are taught both manual technical drawing and professional digital tools, balancing both skills so that you are resourceful in any situation.