3D Interior Design Renderings: What They Are, What They're For and Why They Change Everything Before a Renovation
By Mattea, co-founder and Interior Architect — Restylit
What is a 3D rendering for in interior design? A 3D rendering shows you exactly how a space will look — with the actual materials, precise proportions and planned lighting — before any work begins. It lets you spot mistakes when correcting them costs nothing, not when fixing them costs thousands. It's the tool that separates a guided renovation from a "fingers crossed" one.
The Problem That Renderings Solve
Imagine choosing bathroom tiles from a 10×10cm sample under fluorescent lighting in a showroom. You order them. You lay them. And only then do you realise that in your bathroom's natural light they look completely different from what you had in mind.
Or imagine choosing a wood-effect porcelain floor for the living room. Beautiful in the sample. Laid across 30sqm, with your grey sofa and white walls, it looks cold and clinical.
These aren't rare cases. They're the norm for anyone making decisions without a complete picture of the result.
A 3D rendering solves this problem at the source. It doesn't ask you to imagine how things will look — it shows you.
What Exactly Is a 3D Interior Rendering
A 3D rendering is a photorealistic, computer-generated three-dimensional image that shows a space as it will actually appear once completed.
It's not a sketch. It's not a floor plan. It's not a Pinterest mood board.
It's your room — your actual room, with your dimensions, the materials you've chosen, the furniture you'll buy, and the light that will come through that window at that time of day — reproduced digitally before a single brick has been laid.
A good 3D interior rendering includes:
- Exact proportions — based on the real floor plan of the space
- Real materials — the textures of that specific flooring, those specific tiles, that specific finish
- Real furniture — the actual 3D models of the products you'll purchase, not generic placeholders
- Simulated lighting — how natural light enters the space and how it interacts with the chosen colours
- Multiple viewpoints — from the entrance, from the sofa corner, from the kitchen looking into the living room
Why a 3D Rendering Is Worth the Cost: The Numbers
Let's do a concrete comparison.
Without a rendering:
- You choose bathroom tiles from a sample → you lay them → they don't work → redoing a bathroom from scratch costs €5,000–10,000
- You choose flooring for the living room → you lay it → it clashes with the furniture → it can't easily be changed
- You choose wall colours → you paint → the light in the room makes them look wrong → repainting: €400–700
- You buy the sofa → it's out of scale with the space → you return it or sell it at a loss: €300–700
Total potential avoidable mistakes: €1,500–15,000+ depending on the scope of the renovation.
With a rendering:
- You see tiles, flooring, colours and sofa in your actual room before purchasing → you adjust in the rendering → zero physical mistakes
- Cost of a rendering for an 80sqm apartment with Restylit Basic+3D: approximately €490
The arithmetic is clear.
What You See in a Rendering — and What You Can Change Before Starting
The value of a rendering isn't just aesthetic — it's decisional. Every element you see in the rendering is a choice you can adjust digitally before it's built physically.
You can change:
- Wall colours → without buying a tin of paint
- The type of flooring → without ordering a single square metre
- The position of the furniture → without moving anything physically
- The type of lighting → without drilling a ceiling
- Bathroom finishes → without laying a single tile
- Kitchen layout → without calling the builder
What you can't change in the rendering:
- Structural constraints — where the columns are, where the waste pipes run
- The actual natural light — the rendering simulates standard conditions; reality varies with season and weather
- Personal taste — the rendering shows what you've chosen, not what you should choose
The Process: How We Get to the Rendering at Restylit
At Restylit, the process that leads to the rendering works like this.
1. The client sends the materials Floor plan (even a hand-drawn photo works), current photos of the space, visual inspiration. Nothing complicated — no technical knowledge required.
2. The architect studies the space Analyses the proportions, sources of natural light, and existing constraints. Develops the layout proposal — where the furniture goes, how the space flows, how every corner is optimised.
3. Materials and furniture are selected The architect selects flooring, finishes, wall colours, specific furniture pieces, and lighting. Every choice is integrated into both the rendering and the shopping list.
4. The rendering is built The room is modelled in 3D with all the chosen elements. Lighting is set up, images are rendered. The result is what the client will see in the video call.
5. Presentation video call The client sees the rendering for the first time. They can ask questions, request adjustments, and approve the choices. This is the most important phase — where the project is validated or refined before a single euro is spent on materials.
6. Delivery Approved renderings, shopping list with direct product links, lighting layout, complete PDF. Everything ready to proceed with purchasing and works.
3D Rendering vs 2D Floor Plan: The Difference That Matters
Many studios produce 2D floor plans — a top-down view of the space with the furniture positioned. They're useful for the contractor but they don't show how the room will look.
The problem with a 2D floor plan is that it asks the client to "imagine" the three-dimensional result. And almost nobody can do that accurately. Proportions, heights, the relationship between volumes, colours, light — none of this comes through in a plan.
| 2D Floor Plan | 3D Rendering | |
|---|---|---|
| Shows the layout | ✓ | ✓ |
| Shows the colours | ✗ | ✓ |
| Shows the materials | ✗ | ✓ |
| Shows visual proportions | Partially | ✓ |
| Shows the lighting | ✗ | ✓ |
| Useful for the contractor | ✓ | Partially |
| Useful for the client | Limited | Enormously |
The floor plan is for the builder. The rendering is for you.
The Cases Where a Rendering Makes the Biggest Difference
Bathroom renovation The bathroom is the space where material choices have the strongest visual impact — and are the most expensive to get wrong. Tiles, finishes, sanitaryware, taps, lighting — everything needs to work together. The rendering shows whether it does before a single grout line is laid.
Open-plan kitchen and living room Two zones that need to communicate aesthetically while maintaining their own functional identity. Without a rendering, it's very hard to tell whether the boundary between the two areas is well managed or whether it will feel chaotic.
Bedroom with walk-in wardrobe The wardrobe significantly changes the proportions of the bedroom. The rendering shows whether the room still "breathes" after it's added — or whether it becomes a corridor.
Small apartments (under 60sqm) In a small space, every proportional mistake is amplified. The rendering lets you optimise every centimetre before it's committed.
Buying or renovating a new property You're working on a home you don't know well yet — perhaps in another city. The rendering gives you the complete picture you can't build without visiting it multiple times.
Photorealistic Renderings vs Conceptual Renderings: Not the Same Thing
Not all renderings are equal. There are two main levels.
Conceptual renderings Images generated quickly with simplified software. They give a general idea of the space — furniture positions, colour palettes — but they're not photorealistic. Materials look plastic, lighting isn't simulated correctly, and furniture pieces are generic.
Photorealistic renderings Produced with professional software. Light interacts with materials in a physically accurate way. Textures are high-resolution. Furniture pieces are the actual 3D models of the products that will be purchased. The final image is difficult to distinguish from a professional photograph.
At Restylit we produce photorealistic renderings — not conceptual ones. The difference is that what you see in the video call is genuinely what you'll build. Not an approximation — an accurate forecast.
Before and After: Real Restylit Projects
On the Restylit website, every case study shows two images side by side: the 3D rendering produced before the works, and the photo of the completed space.
The comparison is consistently very close — not because we photograph well, but because the rendering is accurate. That's the internal benchmark we use: the rendering must predict the real result with the highest possible fidelity.
If the client sees the rendering and then sees the finished room and recognises it, we've done our job well.
How Much Does a 3D Rendering Cost at Restylit
The 3D rendering is included in these packages:
Basic + 3D — from €249 (price based on sqm) Photorealistic rendering, moodboard, shopping list, lighting concept, 45-minute video call. The most popular format for those furnishing from scratch or refreshing an existing space.
PLUS — from €499 (price based on sqm) Everything in Basic+3D, plus one executive technical drawing. For those who need the rendering and a document to hand over to the contractor.
Essential — €33/sqm (min. 100sqm) Rendering with 2 revision rounds, multiple video calls and up to 4 technical drawings. For complete renovations.
Advanced — €55/sqm (min. 100sqm) Rendering with 3 revision rounds, up to 8 technical drawings, cost estimate. The most comprehensive service.
For an 80sqm apartment on the Basic+3D package, the rendering costs approximately €490 — 6% of an €8,000 furniture budget. Real coverage against the most costly mistakes.
FAQ
Does the rendering include the exact products I'll purchase? Yes — the shopping list is built in parallel with the rendering, with direct links to the specific products. What you see in the rendering is what you can buy. If a product is discontinued between delivery and purchase, we suggest equivalent alternatives.
Can I request changes after the first rendering? For Basic+3D and PLUS packages, significant changes after the presentation video call are generally billed separately. Essential and Advanced packages include 2 and 3 revision cycles respectively within the process.
Does it work for bathrooms and kitchens too? Yes — and these are often the cases where the rendering delivers the most value, because material choices in these rooms are the most expensive to get wrong and the hardest to correct.
How accurate is the rendering compared to the real result? With a precise floor plan and clear photos, accuracy is very high for proportions, colours and materials. The main variable is natural light — which changes with the time of day, season and weather conditions. The rendering shows light in standard conditions; reality varies around that baseline.
Can I show the rendering to the contractor? Yes, and it's highly recommended. Renderings communicate the expected result far more effectively than any verbal description. Many contractors appreciate having a rendering as a reference — it reduces misunderstandings and change requests during the works.
How long does it take to receive the renderings? For Basic+3D and PLUS packages: approximately 30 days from when the materials are received. For Essential and Advanced: included within the total 60–70 day project timeline.
Start With the Rendering
If you're renovating or furnishing and aren't sure where to begin, the rendering is the right starting point. Not because it's mandatory — but because it's the most economical way to have certainty before you spend.
For a €10,000 renovation, a rendering that costs €490 is 5% of the total budget. Real protection against the most expensive mistakes.
Discover packages with 3D renderings →
Restylit is an Italian interior design company, entirely online. We design residential and commercial spaces with photorealistic 3D renderings, shoppable furniture lists and technical drawings for the contractor — across Italy and Europe.


