What Does an Interior Designer Do? A Client's Guide

An interior designer plans how a space works and looks, then documents it so builders can make it real. In practice that means measuring the space, drawing layouts, choosing materials and products, producing visualizations, preparing construction drawings and a specification, and checking during the build that the result matches the plan. A decorator styles a room. A designer can move walls.

That's the definition. Below is what the job looks like from the client's side, stage by stage, and which parts you're really paying for.

Designer, decorator, architect: who does what

For an apartment renovation, the interior designer is usually the right person. For a new house, you need both. At our studio the two are one team.

What the designer actually does, stage by stage

Listens, then asks awkward questions

The first conversation is about your life, not your taste. Who cooks. Who works from home. Where the bikes go. What drives you mad in your current home. A good brief saves more money than any material choice.

Measures

Exact dimensions of every wall, opening, riser and ceiling. Everything later depends on them. It can be done on site, from the developer's as-built drawings, or by a local surveyor if the designer works remotely.

Plans the layout

This is the most valuable part of the job and the least photogenic. Where walls go, where the kitchen sits, how storage fits, how you move through the space. We give two or three options and revise until one works, up to three rounds.

Shows you the result before it exists

Visualizations of every room, with the actual materials. You approve a picture, not a description. That removes most "I imagined it differently" moments.

Writes the instructions for builders

Construction drawings: demolition and new walls, electrics, plumbing, ceilings, floors, tile layouts, joinery elevations. Plus a specification: every product with manufacturer, part number and quantity. This album is what your crew builds from. Without it, the crew decides.

Checks the build

During construction the designer answers the builders' questions and compares each stage with the drawings, on site or through photo and video reviews. Catching a wrong socket before plastering costs nothing. After, it costs a wall.

What an interior designer doesn't do

• Build. Unless the studio also offers construction management, the builders are a separate contract.
• Guarantee a budget they don't control. A designer can design to a budget and specify products at known prices. The final cost depends on the builders' quote and your choices.
• Replace your decisions. You approve every stage.

How long it takes and what it costs

For an apartment of about 100 m², a full project takes 4–8 weeks. Prices vary widely by country and studio. Ours are published: €35/m² for layouts and visualizations of every room, €50/m² with drawings and specification, €80/m² with two months of support on site. More detail in how much an interior designer costs.

Do you need one?

For a cosmetic refresh, probably not. For a renovation where walls, the kitchen or bathrooms move, usually yes — the project typically costs 8–12% of the renovation budget and prevents the redoing that often adds 20–30%. We wrote a separate, honest comparison: can you design your own apartment.

Frequently asked

Does an interior designer need to visit the property? Not necessarily. We've completed 1,172 projects in 48 countries, mostly remotely.

Does the designer buy furniture for me? Some do, as a separate service. The specification lets you or anyone else buy the exact items.

Can I use my own builders? Yes. The drawings are made for any competent crew.