Journal / Designers
What does an interior designer do?
Words by the Bathroom Edit editor · Updated on 3 October 2026 · 2 min read
An interior designer plans how a room works as well as how it looks: layout, materials, lighting and the drawings a builder follows. A decorator styles the room you have. Here is the difference, step by step.
An interior designer works out how a space should function and look, then documents it: the layout, materials, fixtures and lighting, with drawings and a specification the builder and trades follow.
Designer, decorator, stylist
| Interior designer | Interior decorator | Stylist | |
|---|---|---|---|
| Changes the layout | Yes | No | No |
| Chooses tiles, fixtures, joinery | Yes | Sometimes finishes | No |
| Furniture, colour, soft furnishings | Yes | Yes | Yes, for a shoot or sale |
| Drawings for the builder | Yes | No | No |
| Works with trades on site | Often | Rarely | No |
The steps of a design project
- Brief. How you live, what is wrong with the room, the budget.
- Concept. A layout and a mood or spec board of materials.
- Design development. Fixtures, tiles, joinery and lighting chosen and priced.
- Documentation. Plans, elevations and a specification for quotes.
- On site. Answering trades' questions and checking the work.
Builtly describes the most common full-service model as a fixed design fee for these phases plus a mark-up on furniture and fittings bought through the designer.
What each costs
Kaiko Design Interiors notes decorators often work hourly or on room packages from around $1,500 to $5,000, while designers charge more because of the documentation and coordination. Full fees: how much an interior designer costs.
Common questions
What is the difference between an interior designer and a decorator?
A designer can change the layout and documents the work for a builder; a decorator works with the existing room's finishes, furniture and styling.
Do I need an interior designer for a bathroom?
Not always. For a full renovation with a new layout, a designer's plan and tile drawings help; for new fittings in the same layout, a good builder or an hourly consultation may be enough.