Short answer: a contractor builds what you specify, while an interior designer (ID) works out what to build and usually manages the whole project. For small, clearly defined jobs, a contractor is enough. For a full renovation where layout, storage and finishes all need deciding, an ID or a design-first approach saves time and mistakes.

What a contractor does

A renovation contractor carries out the works: hacking, masonry, tiling, carpentry, electrical, plumbing and painting, either with their own team or by coordinating subcontractors. Some act as a "main contractor" so you deal with one person.

What a contractor usually does not do is design. If you hand over a clear brief, such as "vinyl in all rooms, two wardrobes to these measurements, repaint white", a good contractor will deliver it well. If the brief is vague, the contractor fills the gaps, and you may not like the result.

Choose a contractor when:

  • The scope is small or very clear (repainting, flooring, a kitchen refresh).
  • You are confident making design decisions and checking details on site.
  • You have the time to coordinate and inspect works yourself.

What an interior designer does

An interior designer starts with how you live, then produces a layout, a design direction, drawings and often 3D views. In Singapore, most ID firms are one-stop: they design, quote, and run the renovation through their own contractors.

Choose an interior designer when:

  • You are renovating several rooms and want them to work together.
  • You need help with layout, storage and lighting, not just finishes.
  • You would rather have one party responsible for the whole project.

How each one charges

Contractors price the works. IDs in Singapore usually build their design and management fee into the renovation package, rather than charging it as a separate line. That is convenient, but it makes it hard to see what the design itself costs, and it often means you only see detailed drawings after paying a deposit and committing to that firm.

The risks on each side

With a contractor only, the most common problems are gaps in the brief: missing power points, carpentry that does not fit the appliances, or a layout that looks fine on paper but feels cramped. These turn into variation orders and rework.

With an ID, the common issue is lock-in. Once you have paid a deposit, switching firms is costly even if you are unhappy with the design or the price.

Whichever you choose, check that anyone doing works in an HDB flat is listed in HDB's Directory of Renovation Contractors. HDB's renovation rules require it.

A third option: design first, then choose who builds

This is how JIAHOME works, and why we started. Our founders collected almost 20 quotations for their own first home and could not compare any of them, because every firm was pricing a different idea.

So we separate the two jobs:

  1. We design your home first: mood boards, 2D layouts and up to 10 3D views, for a fixed fee.
  2. You get a quotation with every item listed and no prices filled in. Any contractor or ID can price exactly the same scope.
  3. You choose who builds it: manage it yourself with our guidebook, hire our project manager, or take the design to the ID firm of your choice.

You see your home before you commit to a renovation contract, which is what we mean by design before deposit. Have a look at our services, or browse our design concepts to find your style.

Last updated 14 October 2026