You are here:

Who comes first: Architect or builder?

Who comes first: Architect or builder?

If you are planning a home extension it can be tricky to know where to start. Do you call an architect first or a builder?

 Before you decide – ask yourself one simple question: “Do you know what you want?”

 Often many homeowners will have a clear idea of what style of extension they want to do. They may have seen a loft conversion or kitchen extension in a neighbour’s home that is similar to what they want to do. If you have a clear idea of what you want, it helps to make the build more straight forward. Many experienced builders will offer specialist one-stop shops for ‘standard-style’ extensions and take care of all the planning, drawing and building regulations.

 If you want something more bespoke or you are not quite sure how an extension would look, then an architect is often the best person to give you ideas. Traditionally, an architect will project manage all aspects of a home extension, choose the best builders and work with the local authorities to design, build and manage the project.

Which comes first - Architect or builder?

 Sam Dedarally, senior planner at Divi Designs says: “Nine out of 10 times, a project starts with a vision. If you’re not sure what you want, an architect can help you decide what is possible and take into consideration your needs, precedent of design and complexity to develop all the options.”

There is no law saying you must use an architect. Before deciding if and who to call first, there are three things homeowners should take into consideration:

  1. Budget
  2. Time-scale
  3. Personality


Using an architect will incur an extra fee, often 15-20 per cent more of the cost of a project. Currently, a first-floor extension can cost anywhere between £1200 and £2000 per m2 and then you have to factor in the architect’s fee on top of that. However, a good architect can also save you money on big projects. They are trained to see the big picture and focus on the small details, which can end up being costly mistakes if corners are cut.


How quickly do you want your extension built? If you are on a tight deadline, it may be quicker to go with a builder who will have experience in similar projects. While architects, depending on the complexity and context of your design, will consider all design aspects of the build – designing for natural light, flow and researching materials - which may take longer. 


No matter who you pick, you are going to be working with them, intently, for a substantial period of time. There has to be trust and a clear understanding of what you expect from each other to avoid any fall out. Builders might be in a rush to get started on their next job, architects might pressure you into doing things you don’t want to do. If you’ve done extension work before you might want to project manage some of the work or all of it yourself. Whether a builder or architect, make sure you are both on the same page for a stress-free extension.