Architect vs. Builder vs. Interior Designer – Who Does What?

Bright and welcoming entrance hallway featuring a modern oak staircase, glass balustrade, and warm timber finishes — reflecting the architectural role in setting spatial tone and flow from the outset of a home design project.

Starting a building or renovation project is exciting—but it can also feel overwhelming when you're not sure who does what. Should you hire an architect, a builder, or an interior designer first? Do you need all three?

At Karenna Wilford Architects, we often guide clients through this very question. Each role brings unique expertise to a project, and understanding the differences early can help you plan smarter, avoid missteps, and build with confidence.

The Role of an Architect

Architect presenting a set of plans to a couple in a modern home studio — illustrating the design and planning stage of a project.

Architects are the conceptual and technical masterminds behind a project. Their role is to take your ideas and shape them into a well-thought-out design that is:

• Functional and beautiful

• Structurally sound

• Aligned with planning policies and building regulations

• Responsive to light, views, and the context of the site

  
  

Architects think big-picture: how spaces connect, how a home flows, and how to elevate your daily rituals through thoughtful design.

They also handle or coordinate:

• Planning applications

• Technical drawings

• Consultant teams (structural engineers, surveyors, etc.)

• Tendering and contract administration

The Role of a Builder (Contractor)

Builders on-site.

Builders, or contractors, bring the architect’s plans to life. They are responsible for:

• Costing and pricing the build

• Hiring and managing subcontractors (electricians, plumbers, roofers)

• Carrying out construction work

• Following the specifications and drawings provided by the architect

  
  

While some experienced builders may offer design input, their strength lies in construction. They’ll flag potential practical issues and ensure your home is built to code.

The Role of an Interior Designer

Interior designer arranging floor samples on a table in a well-lit home office — reflecting the aesthetic and material planning phase.

Interior designers work inside the finished shell of your home. While some are involved early in layout planning (especially for kitchens, bathrooms, or bespoke joinery), their core focus is on:

• Material and colour palettes

• Furniture layouts

• Lighting and fixtures

• Textiles and styling

• Creating mood and personality within the space

  
  

A good interior designer brings cohesion, comfort and detail to the finished home. Many collaborate closely with architects to ensure design harmony.

How These Roles Work Together

The best projects happen when architects, builders, and interior designers collaborate from the outset.

An architect sets the vision and structure, the builder realises it, and the interior designer refines the human experience within. When they communicate well, there are fewer site surprises, smoother timelines, and a more cohesive outcome.

If you’re unsure where to begin, start with an architect. We can help:

• Clarify your brief

• Connect you with trusted professionals

• Oversee the entire process from concept to completion

  
  

Summary Table

Role	Focus	When to Involve
Architect	Spatial design, structure, regulations	At the start of the project
Builder	Construction and cost management	After design is confirmed
Interior Designer	Materials, furniture, lighting	During or after construction

Ready to Begin?

Whether you’re building from the ground up or rethinking a single room, understanding who does what can save you time, money and stress.

If you're not sure where to start, Karenna Wilford Architects can help you develop a clear plan, assemble the right team, and design a home that works beautifully—inside and out. Contact Us Today.