Interior Architect vs. Interior Designer in Seattle: What’s the Difference?

Homeowners planning a significant renovation in Seattle frequently encounter two titles: interior architect and interior designer. These roles overlap but are fundamentally different in training, licensing, and the scope of work they can legally perform. Understanding the difference helps you hire the right professional for your project.

What Is an Interior Architect?

An interior architect is a licensed architect who specializes in interior space — the design and transformation of interior environments. They hold an architecture license, which requires a professional degree (B.Arch or M.Arch), a multi-year internship under a licensed architect, and passage of the Architect Registration Examination (ARE). A licensed architect can:

• Stamp and seal construction drawings for building permit applications
• Design structural changes (wall removal, opening enlargement)
• Design mechanical, electrical, and plumbing system relocations
• Certify code compliance
• Practice architecture in any building type or occupancy

In Washington State, the title “architect” is protected by law. Only licensed architects can use it. An interior architect is an architect who practices primarily in interior environments.

What Is an Interior Designer?

An interior designer specializes in the aesthetic and functional design of interior spaces. In Washington State, interior designers are not required to be licensed, though the American Society of Interior Designers (ASID) and NCIDQ certification provide professional credentialing. Interior designers can:

• Select finishes, furnishings, fixtures, and fabrics
• Develop furniture plans and space layouts
• Specify lighting (decorative)
• Coordinate with architects and contractors on interior specifications
• Create interior design drawings (non-permitted scope)

What interior designers cannot do in Washington State: stamp permit drawings, certify structural or life safety code compliance, or perform architectural services that require a license.

When You Need an Interior Architect

Any renovation project that requires a building permit needs an architect’s drawings and stamp. In Seattle, this includes:

• Removing or modifying load-bearing walls
• Any structural change to the building
• Adding or moving plumbing fixtures (requires architectural drawings as part of the plumbing permit)
• Changing occupancy classification
• Any addition to the building footprint
• Commercial tenant improvements (always require permits)

If your renovation is entirely cosmetic — paint, flooring, light fixtures, furniture — you do not need an architect. If it involves structural changes or permits, you do.

When an Interior Designer Is the Right Hire

For projects that are entirely within the aesthetic and furnishing domain, an interior designer provides exactly the right expertise — and at a lower cost than an architect. Kitchen and bath selections, furniture procurement, color palettes, window treatments, art curation, and FF&E specification are all squarely within an interior designer’s practice.

Many significant renovation projects use both: an architect to produce the permitted drawings and design the spatial changes, and an interior designer to specify the finishes, furnishings, and fixtures that fill the space the architect created.

Interior Architecture at Piper Cole Architects

Piper Cole Architects’ interior architecture practice spans the full range of residential interior projects: whole-floor renovations, kitchen and bath redesigns, historic home interior updates, and the interior architecture of new custom homes. We produce permitted construction documents for all projects that require them and provide design services for projects that do not.

Our interior work is integrated with our residential and renovation practice — we design the building and its interiors as a unified whole, not as separate design exercises.

Related reading: What is FF&E? | Architect vs. design-build in Seattle