Interior Design
Planning interior spaces, finishes, and furnishings so they work, look right, and stay safe.
Quick Answer
Interior design is the profession of planning and detailing the inside of buildings so they are functional, safe, and visually coherent. Interior designers handle space layouts, finishes, lighting, furniture, and code-related details. It goes beyond decoration by requiring technical knowledge of building codes, accessibility, and construction.
The Full Picture
Interior design covers the layout and look of the inside of a building. Designers study how people will use a space, then plan circulation, furniture and equipment, lighting, materials, colors, and finishes to support that use. In commercial work, the interior is often designed and built as its own project, such as a tenant improvement or fit-out.
It is distinct from interior decoration, which focuses on furnishings and surface styling. Interior designers also address technical matters: egress paths, fire ratings of finishes, accessibility, and coordination of partitions, ceilings, and lighting with the architectural and engineering systems. Many states regulate the title or practice, and the NCIDQ exam, administered by CIDQ, is a common qualification.
On a project, interior design work usually runs alongside architecture. The architect may include interior design in their own scope, or a separate interior design firm may be engaged. Their drawings include finish schedules, reflected ceiling plans, millwork details, and furniture plans, and the contractor builds from them or coordinates with owner-supplied furniture.
From a construction standpoint, interiors are often where budgets drift. Finish selections, custom millwork, and fixture upgrades can change cost late in design, so early coordination between designers, owners, and estimators keeps the budget and schedule realistic.
Real Examples
Common Misconceptions
People assume: Interior design is the same as decorating.
Actually: Decorating is about furnishings and styling. Interior design also involves space planning, building code and accessibility compliance, and technical documentation for construction.
People assume: Interior design only affects how a space looks.
Actually: Layout, lighting, acoustics, and material choices affect safety, productivity, and operating cost as well as appearance.
Frequently Asked Questions
What do interior designers do?
They plan layouts, select materials and finishes, specify lighting and furnishings, coordinate with architects and engineers, and produce drawings and schedules that guide construction.
Is interior design regulated?
It depends on the state. Some regulate the practice, others only the title, and some do not regulate it at all. The NCIDQ exam is a common credential.
What is a tenant improvement?
A tenant improvement, or TI, is a build-out of leased interior space to suit a tenant's needs. Interior designers commonly lead the design.
What drawings do interior designers produce?
Typical sets include floor and furniture plans, reflected ceiling plans, finish plans and schedules, elevations, and millwork or custom detail drawings.