The practical test
Divide the proposed work into decoration, nonstructural planning and building coordination. None is automatically outside code review: finishes and layouts can affect fire safety and accessibility.
CIDQ’s professional definition includes space planning, code compliance and coordination within interior design. Legal permission is a separate question. The California Architects Board’s guide describes local exemptions for nonstructural interior alterations, alongside restrictions involving safety and licensed practice. Ask the relevant authority about your project.
Takeaway: Scope and local rules assign responsibility more reliably than a job title.
Match tasks to competence and collaborators
Swipe sideways to see the other columns. The first column stays visible.
| Work task | Ability / approval to verify | Collaboration to record |
|---|---|---|
| Decoration and loose furniture | Selection competence; applicable material and access requirements | Client / supplier / installer |
| Non-load-bearing space planning | Layout, escape and accessibility review; local submission rights | Interior designer / building authority; architect as scope requires |
| Walls, openings and levels | Establish structural status; check permit and professional requirements | Architect / structural engineer / contractor as required |
| Lighting and services | Design intent, service capacity and installation responsibilities | Designer / services engineer / qualified installer |
| Finishes and fixed joinery | Substrate, loading and applicable fire classification | Designer / relevant engineer / installer |
Takeaway: A finish decision can still need technical or regulatory checks.
Why the sequence matters
Fabric decisions constrain finish decisions, not the other way round. Deciding on a finish before knowing what wall it goes on is how projects end up with a material that the substrate cannot carry or that the fire requirement excludes.
The order that works:
- Fix the fabric — walls, openings, levels, services routes.
- Establish the constraints each surface imposes — substrate, movement, load, moisture, fire.
- Then select finishes within those constraints.
Reversing steps 2 and 3 is the most common source of late substitution. See interior wall finishes guide for what each finish family demands of its substrate.
Where the confusion causes real problems
Appointing on the wrong side of the line. A finishes appointment does not establish authority or insurance for wall removal. Before widening the scope, review the contract and actual insurance documents, and appoint the required specialist.
Assuming approval is not needed. Interior-only work still triggers approval requirements in many jurisdictions — changes to escape routes, fire compartmentation, structural openings, and sometimes change of use. This must be checked locally rather than assumed.
Choosing finishes from images before the fabric is fixed. The image shows a result that depended on ceiling height, window position and wall construction you may not have.
What to ask when appointing
Copy and fill this appointment record; keep the answers with the agreed scope.
| Question | Written answer / document reference |
|---|---|
| Which tasks are included or excluded? | ___ |
| Which local regulator and building authority apply? | ___ |
| What registration, submission rights or exemption applies? | ___ |
| Who coordinates structural and services decisions? | ___ |
| Who submits approvals and signs each deliverable? | ___ |
| Does the contract and insurance cover the assigned work? | Scope / policy / exclusions / date: ___ |
| When are finishes fixed, and who approves changes? | ___ |
Takeaway: Resolve responsibility before the scope expands. Compare feature-wall finishes, textures and interior versus exterior products.
Frequently asked questions
Do I need an architect for an interior-only project?
List the proposed alterations and ask the local building authority who may design and submit them. Requirements and exemptions depend on location and scope. Check the practitioner's registration where required, written appointment and insurance coverage for those tasks.
Is interior architecture a protected title?
Do not infer legal status from the title. Check the project jurisdiction's regulator for protected wording and practice limits. California Architects Board guidance, for example, distinguishes architect title restrictions from exemptions for specified nonstructural interior work; this is not a global rule.
Who decides lighting?
Both, at different stages. Where light fittings go, and what has to be wired and where, is fabric work. Which fitting, and what colour temperature and beam angle it has, is design work. The wiring decisions close first.
Can one person do both?
Frequently, and it often produces a more coherent result. What matters is that the fabric decisions are made by someone competent to make them, and that they are made before the finish decisions depend on them.
Sources
- RIBA Plan of Work — Royal Institute of British Architects (RIBA) Accessed August 27, 2026.
- Building Official Information Guide — title restrictions and exemptions — California Architects Board Accessed October 8, 2026.
- What Is Interior Design? — professional scope, not legal permission — Council for Interior Design Qualification Accessed October 8, 2026.