You've decided to hire an interior designer. But how do you choose the right one? This isn't like hiring a tradesperson where you can quickly assess competence by asking for references. Interior design is subjective, long-term, and expensive. Choosing poorly will cost you thousands of pounds and years of frustration.
In 35 years of selecting designers for homeowners like you, we've developed a rigorous vetting process. This checklist helps you identify designers who will deliver excellence versus those who will disappoint.
The Credentials Tier: What Matters & What Doesn't
SBID (Society of British Interior Designers)
This is the gold standard. SBID membership requires formal design education, professional experience, and adherence to a strict code of conduct. If a designer is SBID registered, you can trust they've met rigorous standards.
What to check: Ask for their SBID membership number. Verify it on the SBID website.
BIID (British Institute of Interior Design)
BIID is similar to SBID — another respected body that vets designers. Less stringent than SBID but still a mark of professionalism.
No Credentials
This doesn't automatically mean a designer is unqualified. Many excellent designers never formally joined professional bodies. What matters is their track record, their process, and how they communicate.
Credentials Checklist
- Are they SBID or BIID registered? (Check the website.)
- How many years of professional design experience?
- Have they completed formal design education? (Degree, diploma, or equivalent.)
- Are they insured? (Professional indemnity insurance is essential.)
- Do they have a track record of completed projects in your sector? (Residential luxury, not commercial.)
The Portfolio Assessment: What to Actually Look For
A designer's portfolio should tell you everything about their aesthetic range, quality of execution, and project scope.
Range vs. Consistency
A designer who specialises in a specific aesthetic (Scandinavian minimalism, English countryside, contemporary luxury) is usually better than one who claims to do everything. Specialisation means expertise. Breadth often means inconsistency.
Look for three to five completed projects that closely match what you're trying to achieve. These should be before-and-after photos, not just styled images of the finished spaces.
Quality of Finish
Look at close-up details. Are the grout lines straight on tiles? Are paint finishes even? Do skirting boards meet walls cleanly? Are worktops flush with cabinetry? These are indicators of quality project management.
Evidence of Project Management
The best portfolios include case studies that explain the project scope, timeline, budget, and challenges overcome. Look for evidence that the designer managed multiple trades, solved problems, and delivered on time and budget.
Portfolio Checklist
- Do they have 3–5 completed projects similar to yours?
- Are there before-and-after photos, not just finished images?
- Do the finishing details look meticulous?
- Are there case studies explaining process, timeline, and budget?
- Do they have experience with your project type? (Kitchen, bathroom, full home, etc.)
- Are the photographs recent? (Within 2–3 years.)
- Can you contact previous clients for references?
The Fee Transparency Test
How a designer discusses fees tells you everything about how they manage client relationships.
Clear Fee Structures
Good designers explain exactly what they charge and what's included. This might be:
- Percentage of total project cost. Usually 10–20% depending on scope.
- Day rate. Typically £500–£1,500 per day depending on experience.
- Hourly rate. Usually £75–£200 per hour.
- Fixed project fee. For specific scopes like "kitchen design specification: £4,000".
The method matters less than clarity. You should know exactly what you're paying for.
What's Included vs. What's Extra
A good designer will provide a detailed brief explaining:
- What's included in their design fee (drawings, specifications, site visits, etc.)
- What costs extra (design changes beyond a certain number, rush fees, overtime)
- Payment schedule (deposit, milestones, final payment)
- Refund or cancellation policy
If a designer is vague about fees, walk away.
Red Flag: Vague Pricing
A designer who says "I'll know once I see the space" or "We'll discuss fees after the consultation" is either disorganised or planning to upsell. Professional designers know their costs and can quote quickly.
Fee Transparency Checklist
- Do they provide a written fee proposal before starting work?
- Is the fee structure clear and documented?
- Do they explain what's included and what's extra?
- Is there a payment schedule with clear milestones?
- Do they provide an estimate for the overall project cost?
- Are additional costs (travel, samples, rush fees) explained upfront?
The Communication Style Assessment
You're committing to a 6–12 month relationship with this designer. Communication style matters enormously.
Responsiveness
Send them an email or make a call. How long do they take to respond? Good designers respond within 24 hours. If it takes a week, they're either overbooked or disorganised.
Listening vs. Telling
In your initial consultation, does the designer ask questions about your lifestyle, your priorities, and your aesthetic preferences? Or do they immediately start telling you what you need?
Good designers listen first, design second.
Clarity of Communication
Can they explain design decisions clearly? During your consultation, if they use jargon without explaining it, or if their explanations confuse rather than clarify, this is a warning sign. Design is about solving problems, not showing off expertise.
Willingness to Educate
A good designer educates clients about why certain choices matter — why bespoke cabinetry costs more, why certain materials age better, why specification choices affect the final result. This builds confidence in their guidance.
Communication Checklist
- Do they respond to queries within 24 hours?
- In the consultation, do they ask questions or do all the talking?
- Can they explain design decisions in plain language?
- Are they defensive about suggestions, or do they engage with feedback?
- Do they explain costs and project decisions clearly?
- Are they available for regular communication during the project?
The Project Management Capability Test
A designer with a beautiful portfolio but poor project management will deliver disappointment.
Experience with Your Project Scope
Have they completed projects similar in size and complexity to yours? A designer experienced in small residential refreshes might struggle with a £250,000 full-home renovation requiring structural work.
Trade Coordination Experience
Ask directly: "How do you manage multiple trades on site? What's your process for resolving problems if something goes wrong? How frequently do you visit site?" Their answers reveal maturity as a project manager.
Budget Management Track Record
Ask about their average project contingency usage. Professional designers typically use 5–8% of contingency. If they use more, they're bad at estimating. If they never use contingency, they might not be planning for reality.
Timeline Delivery
Have they delivered projects on schedule? Ask for a previous client you can contact about this specific question.
Red Flag: Lack of Project Management Process
If a designer can't clearly explain how they manage trades, communicate with clients, handle changes, or monitor budgets, they're not equipped for a complex project.
The Price Anchoring Exercise: Are Their Fees Competitive?
Interview three designers you're seriously considering. Ask each for a fee quote for your project scope. The ranges will teach you a lot.
If one designer quotes significantly below the others, be cautious. They might be undervaluing their work, which often means rushing or under-delivering. If one quotes significantly above, understand why — is it based on more experience, or premium positioning?
The middle range is usually the safest bet, assuming they meet all other criteria on this checklist.
The Reference Check: Non-Negotiable
Before committing, speak with at least two previous clients. Ask:
- "Did the designer deliver on time and budget?"
- "Were there unexpected costs? How were they handled?"
- "How did the designer respond when problems arose?"
- "Would you hire them again?"
- "What surprised you — for better or worse?"
Pay attention to how clients talk about the designer. Enthusiasm and genuine recommendation are good signs. Hesitation or qualifications ("they're good, but...") suggest deeper issues.
Reference Check Checklist
- Can they provide 2–3 recent client references?
- Did previous projects finish on time and budget?
- How did the designer handle unexpected issues?
- Would previous clients recommend them without hesitation?
- Can you speak with clients about projects similar to yours?
The Red Flags: When to Walk Away
Red Flag: Pressure to Decide
"I have another client interested" or "This timeline won't wait" are manipulation tactics. Good designers don't pressure. If you feel rushed, walk away.
Red Flag: Dismissiveness of Your Input
If a designer dismisses your priorities or aesthetic preferences as "wrong" or "outdated," you've found someone who designs for themselves, not for clients. Design is a collaboration.
Red Flag: Lack of Insurance or Contracts
Professional designers carry professional indemnity insurance and use written contracts. If they don't, you have no protection if something goes wrong.
Red Flag: Unwillingness to Discuss Budget
If a designer avoids discussing budget constraints or acts like budgets are beneath them, you'll have cost surprises. Good designers work within budget as a fundamental requirement.
Red Flag: No Clear Project Management Process
If they can't explain how they'll manage your project, coordinate trades, handle changes, or track budgets, they're not equipped for anything beyond basic styling.
The Final Gut Check
After you've worked through this checklist, ask yourself: Do I trust this person? Not "like" — trust. Will they advocate for my interests? Will they solve problems rather than create them? Would I recommend them to a friend?
Trust matters more than credentials. A certified designer you don't trust will disappoint you. A self-taught designer you trust will exceed expectations.
The best designers combine both: proven credentials, a track record of excellent projects, clear communication, robust project management, competitive fees, and — most importantly — genuine care about delivering what the client actually wants.