An interior designer is a professional who designs and specifies the interior spaces of buildings. The title is not protected in the UK - anyone can use it - so membership of a professional body such as the British Institute of Interior Design (BIID), the Chartered Society of Designers (CSD) or Interior Designers at RIBA (IDr) is the main quality indicator. Interior designers work across domestic renovations, new builds, commercial offices, retail and hospitality. Their scope typically covers space planning, layout optimisation, lighting design, materials and finishes specification, furniture specification and procurement, and coordination with contractors and suppliers. For projects involving structural changes, planning permission or Building Regulations, an interior designer would normally work alongside an architect or architectural technologist.
What they do
- Space planning and layout design for residential and commercial interiors
- Colour, material and finishes specification for walls, floors and ceilings
- Lighting design and specification - ambient, task and feature lighting
- Furniture specification, sourcing and procurement
- Kitchen, bathroom and joinery design and specification
- Soft furnishings, window treatments and accessory specification
- Contractor and supplier coordination and site visits
- Mood boards, 3D visuals and concept presentations
When you need one
An interior designer adds most value when you want a cohesive, professionally resolved interior - particularly on full renovations, new builds or commercial fit-outs where the investment is significant.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| Initial consultation (hourly) | £75 - £150 / hr |
| Full design service (residential room) | £1,500 - £5,000+ |
| Full home interior design service | £5,000 - £30,000+ |
| Kitchen design and specification | £2,000 - £8,000 |
| Commercial office fit-out design | £3,000 - £15,000+ |
| Procurement management fee (% of budget) | 10% - 20% |
Fee structures vary: some designers charge hourly, some a fixed project fee, and some earn a trade discount on specified products. Always agree the fee structure, what is and is not included, and how procurement is handled before appointing.
Qualifications to look for
BIID membership requires a minimum Level 5 qualification in interior design and a commitment to a code of conduct and continuing professional development. Verify membership at biid.org.uk. BIID members are required to hold PII.
Professional body covering all design disciplines. Chartered Designer (CDesRCA or FCSD) status is the highest grade and requires peer assessment. Membership provides a professional benchmark across interior and product design.
A specialist membership route within RIBA for interior designers who meet RIBA's quality and CPD requirements. Suitable for designers working closely with architects on more complex interior projects.
How to find a reputable interior designer
Frequently asked questions
Is interior designer a protected title in the UK?
No. 'Interior designer' is not a protected title in the UK - anyone can use it. When appointing an interior designer, check for membership of the British Institute of Interior Design (BIID), Chartered Society of Designers (CSD) or Interior Designers at RIBA (IDr). BIID membership in particular requires a qualifying qualification and adherence to a code of conduct, making it a reliable baseline for professional competence.
What is the difference between an interior designer and an interior decorator?
An interior designer covers the full scope of a project - space planning, layout, structural changes, lighting, specification and procurement. An interior decorator focuses primarily on surface finishes: paint colours, wallpapers, soft furnishings and accessories. Many practitioners use both titles interchangeably but the scope of work offered can differ significantly. Always clarify the services included before appointing.
Can an interior designer submit a planning application?
An interior designer can submit a planning application but is typically only qualified to do so for works within the interior of a building. For any external alterations - extensions, changes to the building envelope, external materials - you will need an architect or architectural technologist. Some interior designers work closely with architects and can project-manage the whole process, but building design and structural work falls outside their core scope.