What they do An interior designer will do some or all of the following:

• Provide design services, from drawing up a design to furnishings and the finishing touches;
• Act as a communicator between you and painters, suppliers, or decorators;
• Source furnishings, fittings and equipment;
• Oversee simple building works and decoration.

Design or decorate? The British Interior Design Association (BIDA) defines an interior designer as a person who is qualified to work on 'interior spaces including space planning, using specialised knowledge of interior construction, as well as decoration'. In comparison, an interior decorator can 'give advice on decorative styles and schemes, including accessories and furnishings, but will not enter into building contracts or construction'.

Finding a designer Ask for recommendations from family and friends; or find a room that you love and find out who designed it.

Quality assured  The BIDA website (www. bida.org) allows you to source registered BIDA interior designers who are checked to ensure they meet certain professional and legal requirements (all BIDA members have to have professional indemnity insurance – check that your designer has, too). Search by location or area of expertise.

Be prepared  Think about what you want from your space. Ask yourself the questions that a designer might ask, such as: What is this space used for? Who uses it? What is the budget and timescale? Decide what your style is and have a clear brief. Look at books, magazines and websites for inspiration.

Selection process  Interview several designers; ask to see their portfolio and references. Discuss the designer's qualifications, as well as your project deadline and the designer's availability. Don't be afraid to discuss their fee at this point. You'll need to trust and work closely with them, so choose someone you get on well with.

Cost vs value  Compare the designers' cost estimates, but don't base your decision on price alone. Check what is included, and the quality of service and products they can offer.

Ways to pay  Most interior designers will charge either:

• A fixed fee – applied to the complete service, from design planning to layouts and finishing touches;
• An hourly fee – based on the time the designer spends on the project;
• Percentage fee – the designer buys the materials, furnishings and services at cost price, then sells them to you with an agreed added percentage.

Get it in writing  Drawing up a contract will ensure you are both aware of who's responsible for what, and what the projected timescale and budget will be.

Talk it through  Discuss the project in depth with your chosen designer; share your ideas, and allow the designer to input their observations. Make adjustments until you're confident and happy with what they have in mind. Your designer should explain the entire process, helping you to visualise the end result through drawings, a written brief and cuttings, or mood boards.

Avoid surprises Late changes will increase costs. Help keep spending in check by planning thoroughly and sticking to your plan. Furnishings affect the final cost of the project; custom-made furniture will push up the price. Also, make the most of your designer's contacts, ask for contractors or suppliers they are familiar with, as the project will run more smoothly and is likely to be more economical.

Finishing touches Double-check that your designer will be happy to answer any queries that arise even after the project is finished. It's also a good idea to ask for any receipts or guarantees for the furniture and fittings. Your interior designer should see the project through to the end, styling the room to look its best. Ask how to make the most of your room scheme to keep it looking great.