London Builders

If possible, start by getting a referral from family or friends who have recently had work done.
Ask for help from respected trade bodies

Contact your local builders association and ask for a list of registered members. The National Federation of Builders has 14 offices around the country which can provide you with a list of registered builders in your area.
Obtain estimates

Ask two or three builders for estimates in writing. Ask them to confirm whether there is any planning permission required for the work.
Ask for references and check them

Ask each builder for two or three references from previous customers. Contact these people and find out how happy they were with the work carried and the builder’s conduct. If possible go and view some of the work.
Find out if the builder belongs to a respected trade body

Ensure the builder belongs to a respected trade organisation as it will have membership standards and requirements. Don’t forget to make a call to make sure membership is current.
Agree the work and put it in writing

You should make an agreement or contract in writing with your builder. It should outline the work to be done, date of completion, security and safety, catering and lavatory arrangements, disposal of waste materials, hours of working and so on.
Insurance

Ask to see the builder’s public liability insurance certificate. Also, the building work may affect your home and contents insurance – contact your own insurance company.
Deposits and Payment

Deposits are usually only payable where specific or custom-made materials are required or where the project will take a long time to complete. Otherwise, avoid paying deposits, and agree any payment schedule in writing.
Beware the VAT-free ‘deal’