Double Glazing Company

Try to visit a showroom, get references and/or view previous work carried out by the company. Alternatively, ask to speak to other customers on the telephone. Of course, the double glazing company is going to give you a referee that will be complimentary.

Try and ask specific questions such as:

Did they turn up on time?
Was anything missing and how quickly was this rectified?
Did they leave the site clean and tidy?
Did they fix any snags in good time and without fuss?

Every job has it problems, so be realistic in what standard of review you'll accept. The main criterion is:

Was the customer happy with the work done, and would they use them again?

A 10% deposit is normal. A larger one is appropriate only if the work is 'bespoke' - such as unique timber window designs. Try to pay in stages according as the work in completed, and withhold the final payment until the work is completed to your satisfaction

Examine guarantees carefully. Double glazing companies offer 'insurance backed' guarantees which are really insolvency guarantees and only become effective if a company goes bust. Most guarantees will give a ten-year cover on the frames but you may find that the cover for double glazed units is five years.