Before choosing a double glazing company it is important to be clear about exactly what you want. You will have to think about: style, safety, security and price. It’s also a good idea to check that your local authority will grant planning permission if you are interested in a conservatory or extension.

The double glazing installers should be FENSA registered to ensure that the replacement glazing meets new Building Regulations. Major suppliers should also be members of the Glass and Glazing Federation (GGF).

Do not always opt for the cheap option. Poor quality and/or badly-fitted double glazing can actually reduce the value of your property and you’ll have to pay for the privilege. Similarly it is important to get detailed information about the types of locks and security features on the windows (and ensure that they’re fitted).

Most double glazing companies will ask for a deposit for the work to be carried out. Do not lay down any more than 10% of the overall cost, stay clear of cash (a credit card’s best) and make sure that you get a receipt.

Check the manufacturer’s guarantee and make sure that you know exactly what it covers. A number of double glazing companies offer fairly meaningless ‘insurance backed’ guarantees that are only effective if they go bust.