The Enviro-Flame website gives phone number for a 'free estimate'. I sent the company photos and explained in an email fairly clearly what we have in mind. As we can't know what is possible until a technician visits our house, I was told that this would cost £65 to conduct a survey (or alternatively, having two chimneys cleaned at a cost of £160 and advice on the possibilities). I then received an invoice for £160 due for payment the day before the engineer comes to our house. I find it extraordinary that this company wants to be paid to provide a quote for what is likely to worth several thousand pounds in business and expect an invoice to be settled before they provide the service. I will not be using this company.