I have a timber frame house, built about 10 years ago. I would like to install a back boiler behind my sitting room fire. However, the responses I've got so far is that the cost would be about €15,000, or that it is not possible because the chimney would have to be double lined due to risk of timber frame structure catching fire. Any advice or options welcome. Has anyone else come across this problem in timber frame house, and how good or bad is the above quote? Thanks.