Lowering a firebox

Question from Mike: 

I have a house with a stone fireplace that starts in the basement with one fireplace opening and also has fireplace in a raised floor living room upstairs. I want to lower the raised floor by three feet. The ends outside look like square clay pipes. Can the upstairs firplace firebox be lowered? 

Jake's answer: 

Mike, Yes, it can be lowered. It will most likely require you to dismantle the chimney down to the new firebox level and rebuild the fireplace from the new floor level on up. If you live in a ranch style house (one story) this may not be too big an undertaking. If you are in a two story, the project will be a little more involved. It would be a good idea to have a qualified mason take a look at it. You can usually find a good mason at the local brick and block supplier. Check his/her references out before engaging them in the job.