one other question, our fireplace is not built on a raise hearth and since we do not want to replace the mantel and marble surrounds, we would have to build a base to support the part that sticks out of the fireplace. Is there anyone with a similar situation? Many thanks again.
Bill

5 grand seems expensive to me. Have you shopped around at all?

If you're having it installed, just throw it on the installer. Hell, for 5 grand, make it their responsibility to make sure the thing fits. Certainly don't vouch for the space before they get there.

Whatever insert you decide to purchase ALWAYS have the installer or shop come out to make sure that it will fit first. If it does not, then the installer either cannot install that particular unit or they must be prepared to do some demolition to the fireplace at the install or prior to it. It is NOT a good idea to spring up any surprises on installers. They might just walk away and then you won't have the unit installed-ever. Giving this unusual year, the installers and the shops will walk away from jobs they do not want just because they can and they have 12 other people standing in line wanting your appointment.

We just put one in an exsisting fireplace - our fireplace was odd sized...and the insert didnt fit exactly so we had a piece of slate cut to slide in behind...the thing really cranks...keeps my entire house ( 2800 sf) warm...We had a hearth that stuck out and it just fit on it- you would need something there. We paid about the same amount.