You didn't say what the construction on chimney is. If it is a frame construction, with siding on the outside (here I assume the chimney is on an outside wall and protrudes beyond the side of the house). Then, if it is wide enough additional stainless steel chimneys may fit in with only minor siding work. Does day light basement mean the chimney can be carried down to that level in an outside chimney housing? I only start the list of unknowns in the question you ask.

And it is possible to have a wood burning fireplace/insert without a gas-line and burner, just use matches and kindling to start the fire.

Thanks guys. It is frame construction with siding on the outside. Youre correct. Chimney is on outside wall and potrudes outside. It is a daylight walk out basement. It is unfinished. So in the basement I can see the actual framing they put in for a future fireplace. Hindsight being 20/20, I should have had the builder put in the two additional fireplaces before closing. Would have been a heck of a lot less hassle.

baruman

The house we are building has a chimney that has 3 fireplaces inserts that share the same chase. Two of them are back to back (one inside and one outside) - and those are wood burners. The one in the basement is gas.

In my case - the chase could only support 2 woodburners because the flues for these inserts are large (I think 16 inches in diameter) and they must be seperated by a code specifed distance. There are also restrictions on how close the flues can be to the wood framing. So fitting 3 wood burning inserts , with proper clearances, in my case was not possible - even though there was enough volume to house all 3.

They will have to cut holes through each floor to run the flue. Since you have siding it will be easier since they can pull some off and cut access holes to get in.

I know the labor to put in a flue during new construction for us was $600 per unit which included the materials (this is in Northern VA). The fact that they will have to cut in to existing constrcution will cost you more - I would guess a few grand more (just a guess if the work were done in my area).

Make sure you check into the code on the spacing requirements. You might have to go with 1 gas and 2 wood units to make it all work.

I realized at the last minute that since our chase is stoned, adding the basement unit would have been very costly (the 2 upstairs wood burners were always in the plan). So I bit the bullet and put a gas unit in the basement. It was quite a job fitting all 3 flues into the chase - even when it was accessible..

Good luck.