Addition around existing brick chimney

[Adenmoor]

Hello all,
I've been working on an addition to my house.

We are keeping an existing fireplace with a brick chimney. I have already framed around the chimney but still need to have the existing chimney extened about 5 feet.

The chimney used to be outside the house but will now be enclosed. Is there anything special I need to do with the chimney itself?
I've heard that I need to demo down to about two feet of rebar before adding back upward. Is this true?
Is it possible to frame a new chimney made of wood built ontop of the existing chimney?

I live in Los Angeles County.
Thanks!

[Daniel O'Connor]

I think if you have to extend your chimney you should use fire brick. If you used wood, you might have an accident.

[Teetorbilt]

I saw how to do this somewhere, Try TOH archives.