Castelvecchio Museum
Restoration by the architect Carlo Scarpa,

um, lots of loft renos in seattle, san fran, chicago, montreal, vancouver, new york, baltimore, boston...

the early work of onion flats (philly) comes to mind as well.

how bout the tate modern by herzog demeuron?
how bout the museum in hamar by sverre fehn?

there are really soooo many examples of what you're asking...it's amazing to me that you're not able to find any. don't people look through books and magazines anymore?

why look in magazines or even google when there is archinect ;-)

british museum

Thanks everyone for the great responses! It really helped me get going and was exactly what I was looking for! I really appreciate your help!

arr>> Its kind of funny because that is one of the exact examples I
was thinking of but couldn't remember the name. I had been
there two years ago and the name of the place just slipped my
mind, so thanks alot!

larslarson>>I admitt that I don't read magazines or books as much as
I used to. Its cheaper and easier to go online nowadays.
And the reason I couldn't find any images online was
because I think I wasn't typing in the right keywords. After
I started using repurposing old buildings, I found a bunch
of examples.

i am waiting for those modern exterior with traditional interior gigs...

the norman foster building in ny, the triangulated skyscraper, forgot the name, it is built inside of an old building, pretty cool, but the bastards don't let general public in beyond the lobby :(

^ Hearst Tower?

so many residential firms in NYC specialize in this. especially ones who do townhouse renovations. www.stevenharrisarchitects.com for example.