raising roof

[R.Reynolds]

I just had a client call in a change on a project thats nearly done....(#%#!!!) wanting to raise all walls from 9 ft to 12 ft..

I had no trouble increasing wall heights in elevation view.. but cannot seem to raise the roof to match.. I have deleted and redone the roof.. tried the transform-replicate object and the z-plane.. .. its not the effect I needed ..I realize now that this raises and lowers planes and not the roof proper( from what I gather)
The reference manual on page 307 shows a 'change roof pitch or height.'. saying it will appear when you"attempt to snap the corner or edge of a roof plane near the edge of another roof plane whcih does not match vertically"..
My roof is a single level gables 6/12 with several wall bump-outs and gables above each.. and has no other plane vertically..
I m sure this is something where I cant see the trees for the forest.. but cant seem to find anything in the threads, or help
data base.. etc
appreciate any suggestions..
thanks all..
Randy