Just so that some of the newer beekeepers don't get the idea that
this (replacing all your combs as fast as you can) is unanamously
accepted, I want to say that I think it can be a dangerous idea.
 
It is hard to argue with cleanliness -- after all it's next to
godliness -- and I'm sure many are attracted to the easy arguements
to be made for it.
 
HOWEVER, in my own experience, I found that as I *reduced* the amount
of comb that each colony was required to build, my wintering success
and overall colony health *increased*.
 
Comb building beyond a point is hard on bees most times of the year
and has a cost in honey production.  In some years, a lot of comb can
be built.  In other years, little can be accomplished.
 
If you have committed the bees to a lot of work in a bad year, the
wintering will suffer greatly -- here in the north. I can't speak
for the south.
 
For me, 10% (average) is a safe amount of brood comb to replace any
year.  Some hives will do more, some cannot even do that.  Swarms are
quite happy to do a lot more.
 
Additional foundation can be placed in the supers, and used later in
the brood chamber if drawn, however, if wax foundation is not drawn
the first time it is put out, it tends to get ruined -- warped and
broken -- so we restrict ourselves to what we know the bees will do
for sure.  Plastic frames and foundation allow for putting more
sheets in the supers, because it can come and go from the field
several times without damage and loss of attractiveness. (It isn't
attractive in the first place :)
 
In my area, an agressive brood comb building program undertaken
without great care and understanding can be beekeeping suicide.
 
FWIW