If you are out and about in Brooklyn and happen to look up from time to time, you might notice what seems to be a plague of new floors being added to old buildings. The good news, of course, is that from street level, you have a renovated and restored old building. The bad news is that if you look up, the building has sprouted a mutant thing on top that sometimes clashes in a hideous way with the original structure.

We offer as cases in point a couple of small examples, one of which we have dealt with a bunch because it’s the building that has been dubbed the Carroll Gardens Hell Building. That’s a rendering of the Carroll Gardens Hell Building to the right. If you ride the F Train, you can’t miss the thing, nor can it be missed from anywhere on virtually any street in Gowanus. It’s got a two-story steel framework on the roof. The website says “the original spirit of the building was maintained.” We don’t have a degree in architecture, but we do have eyes and we’ll simply say this about that: We don’t think so.

The other is a building we’ve watched for a long time in Williamsburg called the Wythe Avenue Lofts. In both cases the work comes out of the shop of Robert Scarano. Mr. Scarano, however, is not the only architect working in Brooklyn who’s doing “additions and alterations.”

We’ve been watching the Wythe Avenue Lofts as it’s gone through a very slow renovation process and sprouted its own massive growth on top. (Although the tumor atop this building appears tiny compared to the Carroll Street one.) You might recognize the building due to all the graffiti and tagging on the upper floors. (The building is next to the “People’s Fire House,” the Williamsburg fire station that was closed with great controversy by the city.) In any case, the finished building will have 56 apartments and the completion date is listed as 2008, which would make a two-year project from start to finish.