How common are pentagon buildings/rooms?

I read a news article that a 4th century Roman villa was recently [where recently might mean 4+ years ago] discovered near Aberystwyth in Wales.  According to this July 26, 2010 article from the BBC news, “It was roofed with local slates, which were cut for a pentagonal roof.”

Pentagonal roof?  That sounded really cool, though I wasn’t quite sure what it meant and assumed it referred to the shape of the building itself.  The article included an outline of the area, but I couldn’t really tell if it was a pentagon or not.

In searching some more, however, it turns out that the pentagonal refers to the individual pieces of slate.  In the photo on this Heritage of Wales site they explain:

Two pentagonal Roman roof slates from the Abermagwr villa, the one on the right nearly complete. Made from local stone, with square nail holes, these slates constitute what may be the earliest slated roof in mid Wales.

Dang — no pentagonal rooms after all [as a footprint on the Heritage site confirmed], though I bet the roof looked cool anyway.

(Though this roof is from France, published by Arlette1 under GNU-FDL.)

Still, the pentagonal roof question got me wondering how common 5-sided buildings are.  There’s THE Pentagon, of course:

But there are some older examples.  There’s a stone age temple in Sweden according to this article from the Archaeological Institute of America (which actually claims that it is “a near perfect pentagon”).

I also ran across a pentagon room from Flatland by Edwin A. Abbott:

but I feel a little guilty posting it because I haven’t managed to finish the book.  And in it’s current exhibit our Science Museum has a photo of a building that isn’t the Pentagon, but there aren’t any captions so I don’t know what it is.

I had a little more luck with pentagonal rooms.  The  1903 book Roof Framing Made Easy:  A Practical and Easily Comprehended Construction, Adapted to Modern Construction, for Laying Out and Framing Roofs by Owen B. Maginnis has a whole chapter on pentagonal roofs, beginning on page 82, although Owen confesses that “this roof is of a form rarely met with in building construction”.  Incidentally, despite Owen’s claim to make it as simple as possible, I’m thinking simple in 1903 is a tad different than simple in 2010.  [Incidentally, Owen also has a chapter on hexagonal roofs and no fewer than FOUR chapters on octagonal ones, but the heptagonal roof is skipped completely.  Poor heptagon.]

Still, as Owen pointed out, they aren’t exactly common and it makes me wonder if there really just aren’t all that many, or if I just haven’t looked.

Tags: pentagons