Missed building details

[Matthias84]

Even if thats not a problem of O2W, during my surveys in Rostock I noticed a few simple things missed to bring characteristics to buildings:

• pillars (with describing their shape, height and connectivity)
• roof overlengths (that could become a simple roof:overlength=0.3 to affect the whole building)
• roofs that already look aside on the sides of the top level and so are very steep
• balconys (unkown if this a real building part, as to me it has a more outdoor characteristics. Anyway they are mostly very colourfull and allow a quick recognition)