ᐅ Penthouse apartment on an existing bungalow

Created on: 30 Jan 2013 12:39
D
DaSt
D
DaSt
30 Jan 2013 12:39
Hello everyone,

I hope this is the right thread for my question...
I might have the opportunity to add an additional floor to my father’s one-and-a-half-story bungalow (about 210sqm (2,260 sq ft)).
I visited the local building authority to check if this would generally be possible, and it turned out not to be a problem at all.
After that, I went to a few prefab home manufacturers who offer this kind of service and received some rough cost estimates. The average price was around €310,000. Does this seem realistic? I had personally expected around €300,000...

Another potential issue is the bungalow itself, as it used to be a retail store in earlier times. Unfortunately, the original building plans never included the large basement area (about 500–600sqm (5,380–6,460 sq ft)). What kind of problems could this cause (structural integrity would of course need to be checked by a structural engineer)? Is it possible to have this approved retroactively by the building authority? If so, what additional costs might we expect?

Thank you in advance & best regards