Like in a flute, guitar or violin, the air mass inside the bandura resonates when excited by a string or other outside stimulus. A man by the name of Helmholtz was the first to characterize this phenomenon, hence the name. This ones kind of funny for some reason, it seems that light instruments in general sound better over all than heavy ones. One theory is that if an instrument is over-built, it doesn't sound as good as one properly built. The current practice of carving out poltavki from solid wood seems excessively labor intensive and wasteful.
Wood is a finite resource.
Good wood is very difficult to find. To make the instrument more cost and resource conscious, a more Lviv type approach would be necessary. By drawing up a plan in a 3D CAD package, I was able to work through problems before they happened. Full size plans are also critical for the creation of templates. Also, once these plans are finalized, others can build this design.