Why do you want to use Konstruct? One of the advantages of Debian is its package management, which by using Konstruct you would be bypassing. Package management helps avoid the ever present 'dependecy hell' issue and Debian already has the latest packages in unstable(which despite the name, is fairly stable).
If you really have a good reason to use Konstruct, have you checked out KDE's instructions, and if so what problems are you having:
http://developer.kde.org/build/konstruct/
If you don't understand their readme, no offence, but you'll only give yourself more trouble than you want.