Mislim da nije baš najkoretnije reći “(ne)opterećeni vlasnik” - nije vlasnik pod opterećenjem, već njegova imovina (pod hipotekom).

Business Definition for: unencumbered property
- Dictionary of Real Estate Terms
unencumbered property
real estate with free and clear title .
Example:Nash owns an unencumbered property. Nash's interest is fee simple , there are no mortgage , vendor , mechanic's , or tax liens on the property, no restrictive covenants exist, and no easements have been granted.
- Dictionary of Business Terms
unencumbered property
real estate with free and clear title; property owned in fee simple , that is, there are no mortgage, vendor, mechanic's, or tax liens on the property, no restrictive covenants exist, and no easements have been granted.
http://www.allbusiness.com/glossaries/unencumbered-property/...

He was the owner of unencumbered property to the value of about $75,000, and had from his business (the sale of patent medicines of which he was the proprietor) an income of about $10,000 a year.
http://archive.org/stream/newjerseycases28newj/newjerseycase...

Shall be (1) the fee simple owner of unencumbered land upon which the new structure is to be built or (2) the lessee of such unencumbered land under a lease ...
http://books.google.rs/books?id=uhA6AAAAIAAJ&pg=PA49&lpg=PA4...

this purpose shall also be sanctioned to the owner of unencumbered plot. 42. In the instant case as stated by respondent No.3-SRA, ...
http://legaldatabase.in/LegalDB/Home/ExportToPdf?SID=2d5a73d...