unfortunately if you want to read the papers published by the BRE or british standards to make an informed decision and not just be lead by uniformed people on the inernet, then you will have to pay for them
from what i understand, and i may have this wrong, in addition to BRE finding real world problems and measuring them in a prescribed manner, they also built masonry and blockwork piers in trays of water and left them there for months so that they could take readings in a contolled environment.
i think damp in houses is caused by lots of issues, external ground levels, external render, internal humidity, leaky roofs gutting or pipes generally, blocked cavities, the list seems endless.
tackle everything else first, and if there is still a problem, maybe it is rising damp, after all BRE (who dont make money from people installing damp proof couses) seem to have proven it exists?
just dont believe the guy who only checks for rising damp with a hand held electrical meter and then tries to sell you an injection damp proof course, always get a second or third opinion