When I read about truss roof structures, I get the impression that they are meant to be self-supporting. Is this something one can always assume to be true, or are there exceptions? Can I assume that yellow-marked walls are safe to demolish, or do I still need to consult an engineer? I estimate the length between the original outer walls to be about 8m. The house is from the 1960s. An extension has been made to the house where the outer walls have been moved out in two of the rooms and a new beam has been installed instead, so I assume this should not affect the basic construction. Let me know if further information is needed to make a judgment, and I can provide drawings if necessary. Thanks for your help!
The highlighted walls are likely not load-bearing, with the exception being if there is a beam in the living room ceiling.