Here’s what to look for on the house plans.
House plans are most useful. The designer will have identified the load bearing walls, beams, posts and pillars. If any of these elements have been removed or modified then this should raise a caution flag.
The attic framing is either stick built rafters (site built from dimensional lumber) or pre-manufactured off-site trusses.
Rafters may not have a continuous bottom cord and may require several lengths of lumber to span the width of the floor area below. At the overlap of this lumber, a load bearing wall is required below it.
Trusses on the other hand, are an engineered product, designed to span across their entire length and do not usually require any intermediate supports.
If the house has multiple levels, then the load bearing walls will all be in alignment on every level. This is essential for load transfer from every floor above to the foundations aiednd footings below ground.