A raised-heel truss is much like it sounds: the heel of a conventional plated roof truss, where the bottom chord intersects with (and bears on) the perimeter wall plate and is fitted with a vertical member that literally raises the top chord of the truss.
What is the primary advantage?
More Insulation Reduces Your Energy Costs
The primary advantage of raising the heel is to allow full-depth, uncompressed wall-to-wall insulation of the attic floor. Combined with a properly designed attic ventilation system and some well-placed air sealing, a roof framed with raised-heel trusses reduces the temperature and pressure differences between the conditioned living space below and the unconditioned attic area, thereby reducing thermal transfer (or A/C loss) between those spaces. Industry experts agree this is the right way to build.
Consistent ventilation is a critical element of a raised-heel roof system to help regulate temperature and pressure differences between the attic and the living spaces and thus achieve full energy-saving and moisture-mitigating value.