Heat does not move only through the broad area of a wall. Junctions at slabs, balconies, windows, and roofs can create local heat-transfer paths through geometry and material changes.
Good insulation cannot compensate for a poorly resolved detail. The designer checks layer continuity, moisture behavior, fixings, and material compatibility, while the site team records concealed work.
When comparing developments, look beyond insulation thickness. Ask for the energy model, standard detail set, window specification, and ventilation strategy. Together, these documents give a more honest view of future comfort.