The eaves junction that failed the Part L check
Drawn: A standard dormer eaves with insulation shown 'continuous' but no room for the specified depth where the rafter meets the wall plate.
On site: The insulation pinched to half its depth at the eaves — the exact spot a thermal-imaging survey would flag — and there was nowhere for the cold-bridge break to land.
The fix we built: We raised the wall plate detail, ran a rigid insulation upstand and used an accredited eaves detail so the line of insulation is genuinely continuous. The psi-value passed without upgrading everything else.