Symptoms overlap
Condensation is not proof that one wall lacks insulation.
Moisture must be understood
Adding insulation without addressing bulk water or ventilation problems can create new issues.
Energy retrofits are systems work
Air sealing, insulation and ventilation interact.
Use an assessment when the cause is unclear
A whole-house view is often more useful than buying one material based on the coldest room.
Safety boundary. General planning information only. Do not open, dismantle or work on hazardous electrical, gas, structural, fire-protection or contaminated-water systems unless you are appropriately qualified and authorized.