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Reviewed 22 September 2026EWI and retrofit sequencing
Why moisture, ventilation, junctions and services should be assessed before external insulation.
A retrofit plan should understand the existing wall, moisture exposure, roof and ground junctions, windows, rainwater goods, services and ventilation before choosing an EWI system.
Sequence repairs and water management first, then coordinate insulation, reveals, sills, eaves, plinths, openings and external services. A new finish cannot cure unresolved leaks, movement or damp.
Use one compatible system and its current details; do not combine generic products or promise a performance result from insulation thickness alone.