Homeowners struggle to properly install PVC windows in double-brick cavity walls without professional help

DIY homeowners attempting window replacement in double-brick construction face confusion about proper installation techniques, insulation requirements, and building code compliance. Current solutions (hiring expensive contractors or relying on incomplete online guides) leave people uncertain about whether their installation will be weathertight, energy-efficient, and structurally sound, risking costly water damage, drafts, and failed inspections.