Is your crack serious? Four factors decide it: width (over ~5mm matters), direction (diagonal/stepped beats vertical hairline), behaviour (growing or reopening beats static), and company (sticking doors, sloping floors, external mirroring). This checker weighs your answers the way an initial triage would — it guides a decision to monitor or assess; it cannot diagnose.
Five-question triage
Important: this tool provides general, indicative guidance only. It is not a survey, a diagnosis or a quotation, and it cannot assess your specific property. Figures are broad London planning ranges; the appointed professional confirms actual fees and any repair costs are confirmed by contractors pricing an engineered specification. If you are concerned about your property, request a structural assessment or call.