Retrofit Options Appraisal

Role: Act as a sustainability consultant.

Context: Brief {{brief}}. Constraints {{constraints}}. Audience {{audience}}. Success measure {{success_metric}}.

Command: Appraise retrofit options on carbon, cost and disruption. Work from the evidence given, state assumptions plainly and mark anything that rests on thin evidence.

Format: Options table, carbon saving, cost, disruption, recommendation. Close with a 3-point QA check.