{"success":true,"calculator":"insulation","inputs":{"area_sqft":1500,"target_r_value":38,"insulation_type":"fiberglass-batt"},"results":{"insulation_type_label":"Fiberglass Batts","required_depth_inches":11.9,"volume_cubic_feet":1484,"estimated_cost":1200,"estimated_rolls":38},"formula":"Depth (in) = Target_R ÷ R_per_inch; Volume = Area × Depth ÷ 12","notes":"Fiberglass Batts: R-3.2 per inch."}