{
  "cavity_wall_insulation": { "unit_cost_per_m2": 18.5 },
  "loft_insulation": { "unit_cost_per_m2": 12.0 },
  "sloping_ceiling_insulation": { "unit_cost_per_m2": 40.0 },
  "flat_roof_insulation": { "unit_cost_per_m2": 60.0 },
  "suspended_floor_insulation": { "unit_cost_per_m2": 25.0 },
  "solid_floor_insulation": { "unit_cost_per_m2": 45.0 },
  "mechanical_ventilation": { "unit_cost_per_m2": 450.0 },
  "external_wall_insulation": { "unit_cost_per_m2": 100.0 },
  "internal_wall_insulation": { "unit_cost_per_m2": 90.0 },
  "double_glazing": { "unit_cost_per_m2": 600.0 },
  "secondary_glazing": { "unit_cost_per_m2": 510.0 },
  "low_energy_lighting": { "unit_cost_per_m2": 8.0 },
  "high_heat_retention_storage_heaters": { "unit_cost_per_m2": 3500.0 },
  "air_source_heat_pump": { "unit_cost_per_m2": 12000.0 },
  "gas_boiler_upgrade": { "unit_cost_per_m2": 3000.0 },
  "system_tune_up": { "unit_cost_per_m2": 500.0 },
  "system_tune_up_zoned": { "unit_cost_per_m2": 900.0 },
  "solar_pv": { "unit_cost_per_m2": 0.0 },
  "secondary_heating_removal": { "unit_cost_per_m2": 250.0 }
}