Table 1 Financial costs and carbon conversion factors for health care use and other assumptions made

 A&E attendance

£113 ^b

 OPD appointment

£135 ^b

 Physical health cost per bed-day

£399 ^b

 Mental health OPD appointment

£100 ^b

 Mental health cost per bed-day

£430 ^b

 GP consultation

£45 ^b

 Bus journey

£2-assumed

 Petrol

£1.40 / L-assumed

 Cost for travel incl staff and patient travel (from survey)

£8.10/pt/wk (urban)

£3.70/pt/wk (rural)

 Cost of energy

£15.60 / kWh (British Gas standard price)

 ED attendance / one bed day

91 kgCO₂e ^c

 OPD appointment

56 kgCO₂e ^c

 Mental health OPD appointment

59 kgCO₂e ^c

 Mental health cost per bed day for INPT

97 kgCO₂e ^c

 GP consultation

66 kgCO₂e ^c

 Medication conversion factor

0.4 kgCO₂e/£ ^a

 Energy conversion factor

0.5 kgCO₂e / kWh ^a

 Bus conversion factor

0.1 kgCO₂e / mile ^a

 Medium sized car conversion factor

0.2 kgCO₂e / mile ^a

 Carbon footprint for travel incl staff and patient travel (from survey)

9 kgCO₂e/pt/wk (urban)

7 kgCO₂e /pt/wk (rural)

 Average fuel consumption for car

60mpg

 Type of car used

Small average car size

 Total area of all treatment rooms and office space used by TC

185 m²

 Carbon footprint per square metre of outpatient room

147kWh/m² annually

 Duration of equipment used

5 years

 Cost of laptop / easy chair / desk chair / desk

£400 / £200 / £400 / £150

 Salaries of staff

Taken as average salaries ^b

 Staff time dedicated to therapeutic community intervention and number of patients in service at any given time

Estimated by director of service