I have done building footting design, which need to be revised as per instruction given below.
Civil expert is required
Steps proposed are
Set your calculations out (similar) to this way.
Measure the roof area.
19.23mtrs x 6.00mtrs = 115.38m2
Calculate the live and wind loads and multiply by (1)
115.38 x 1.7 = 196.15 kN
Calculate roof sheeting and multiply by (1)
17.2 is what we were given as the weight /m2 x 115.38 = 1984.54 N x (Gravity 9.81) = 19468.30 then divide by 1000 = 19.47 kN
Rafter is 610UB weighs 125kg/m therefore 19.230 x 125 = 2403.75 N x (Gravity 9.81) = 23580.79 N then divide by 1000 = 23.58 kN
Column is 321 x 309 UC that weighs 137 kg/m therefore 6.00 x 137 = 822 x 9.81 = 8063.82 divide by 1000 = 8.06 kN
Footing is .8 x .8 x .8 = .512m3 x 2400kg/m3 = 1228.8 x 9.81 = 12054.53 divide by 1000 = 12.05 kN
Now add up all coloured boxes to give you the amount of load in kN on the soil.
Now using soil report check bore hole near grid ( I think it is bore hole #2) what is the bearing capacity.
Recalculate a concrete pad maybe deeper and/or wider to get a to bearing capacity of what you have calculated.