Car Park Ventilation Fan Energy Savings

Hi, on a recent project we were requested to provide evidence that 5 buildings built within the last three years did not have carbon monoxide sensors installed in the basement car parks in order to claim any savings. We followed and referenced the methodology outlined in the Advanced Energy Modelling For LEED document produced by the USGBC. Is it always a requirement to provide evidence as per above since the baseline building does not have any controls for basement parking fans? I was also under the impression that guidance referenced in the Advanced Energy Modelling Guide would be 'official' and no further justifications required if the method of calculation is clearly outlined.