The requirements would depend on the type of calibrations you are performing. The point is to have climate and temperature control, along controls over any other parameters that influence the accuracy and uncertainty of the calibration on hand. This could be electromagnetic disturbances, radiation, dust, sound and vibration. Consider for example mass calibrations – a draught, dust and vibration free environment is critical. For volume, it is temperature is critical (usually 20.0°C). Typically the tolerated range would be between 20 and 25 °C with relative humidity at 35 to 50% . ISO 17025:2017 does not provide specific requirements, but it requires calibration laboratories to consider and mitigate risks and control facilities (room type) and environmental conditions (such as temperature, humidity) to meet the criteria for the type of calibrations being performed.