Any work requested for external contractors is considered extraordinary cost unless the work required is building maintenance. These costs are recoverable. What determines building maintenance is if the work done is structural, fabric, external doors, windows, glass, flooring, etc.
If a department makes a special request that is above the standard building requirement, this would be considered an extraordinary cost that is to be incurred by the department. E.g. any rekeying of a cylinder, additional electrical wiring, etc. This includes both labour and materials.