the cost of staff (whether salaried or non-salaried) employed directly by the claimant calculated in accordance with regulation 7;

the costs payable to a contractor engaged by the claimant;

the cost of materials;

the cost of hiring equipment, plant and vehicles or, where the equipment or plant is, or vehicles are, leased to the claimant, the equivalent cost based on relevant market rates; and

other costs which are relevant and specifically attributable to a chargeable job.