The treatment of hand tools and all of the other items previously included within the working areas overhead percentage in NEC3 ECC has changed in NEC4 ECC, which has removed that percentage altogether. Instead, these items will now be paid for, if at all, under the relevant headings of the schedule of cost components, namely equipment, plant and materials, subcontractors, and charges. Hand tools, just like any other tools, will usually be included in the definition of equipment and are paid for as such. But they are only paid to the extent that it has been paid for by you. If a carpenter turns up on site with their own hand tools and uses them, that will not have cost you anything and therefore nothing will be paid under this item.