N.Y. Comp. Codes R. & Regs. tit. 16, § 463.4
(a) The cost of construction properly includible in the steam plant accounts shall include, when applicable and when actually incurred, the direct and overhead costs as listed and defined hereunder:
(3) Materials and supplies includes the purchase price at the point of free delivery plus customs duties, excise taxes, the cost of inspection, loading and transportation, the related stores expenses and the cost of fabricated materials from the utility's shop. In determining the cost of materials and supplies used for construction, proper credit shall be made for unused materials and supplies, for materials recovered from temporary structures used in performing the work involved, and for discounts allowed and realized in the purchase of materials and supplies.
Note:
The cost of individual items of equipment of small value (for example, $200 or less) or of short life, including small portable tools and implements, shall not be charged to steam plant accounts unless the correctness of the accounting therefor is verified by current inventories. The costs shall be charged to the appropriate operating expense or clearing accounts, according to the use of such items, or, if such items are consumed directly in construction work, the cost shall be included as part of the cost of the construction.
(18) Interest during construction includes the net cost of borrowed funds used for construction purposes and a reasonable rate upon the utility's own funds when so used. Interest during construction shall be charged to the individual job upon which the funds are expended and shall be credited to account 536, Interest Charged to Construction—Credit. The period for which interest may be capitalized shall be limited to the period of construction. No interest charges shall be included in these accounts upon expenditures for construction projects which have been abandoned. (See paragraph [17] of this subdivision.)
Note:
When a part only of a plant or project is placed in operation but the construction work as a whole is incomplete, that part of the cost of the property placed in operation shall be treated as “steam plant in service” and interest thereon as a charge to construction shall cease.
(19) Earnings and expenses during construction. The earnings and expenses during construction shall constitute a component of construction costs.