paid or incurred for the development of the real property or for the construction of an improvement or additional improvement to such real property, up to the time the development or construction work has been completed. The development or construction work with respect to which such items are incurred may relate to unimproved and unproductive real estate whether the construction work will make the property productive of income subject to tax (as in the case of a factory) or not (as in the case of a personal residence), or may relate to property already improved or productive (as in the case of a plant addition or improvement, such as the construction of another floor on a factory or the installation of insulation therein).
paid or incurred up to the date of installation or the date when such property is first put into use by the taxpayer, whichever date is later.
Thus, an item chargeable to capital account under this section must continue to be capitalized for the entire period described in this subdivision applicable to such election although such period may consist of more than one taxable year.
Example. N Corporation, the owner of a factory in New York on which a new addition is under construction, in 1957 pays its general manager, B, a salary of $10,000 and also pays a New York State unemployment insurance tax of $81 on B's salary. B spends nine-tenths of his time in the general business of the firm and the remaining one-tenth in supervising the construction work. N Corporation treats as expenses $9,000 of B's salary, and charges the remaining $1,000 to capital account. N Corporation may elect to capitalize $8.10 of the $81 New York State unemployment insurance tax paid in 1957 since such tax is deductible under section 164.
26 C.F.R. §1.266-1