D.C. Mun. Regs. tit. 9, § 510
510.1 On construction loan deeds of trust or mortgages and permanent loan deeds of trust or mortgages, the amount of consideration for the purposes of the tax imposed by the Act shall be an amount equal to the principal amount of indebtedness.
510.2 In any case in which the amount which may be secured under the deed of trust or mortgage is not ascertainable, the tax shall be based upon the fair market value of the property conveyed, determined as of the date of the deed of trust or mortgage, but including the value of any realty required by the terms of the deed of trust or mortgage to be constructed on the property.
510.3 Within thirty (30) days after the execution of a deed or other document by which a security interest in real property is given pursuant to a construction loan deed of trust or mortgage or a permanent loan deed of trust or mortgage, all transferees of secured interests shall record a fully acknowledged (notarized) copy of that deed of trust or mortgage, including the lot and square number of the real property transferred or encumbered, with the Recorder of Deeds.
SOURCE: Final Rulemaking published at 27 DCR 4929 (November 7, 1980), incorporating text of Proposed Rulemaking published at 27 DCR 3347, 3348 (August 1, 1980).