The definition of "higher-priced mortgage loan (HPML) starts section 1026.35(a) of Regulation Z:
"(1) "Higher-priced mortgage loan" means a closed-end consumer credit transaction secured by the consumer's principal dwelling ...."
A lot loan does not include a dwelling. Therefore it cannot be an HPML.
Definitions are the skeleton on which all the rest of Regulation Z is hung.