If you don't have a preapproval program, they are prequalificaitons. HMDA is not "triggered" by prequels. Don't report.
No house = no HMDA (for you).
Here's the citations to support this:
A prequalification request is a request by a prospective loan applicant (other than a request for preapproval) for a preliminary determination on whether the prospective loan applicant would likely qualify for credit under an institution’s standards, or for a determination on the amount of credit for which the prospective applicant would likely qualify. Some institutions evaluate prequalification requests through a procedure that is separate from the institution’s normal loan application process; others use the same process. In either case, Regulation C does not require an institution to report prequalification requests on the loan application register, even though these requests may constitute applications under Regulation B for purposes of adverse action notices. [Commentary to §1003.2(b) #2]
A request for preapproval… is an application under this section if the request is reviewed under a program in which the financial institution, after a comprehensive analysis of the creditworthiness of the applicant, issues a written commitment to the applicant valid for a designated period of time to extend a home purchase loan up to a specified amount. [§1003.2(b)(2)] To be a preapproval program… the written commitment… must result from a comprehensive review of the creditworthiness of the applicant, including such verification of income, resources, and other matters as is typically done by the institution as part of its normal credit evaluation program. [Commentary to §1003.2(b) #3]