1. Are BOTH purchases and refinances of 1-4 family residences that are located on 25 or more acres exempt from HMDA reporting?
2. Is a refinance HMDA reportable whether the new lien is a first or a second lien?

1) Acreage only pertains to Reg Z & RESPA; it has no bearing on HMDA.

2) If the new lien is "new money" and not existing debt secured by a dwelling (not necessarily the same dwelling), it is not HMDA reportable. To illustrate, Mr. Customer has a first lien on his home for $100,000. He just obtained a second lien on the home for $15,000. The second lien would not be reportable (because no dwelling secured debt was refinanced, the $15,000 is new debt). However the $15,000 second lien would be HMDA reportable if the funds are being used for home improvements to be made.

Your new lien can be reportable if you are paying off a loan at another financial institution that was to same borrower and also secured by residential real estate. That would be a refinance.

In regards to the acreage question - from the Getting it Right guide:

Farm loan. A loan to purchase property used primarily for agricultural purposes is not a home purchase loan even if the property includes a dwelling. An institution may use any reasonable standard to determine the primary use of the property, such as by reference to the exemption from Regulation X (Real Estate Settlement Procedures, 24 CFR 3500.5(b)(1)) for a loan on property of 25 acres or more. An institution may select the standard to apply on a case-by-case basis.

Hope this helps!