The trail begins with the Civil Survey of 1654 to 1656, a comprehensive Cromwellian-era document that recorded land ownership and property across Ireland following the upheavals of the 1640s. Among its entries, noted by Robert Simington in his 1945 edition of the survey, is a reference to a thatched house at Jamestown. A decade or so later, the Hearth Money Roll for County Dublin, dated 1664, offers what may be a more specific glimpse of the same property. The Hearth Money Roll was a tax levied on domestic hearths, meaning the number of chimneys in a dwelling indicated something of its relative comfort and status. The entry recorded by Cary in 1930 to 1933 names Edward Ellis as the owner of a house with two chimneys at this location. Two chimneys in the 1660s was not the mark of a grand estate, but it placed the household a step above the single-hearth cottages that made up much of the rural landscape. Whether Ellis's house and the thatched structure from the Civil Survey are one and the same building cannot be confirmed, but the geographical coincidence is suggestive.

Jamestown Great lies in County Dublin, and the present Jamestown House may sit on or very close to the footprint of this earlier structure. The record, compiled by archaeologist Geraldine Stout and uploaded to the sites database in August 2011, is careful to use the word 'probably' when connecting Ellis to the Civil Survey entry, which is a reasonable caution given the documentary gaps involved. For anyone with an interest in early modern Irish domestic life, the site is worth a quiet moment of consideration, even if nothing visibly old remains above ground. The value here is less in what can be seen and more in understanding how fragmentary the evidence for ordinary houses of this period tends to be, and how much depends on cross-referencing a handful of surviving administrative documents.