Drwy gysylltu trafodiadau preswyl â ffynonellau sy'n amcangyfrif y stoc o eiddo preswyl, megis niferanheddau'r dreth gyngor(data awdurdodau lleol) neuddata stoc eiddo y dreth gyngor(Asiantaeth y Swyddfa Brisio), gallwn hefyd nodi ardaloedd lle mae cymharol fwy o drafodiadau, er enghraifft.
By relating residential transactions with sources that estimate the stock of residential property, such as the number ofcouncil tax dwellings(local authority data) orcouncil tax stock of properties data(Valuation Office Agency), we can also identify areas where, for example, there are comparatively more transactions.