The present list includes sampling commissioned by the North-West Wales Dendrochronology Project (in association with RCAHMW). The North-West Wales Dendrochronology Project (NWWDP) is a community-based project which aims to date historic houses throughout the historic counties of north-west Wales. Sampling in Gwynedd (Merioneth and Caernarfomshire) is often difficult because of fast-grown timber, but cross-matching has also suggested that Irish timber may have been imported for building in treeless Anglesey.  

Medieval houses dating from before 1400 remain elusive.  Hallhouses that have been dated are within the ranges already established for gentry and peasant halls. The apparently coeval fireplace and hall-truss at Tyn-llan, Gwyddelwern, suggests that some hallhouses may have had enclosed fireplaces in the early sixteenth century.  The first generation of storeyed houses of Snowdonian type are surprisingly early, pre-dating the general insertion of fireplaces in hallhouses from about 1575.  Several C15th and C16th town-houses were dated in Beaumaris, Caernarfon and Conway, and are a very useful addition to our knowledge of urban buildings.

Detailed surveys of many of the houses sampled are available in the National Monuments Record of Wales (NMRW), the public archive of the Royal Commission.  

The following buildings were sampled but failed to date: 16A/!8 Palace Street, Caernarfon (SH 478 627), Tyn-twr, Bethesda (SH 6220 6690), and Felin Moelfre, Llanaelhaearn (SH 3992 4405) in Caernarfonshire.

Daniel Miles, Michael Worthington, Martin Bridge, Richard Suggett, and Margaret Dunn