Dduallt is an unusual example of the 'unit-system' of linked dwellings, in which two parallel ranges are linked by a storeyed lobby giving independent access to each. The precise relationship between the two ranges is uncertain, but the rear range of Snowdonian type is likely to be the earlier of the two on architectural grounds. The front range probably served as a parlour, but the layout suggests that it might also have been, on occasions, as a small separate dwelling. A barn or byre attached to the rear range is a
later addition. The house was restored by Colonel Campbell in the 1960s when it was extensively renovated. See the discussion of the unit system in Vernacular Architecture 38 (2007), pp. 19-34. Plan and perspective sketch published in Houses of the Welsh Countryside (RCAHMW, 1975), fig. 85.
(RFS/RCAHMW/APRIL 2011).


[Additional:] Tree-ring dating commissioned by North-West Wales tree-ring dating project in partnership with RCAHMW in 2010/11.
The west range was found to be the earlier of the two parts of the house, as expected. However, the felling dates for this section were widely ranging from winter 1559/60 to the spring of 1565, with a further timber dating to 1567-92. The evidence suggests that the west range was probably completed in its present form by the late 1560s. As to the East Range, many of the timbers were fast grown with insufficient rings for successful cross-dating. Of the four out of five timbers dated from this range, only two retained complete sapwood. These were the first floor tiebeams, one of which was found to have been felled in the spring of 1600, whilst the other was felled in the winter of 1604/5. Therefore, it is most likely that this range would have been constructed in or shortly after 1605. Full report available in NMRW. (NJR, 07/04/2011)

[Additional:] Tree-ring dating reported in Vernacular Architecture 42 (2011). (RFS/RCAHMW/JULY 2011).