Windmill House Llantwit Major · Vale of Glamorgan · Wales

Windmill House stands about 900 metres north-west of the Church of St Illtud at Llantwit Major, in the direction of Llanmaes. It is the converted survival of the former Frampton Windmill, a tower windmill that stood in a circular enclosure on the north-western edge of the historic town.

The windmill was probably built about 1820. Arthur Riddle, a Cardiff millwright who also built Boverton Mill, has been suggested as a possible builder. The mill's working life appears to have been short. The last grinding was made about 1848, and the windmill itself was not shown on the 1840 tithe map, although the circular enclosure in which it stood was marked.

By the time of listing in 1980 the surviving historic fabric was the three-storey conical tower of coursed squared limestone rubble. The cap, internal floors, and machinery had gone. The associated range was then much lower, and the building was undergoing restoration and conversion. Subsequent works substantially altered the structure: the tower was raised to five storeys, a roof-top viewing platform was added, and the attached stone range was rebuilt and heightened. The additional masonry was carefully matched to the earlier work, preserving the landmark character of the former mill.

Windmill House was listed at Grade II on 10 March 1980. Its special interest lies in its survival as a former windmill tower in an area where watermills were historically more common, and in its continuing local landmark value after conversion.