https://durrushistory.wordpress.com/late-18thearly-19th-century-house-ahagouna-durrus/

In relation to a lot of the ‘cowlachts’ (ruined houses), there was a pattern to the building. By noting the placement of main stone over the front door and flag it is is often possible to see it as the work of particular builders or put an approximate date. Very often the stones have beeb recycled but a stump is often left or a residue foundation often covered by grass.