Regarding dates of the Griffiths' Valuation documents, I've looked at them again and they were various dates.
The image posted in reply 80 has years 1824-1856 on it. Is this from Ancestry or another website?
First the country had to have accurate maps. Detailed mapping of Ireland began in 1820s, the first entire country in the world to be surveyed in detail. Work was done by Royal Engineers regt. That's why they were called Ordnance Survey maps.
Next was assessment for tithes and their collection (and quelling opposition to their collection - more work for soldiers & police). Tithe Applotment Books compiled in 1820s & 1830s, also in National Archives Ireland, free to search.
Then a survey & valuation of land, houses & other buildings in every county in Ireland, beginning with County Dublin. This took a couple of decades. The final completed work was known as Griffiths' Valuation.
I've found 3 records in Griffiths' Valuation for the property Wellington Lodge in Dunleary.
They are all House Books but 2 contain mainly information about land.
1845 December Wellington Lodge, Kingstown School, Reps. of late Mich McCaul. Note says "This lot should come after Robert Farrell's on foregoing pages. Built a schoolhouse & offices. Lease rent £140."
1847 lot 54 Reps of late Mich McCaul Wellington Lodge. House, offices & garden, School House. Property on opposite page is Mary Villa, Robert J. Farrell.
1849 was the one found by Baz reply #80 which lists each building. I couldn't find it by searching for McCaul or variants I tried. Got it by looking for Robert Farrell (or was he Ferrell) + County Dublin + Dunleary townland. Robert was under Monkstown parish in 1847 book and Dalkey parish in 1849 book. Robert's address was Mary Villa in 1847 and York St. in 1849. He was next door to Wellington House all the time so he hadn't moved, the parish boundary may have altered or the surveyor made a mistake.
census.nationalarchives.ie/search/vob/home.jsp
The image in reply #80 was complete when I looked at it second time, no letters missing from edge this time.
I was looking for something else in Chief Secretary's Office Registered Papers and noticed a letter from a young man in York St., Kingstown c.1825, saying he'd recently begun studying theology at Trinity College Dublin. The lad had a long posh name. He may have known the McCaul family.
https://csorp.nationalarchives.ieSearchable by key word and can filter by year. If filtering by year, select year before putting keyword into search box or the word disappears.
A new attraction which arrived in Dunleary/Kingstown while Mr McCaul lived there was a prison hulk in the harbour. Several local doctors applied to be ship surgeon. There were occasional convict escapes. Even more exciting was the arrival of the railway in 1834, the first passenger railway in Ireland. More news to make headlines was King George IV embarking at Kingstown in 1821. RootsChat member Killiney History posted a link yesterday to fresh articles on Killiney History website. Royal visits featured.
P.S. No need to quote entire posts in replies. Just say which post number you're replying to or quote the relevant part.