We can also do the same calculation for Dublin 2032 with a few assumptions:
We build 35k (current government target) houses per annum until 2032 nationwide.
Dublin retains the same proportion of those 35k per annum.
Population growth from 2016 - 2022 remains constant from 2022 - 2032.
Last year
Dublin housing stock increased by 12,288 out of 34,198 increase nationwide = 36% of new builds or 12,600 per annum.
12,600 x 10 = 126,000 increase in housing stock by 2032, making total housing stock of 571,280 + 126,000 = 697,280
From 2016 - 2022 Dublin
population grew from 1,347,359 to 1,450,701, an increase of 103,342 - 17,223 per annum.
17,223 x 10 = 172,223. Population in 2032 = 1,450,701 + 172,223 = 1,622,924
Then the 2032 calculation is Housing stock of 697,280 x average household size 2.73 = total housing capacity = 1,903,574
And a population of 1,622,924
Spare capacity is for 280,650 people or 102,802 units (280,650/2.73).
Base rate required spare capacity is 41,836 (6% of 697,280)
Oversupply in 2032 is 102,802 - 41,836 = 60,966
To put that 61k figure in perspective it is almost 4 times higher than the equivalent calculation of oversupply in Dublin using 2011 figures. And back then the talking heads narrative was that it would take decades to mop up the excess. And obviously prices had reacted accordingly.
Bear in mind the above assumptions are based on maintaining record population growth. It seems more likely that in reality a combination of economic and demographic factors over decade will hinder maintaining that rate of growth.
In reality the market would be more likely to correct significantly before oversupply reached anything like 4 times as high as 2011.
But if the market corrects to reflect the fact that we didn't need to build anything close to 35k houses per annum, how do you explain that to the poor sod who bought a house in 2022 with a 30 year mortgage for 425k confident it was a financially sound move because everybody said we didn't have enough houses?