New Central Statistics Office figures show that more apartments than houses were granted planning permission in 2020.
Planning permissions were granted for 26,224 apartments last year, a jump of 33.9% on 2019 and the highest number since 2005.
Today's CSO figures shows that planning permissions granted for houses declined annually for the second year in a row in 2020.
A total of 18,314 planning permissions were granted for houses, a decrease of 6.8% compared with 19,651 permissions granted in 2019.
The CSO said that planning permissions were granted for 44,538 homes - both houses and apartments - last year compared with 39,242 homes in 2019, an increase of 13.5%.
But overall, the total number of planning permissions, including for extensions, last year fell by 8.2% to 25,597.
Of this, almost 26% of permissions were for new dwellings, 31% for other new constructions and 43% for extensions, alterations and conversions.
The CSO said that floor area granted for extensions has been steadily declining since 2017.
Permissions were granted for 819,000 square metres of extensions in 2020 compared to 925,000 square metres in 2019.
The CSO also noted that 76.2% of the apartments granted planning permission last year were via Strategic Housing Development (SHD) applications.
This is where applications for developments of at least 100 residential units or 200-plus student bed spaces can be made directly to An Bord Pleanála.
Permissions were granted for 5,910 new houses and 19,989 new apartment units via SHD applications in 2020, it added.
Meanwhile, figures for the fourth quarter of 2020 reveal that planning permissions were granted for 4,432 houses, down 9.5% on the 4,899 houses in the fourth quarter of 2019.
Planning permissions were granted for 5,104 apartment units, compared with 7,195 for the same time in 2019, a decrease of 29.1%.