Planning permissions for apartments have exceeded those for houses for the first time in the country's history, according to the first report from the Office of Planning Regulator (OPR).

There were 40,252 residential units granted permission last year throughout the country with apartments making up 51% of the total.

The report from the OPR - which was set up to oversee the planning process - states that apartments are "key to sustainable urban development".

It said that the Strategic Housing Development (SHD) process was one factor in the increase as it allows large-scale developments to bypass local authorities and go straight to An Bord Pleanála.

The relaxation of rules on apartments - which included increased height and density - was another factor, it stated.

In Dublin, 86% of all residential units given the go ahead last year were for apartments compared to just 24% in Cork.

However, the report expressed concern that most house building in the eastern part of the country was taking place in commuter areas outside the four Dublin local authority areas.

A total of 55% of all houses granted permission in the region were in the four counties of Kildare, Louth, Meath and Wicklow.

The report stated this "poses a challenge to the Government's planning objectives in tackling the sprawl of major urban areas".

The office examined 25 development plans drawn up by local authorities and made 31 recommendations and 16 observations on issues including the better implementation of planning guidelines relating to flood risk and national roads.

Planning Regulator Niall Cussen said proper and effective planning is needed now more than ever in helping national recovery from the Covid-19 pandemic.

"The planning process will play a central role in how our cities, towns and villages develop. This is because over the next six years the OPR will evaluate close to 200 draft plans from around the country to measure how well they align with existing planning policy," he said.

The report stated there was 32,314 valid planning applications made last year and of those decided 90% got approval.

There was an average of 16% that were deemed to be invalid with the percentage ranging from 4% to 29% between planning authorities.

Of the applications 44.5% were in the Eastern Midlands Assembly Area, 37% in the Southern Region Assembly Area and 19% in the North Western Region Assembly area.

There were 91 complaints from members of the public but none were found to be in the OPR's remit as they related to individual planning cases rather than systemic issues.