The cost of extending a home has increased by 11pc in Dublin in only 12 months, with 68pc more property owners seeking to build on rather than buy.
The figures, which come from the new Home Improvement Index, focus on growth in the first six months of 2014.
While the cost of extending in the capital is up 11pc, nationally it has increased by only 3.3pc.
Per square metre nationally it costs €981 for an extension. In rural locations, the average cost is €908. In Dublin, it is €1,069.
David Hall, director of the Irish Mortgage Holders' Organisation, said there is a shortage of new properties coming on to the market.
As prices increase, people are finding themselves unable to move, making extending the only option.
"Normally, you have a stepping stone where you move up the ladder, but now people aren't able to do that - they're stuck where they are," said Mr Hall.
"If people are buying places that they're going to be in for life, they should make sure they're affordable and that the extension works are affordable."
However, in spite of the increased cost, the average is nowhere near what it was at the peak of the boom.
The national cost of an extension in 2007 was €1,599 per square metre.
In stark contrast, at the height of the recession, in 2009, the average price nationally was €770 per square metre. It means the cost has increased 27pc in five years.
The index, which was produced by Onlinetradesmen.ie, shows that the average size of an extension this year is 26 square metres and costs around €25,495. Kitchens are the most popular extension.
Mr Hall said the surge in extensions is a reflection of the property market in general, and neither the Government nor the banks are doing anything constructive to ease the current shortage of properties for sale.
"There is no sign of the Government doing anything," he said.
"There is no access to funds and there is no access to property.
"There's a suspicion that the banks have properties on their books that they're not selling so that they can manipulate the market ahead of the stress test in October."