We’ve heard plenty about the rising cost of residential properties in recent months, but it appears that those looking to extend their home are also having to fork out more for the pleasure.

According to the latest Home Improvement Index, the cost of building a home extension increased nationally by 3.23 per cent in the first half of the year when compared with the same period in 2013. As with property prices, it is people in the capital who are coming under the most pressure, with extension costs in Dublin rising by more than 11 per cent in the first six months of 2014.

The index, produced by Onlinetradesmen.ie, also revealed that there are significant differences in extension costs between rural and urban areas.

The national average cost for an extension stands at €981 per sq m. However, the index showed that rural areas have an average cost of €908 per sq m, while an extension in Dublin is the most expensive nationally, with an average build cost of €1,069 per sq m – 15 per cent more expensive than rural equivalents.

In comparison with previous indices, these results show a significant variation in extension build costs compared to previous years. At the peak of the Irish construction sector in 2007, the average extension cost was €1,599 per sq m, 39 per cent higher than the current national average. Conversely, in 2009 the average extension build cost was €770 per sq m – 27per cent lower than the current level.

The index shows that the average extension size nationwide in 2014 is 26 sq m, at an average cost of €25,495. Single-storey kitchen extensions are the most popular extension type nationwide.

"These figures show an increased demand in home extensions," said Ted Laverty, chief executive of Onlinetradesmen.ie. "The improving economy, in addition to the government's Home Renovation Incentive (HRI) scheme, are contributing to the increase. While there is still good value for property owners in completing projects, prices are increasing gradually, particularly in the Dublin region. The new building regulations have certainly impacted on the cost of building larger extensions, with the improved controls ensuring improved standards nationally.

“We would always recommend that property owners ensure that they do not hire a builder based on price alone but check their qualifications, references and insurance cover before they hire them.”

The Construction Industry Register (CIRI) is a free-to-use search facility that lists "competent construction companies in Ireland". ciri.ie