I was told between 130 to 150, but it was last year, I would assume it has come down, but actually also trying to find out
It will of course change with time. And remember even within Ireland (the Republic that is) there will be regional variations particularly with contractor and labour costs (cities expensive, country less so). There will also be differences between types of property (eg psf prices are less for two-storey generally than single storey), finish, utilities available, site issues. HOWEVER in spite of all the generality, the Society of Chartered Surveyors Rebuilding cost estimates might be your best bet and you're looking at around €130-140 psf on "average" in May 2010 (taking out demoliton and clearance costs of about €10-15k). Look at their website for more information.
You may be interested to know that in the UK, the Building Cost Information Service produce a free online calculator and it shows that costs in Northern Ireland in May 2010 are below HALF the cost of the Republic, so if I were you I would really consider hiring a Northern contractor and obtain your building supplies there.
The building cost will obviously exclude the site cost and professional fees. Before the boom the cost of the site was about 15% of the overall cost of the property. And if that were to apply today then for a rural 2500 sq ft property you would be looking at €325k building cost (using the SCS approximations - using the North's you'd be looking at €150k) which would suggest a site cost of €50-60k and in a rural area that should get you an acre. In practice you will find asking prices well above that - €100k for an acre in rural Ireland asking price is not uncommon.
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