Building costs for 2 storey extension

I’m currently planning a 2 storey extension to my house and I was wondering if anyone could give me an indication of likely building costs (an average per sq. m. cost). I’ve heard that it’s likely to be higher than the rate for building a complete house, but have no idea by how much.

Is there anyone out there who’s built something similar recently who could give me an indication of how much it’s likely to be? I’d like to get some rough idea before talking to any possible contractors. The floor area of the new extension is about 35 sq. m. on each floor (ground and 1st).

neighbours of ours got a price recently to get a 2 storey extension to the side which would have a room & utility room downstairs with 2 bedrooms above with bathroom in between them for about €110k.
I thought it was a bit much.
Friend of mine got similar job done in Swords a few yrs ago for about €80k

Thanks - it certainly establishes a ballpark.

By the way, I forgot to mention I'm in Dublin.

a handy guide (rough giude) would be 180 per sqft
to 220 per sqft but it depends your finish, remember builders
will charge very different prices for the same job
finished to different levels of quality no doubt.

Is 180 - 220 for a complete finish? I have an offer accepted on a property that we hope to extend on one side. Does this guide price include the roof, electrics, windows ect. We will be getting quotes from builders but I'd like to have some idea before we get plans drawn up. I am really really clueless! We're in Louth.

Thanks.

The word on the street is that it's becoming a bit easier to get builders. Could be a good time to shop around.

Staples said:

The word on the street is that it's becoming a bit easier to get builders. Could be a good time to shop around.

Click to expand...

That's encouraging!

The orighinal question was more about the cost of an extension vs. cost of a house: there's plenty of info, here and elsewhere, on (a) rebuilding costs for insurance purposed etc. and (b) cost of smallish single storey extensions, but not too much on how much a more sunstantial two storey extension would be.

I've heard it's more expensive than building a house from scratch (on a per sq. m. basis), but have no idea how much more: 5%, 10%, 20%?