Re: Re: Basements in Ireland

I’m just wondering about the additional costs associated with basements, compared with just building over ordinary foundations. At present my house (end of terrace) has a side extension that’s horrible in just about every conceivable way – appearance, layout, construction quality… I plan to demolish this and replace it with one that’s better designed, and I’m mulling over the possibility of getting extra floor space by including a basement.

From what I’ve read so far, it seems that the cost of retrofitting a basement under the main house would be prohibitive and might also have implications for my neighbours in the terrace. However, if a basement is included in the new extension (just under the new bit) at the time of construction I presume it should be somewhat more cost effective.

Obviously this would have implications for the layout and costs will also vary hugely depending on spec, but could anyone hazard a very, very general guess on how much extra it might cost (either as % or €) to build 2 storeys over basement instead of 2 storeys only? The footprint would basically be a narrow slice between the main house and a tall side wall (I’m guessing about 2.5-3m wide by 9m front to back).

Thanks.