Build second house on land, urban Dublin

[David_Dublin]

Living in urban Dublin, have seen someone up the road build a second house on their land. The existing house is end of terrace, they had some space to the side, but the plot is small and wouldn't seem to lend itself to leaving existing and new houses with decent size garden, whereas I understod that there were rules about retaining x number of sq metres of garden, retaining side/back entrance etc when building.

Anyhow, my question is more about the tax side of things - if you and your family live in such a dwelling (the original house) and build a new one beside it (with full planning permission), is there any way to sell both without tax implications? Would they have to be sold separately, and the newly built element subject to CGT or something similar?

 

[Nicetoknow]

I think what people usually do is sell the existing house (their PPR) and move to new house making the new build their PPR, then after 12 months sell the new build house. Im not any kind of financial advisor but I have seen this done by builders looking to avoid tax liability on houses they are developing