For larger house moves - it is probably best to get a removals company to do the job.
For smaller moves it is worth considering Van Hire - you can get good sized vans for hire in the UK from Europcar or Hertz.
Hire the van in the UK - - load up the furniture and drive over to Ireland using a Ferry (Irish Ferries or Stena have similar prices)
You will probably need to drive the van back to the UK and then you can fly back to Ireland cheaply with one of the many airlines that do cheap flights to Dublin , Knock or Cork