There are very few 3 bed semi's being built in Dublin any more so having a 3 bed semi in a good area with a decent garden is going to be a better investment than an apartment. Just my opinion.
It depends on what you are looking for - a city centre apartment (within the scope of the canals) would be a good investment because young professionals will always want to live near CC and work...
If you are looking twoards the family market a 3 bed semi makes more sense as they will want space and a garden.
It really depends on what you want to aim your investment at...
Pinkybear, I am looking for an investment of about 6-7 years. Property will be used by my student daughters and hopefully renting 1-2 rooms. So rental income is not really an issue. It is capital appreciation that I am concerned with.
With that in mind I would image city centre would be the way to go, if you think of it City Centre dwellings are within busses to DCU, UCD, walking distance to TCD, so your children wont be faced with commuting accross the city for their respective collages....