It is very important for you to decide at planning stage where all your drains and pipes going to be placed as you do not want to dig the floor or the ground at the later stage to add or change anything.
Do take into consideration all the pipes for your sewage, water , drains , ESB ( which is recommended to be a 4” pipe to the nearest pole ), telephone (similar to ESB ), cable’s and whatever else you think you are going to need.
Do make sure that you have the right size pipes for everything by asking advise from the professionals and suppliers.
The drains and the pipes for the house have to be placed in position before the floor is poured in the house, this would make sure that there are not pipes visible afterwards.
What type of pipes?
In general, the outside pipes are made of PVC unless there is extra need for strength in which case you can use concrete pipes to the measurement required. As for water connections, a heavy gauge black pipe is recommended with either brass or plastic connections which can be very easy to connect and leak proof if installed properly.
For internal use, there are mainly two types which are currently used in Ireland. There is the traditional copper or Qual-pex/Acorn which has been in use for the past few years. There is no reason why both types can not be used in your project as each have advantages of their own.
As far as cost wise there are hardly any differences between them and both will supposedly last for many years to come if installed properly.
As far as ease of use, it has been suggested that Qual-pex/Acorn is easier to work with as it can be cut to the length required from a reel of 100 ft and they are more flexible around obstacles like walls. They have also been proven to be very good against leaks due to the inserts in the connecting points and the pressure washer in the connections. And finally, if chosen for heating they are usually quieter than copper pipes while heating and cooling.
Do remember, if you are installing underfloor heating the pipes have to be placed in the floor before the final finish is done for that floor.