In Ireland the regulations don't specify anything specific but the guidelines, which are generally followed set out:
Kitchen: 10 sockets minimum (goes on to explain that modern kitchens are full of small appliences etc and how the use of double adaptors should be strongly discouraged in such an environment)
(UK style Cooker Control/Socket unit is outlawed under irish regs. There are plenty of them installed but they are not allowed in new installations and if they need replacement they have to be replaced by a normal dual pole switch without a socket.)
Living rooms etc: 4 socket minimum, it also goes on to state that sockets should be located to suit requirements for free standing lamps, television, audio equipment etc to prevent the excessive use of "multisocket adaptors" Basically use common sense and make sure that the normal requirements are met. E.g. some people might put 2 X double plates beside the antenna socket for the TV, it's up to the home owner though.
Hallways (rule of thumb): At least 1 X double, centrally located to allow for use of vacuum cleaners etc and to remove the requirment to use extension cords. If the hallway is very large outlets should be located to allow for vacuum cleaning at points along it. Free standing lighting should also be taken into consideration.
Bedrooms: at least 2 sockets although 2 X double is the recomended minimum, 2 of which should be near the bedside area.
Laundry rooms: 1 outlet dedicated to each large applience and 2 spare.
It's not entirely uncommon to find old houses here with 1 socket in each room!
However, it's worth noting that Ireland is the most litigeous country in the world after the USA. One public housing athority was sucessfully sued and had to pay out major amounts of money for not installing sufficient sockets!
A kid was scalded by a boiling kettle when she pulled the extension cord it was plug in to. This happened in public athority house dating from the late 1800s that only had one socket in the kitchen which was not located directly beside the counter top. The court ruled that the housing athority was at fault, as the family were forced to use long dangerous extension cords and adaptors and rewarded massive dammages. This ruling would potentially apply to anyone with a duty of care.. i.e. landlords, builders, architects and electricians.
