When you go up the stairs into the attic, is it open-format, or do you have a door into it?
If its enclosed, then you need a fire cert, as it counts as an attitional habitable room. 'technically', an attic conversion is not supposed to be used as a bedroom, but as storage. Hence when selling, you must say '3-bed with attic conversion', as opposed to calling it a '4-bed'.
Only if you put the Velux in the front of the house will you need PP.
this advice is incorrect....
firstly, fire safety certificates do not apply to detached, semi detached or terraced dwellings, .....
secondly, if you converted your attic without permission and now want to sell, you will have to apply for planning permission to retain the attic conversion..
thirdly, if the attic room complies with all relevant building regs.. ie ventilation space and fire escape, then you can by all means advertise it as a 4th bedroom...... (in order to comply with ventilation regs, the ceiling level at 2.4 m must be greater than the plane at 1.5 m... plus others.... in order to comply with fire regs the room should be fitted with an escape rooflight in accordance with 1.5 of TGD B...)
forthly, a rooflight fitted to any part of the roof technically needs planning permission.. it is not covered in the 'exempted development' section of the regs... however, this is often (wrongly) ignored by professionals signing off...
fifthly, you can have an open plan arrangement on the first floor (attic space)... the stairs serving the attic conversation has to be enclosed with storey-height construction and must discharge to the open air... this would be the usual situation if the stair is in th emain hall and discharges through the front door to the open air.... if the stair discharges into a room, other regs apply.. again check section 1.5 of TGD B.
http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandards/FileDownLoad,1640,en.pdf
see page 53.