Attic Conversion

You would not need planning permission as long as you do not change the roof profile, and rooflights are kept to the rear.
If it was going to be for more than storage, i.e. an habitable room, you would need to comply with Building Regulations.

What would the building Regs Require

If it’s just a storage space (ie. it won’t be used as a living room or bedroom) and
(1) you dont put in a dormer window anywhere
(2) you dont put in a velux-type roof window on the side or to the front of the house and
(3) you dont change the profile of the roof,
then it should be exempt from requiring permission.
The existing ceiling may need to be strengthened if it is going to be used as a floor.
If new supporting steelwork is being inserted, it needs to be fire protected as it would be considered a structural element.
If you want to put in more than 2 roof windows, then you may require permission.

Note: If the house is located in a “Conservation area”, (to find out, ask the Local Authority or look up the Local Development Plan map), you have to be more careful- roof lights to the rear may require permission. LIkewise if the house is on the list of protected structures- don’t make any alterations without seeking advice from the L.A. or a professional.

If at least 1/2 the floor area of the new attic room has a ceiling height of at least 2.4m,
then you have the option of considering the room to be a “habitable” room. (ie. It can be used as a bedroom or living room).
If you do, the requirements of the building regulations will need to be met.
At least one rooflight (If permitted by the Local Authority- some don’t allow habitable rooms to receive daylight solely from velux-type rooflights) is required to be an “escape” rooflight. Also a fixed staircase will be required.
There are a number of issues which are spelled out here:
http://www.environ.ie/en/DevelopmentandHousing/BuildingStandards/PublicationsDocuments/FileDownLoad,1657,en.pdf
T.

I’m in nit-pick mode at the moment Tayto, so bear with me.

The height requirement is 2.4M over half the floor area above a cut line of 1.5M in height.

This is explained in Part F 2009 of the building regulations and is not a mandatory height, even for habitable rooms, it is advisory. It can be found on P.11; –

Diagram 3: Suggested height of habitable rooms

http://www.environ.ie/en/Publications/DevelopmentandHousing/BuildingStandar/FileDownLoad,1647,en.pdf

This requirement was more or less the same in the previous version of Part F, IIRC.

There seems to be a current anomaly.

IN part B IIRC the minimum height of a fire escape route is 2.0M clear,

IN Part K the minimum height clearance for a stairs is 2.0M vertically up from the stairs string.

BUT IN Part F from an attic accommodation is 1.9M vertically up from the stairs string.

ONQ.

The 2.4m height over 1/2 the floor area is the accepted standard. Sure- it’s measured at a height of 1.5m over the floor area – what other details did I not provide?

Somebody on another forum, in response to an inquiry in relation to domestic ceiling heights, said:
“These days the Building Regulations merely “suggest” heights, but this is no reason to accept lower standards in terms of either the design or the built work.”

For the life of me I can’t remember who it was….;)