Building Regulations

Rather than having a problem with planning permission, you are more likely to have a problem with adhering to the Building Regulation when converting your attic. This of course depends on the structure of your house. A roof with a high pitch and wide base will usually comply with the main ones. To comply with the Building Regulations in terms of habitable space, 50% of the floor area above 1,500mm (5 feet) should be at least 2.4metres, or 8 ft. That usually doesn't apply with attics. There are not enough attics built with sufficient pitch on the roof to allow for that type of condition to apply. . If you want your conversion to comply with building regulations, that factor needs to be dealt with and may instantly rule out the possibility of conversion. It is very important to stress you adhere to these regulationse because if you convert your attic, and you later sell your house, an architect coming in to inspect the house will point out that the conversion doesn't comply. Therefore, the cost of the conversion and the added value it gives to your home is lost.
Flooring is an important structural issue, because an attic conversion means considering floor loads, and you need to make sure that the floor complies with the Building Regulations in terms of structure. Usually, ceiling joists in an attic are not good enough for the spans they're supporting below. Typically, they're spanning over rooms that might be 12 or 13 ft wide, and are only capable of taking plastered ceilings. They're not usually designed for taking room loads, which means the floor needs to be stiffened up. A lot depends on whether the attic is a trussed rafter attic, with a forest of trussed rafters, with bracing cutting across the space, making it unusable. However, if you have trussed rafters, there are ways of modifying the roof that can replace the trussed rafter structure, by putting in a whole engineered solution that opens up the space. You should have a structural engineer designing and overseeing the work who will certify the work. Otherwise, putting in additional, larger floor joists spanning across is an option, but it does involve raising the floor level of the attic. In the vast majority of cases, the existing ceiling joists won't be capable of requiring with the structural requirements of floors. All structural elements should be designed by a Qualified Building Engineer and certified at each construction stage. The attic floor must be fire protected in addition to being insulated. A fire escape window needs to be fitted with a clear minimum opening of 500mm x 850mm, 1700mm up from you gutter if the attic are being used as bedroom or living space and a full width stairway must be constructed for access to meet fire safety regulations.

Even though you may be a very competent handyman who can successfully undertake an attic conversion, it is essential that you talk to a professional engineer, chartered surveyor, or architect before you make a start. It will cost a few euro, but it could be the best money you ever spent if it means the conversion is finished to legal building standards or that you are advised not to do it at all.