Does a basement count as a storey for fire rated loft hatch requirements

[Thorfun]

my reading has informed me that if a building is 3 storeys then loft hatches must be fire rated. but I can't seem to figure out if a basement counts as a storey? we have a basement, ground floor and first floor with a loft space above the first floor. we have 2 loft hatch requirements. do I need fire rated loft hatches?

[Conor]

Nope*.

 

Reason being the count of floors is from the principle level upwards. No additional fire protection measures needed.

 

*Raised with BCO before drawing submission, there were different opinions before agreement, and under NI regs.

[Thorfun]

3 minutes ago, Conor said:

Nope*.

 

Reason being the count of floors is from the principle level upwards. No additional fire protection measures needed.

 

*Raised with BCO before drawing submission, there were different opinions before agreement, and under NI regs.

thank you and that makes sense. I don't recall our architect ever saying we needed fire rated loft hatches.

 

although, ironically, our hatch holes are 900mm x 600mm and the only off the shelf hatches I can find at those dimensions are fire rated! 🤦‍♂️

 

these https://www.jupiterblue.co.uk/loft-hatches-c2/fire-rated-c13/sd-fire-rated-loft-hatch-part-b-and-part-l-compliant-in-6-sizes-p96

Edited June 16, 2023 by Thorfun
added link

[kandgmitchell]

Agreed. See diagram D5 on page 144 of the Approved Document to Part B Volume 1 - Dwellings (it's on line) You count the number of storeys at the point where it has the greatest number but exclude any basement storeys.