Ceiling height regulations

[dme1]

Hi,

I want to replace my fink roof trusses (7.5 mtr span) with traditional joists and supporting RSJ's. I also want to put the new joists at a lower height, to get more headroom in my new loft storage area.

Does anyone know if I am allowed to lower my first floor ceiling height by 9"? At the moment the height is at 8ft.

 

[DAZB]

I am not completely certain about the upstairs rooms but in the cellars and basements I have converted I aim to get a minimum headroom of 2.1 meters but I also know that any route that can be classed as an escape route (excluding doorways) has to have a clear headroom of at least 2 meters. I don't know if that construes that crossing a room to leave it is an escape route though. In either case you should still be ok as you are aiming for a ceiling height of around 2.2 meters. You will also need to take into account that any changing of roof structure will also alter the loading of the building ( the weight supported by the external walls ) so I strongly suggest having all the relevant plans and permits drawn up. Hope this helps.