Hi, Just last year we got under the stairs converted into a cuboard. We got a new wall made up however inside the new cuboard there is a few pannels with white inner layer. I have had good look at it and it has little fibres pointing out! I am assuming this is plasterboard not Asbestos instulation board? I just hope that the builders did not go cheap and used old stock? I will try and put some pictures of it for all to see shortly. Thanks.